A cluster randomised, double-blind pilot and feasibility trial of an active behavioural physiotherapy intervention for acute whiplash-associated disorder (WAD)II

A cluster randomised, double-blind pilot and feasibility trial of an active behavioural... Citation: Wiangkham T, Duda J, Haque MS, Price J, Rushton A (2019) A cluster randomised, double- Whiplash-associated disorder (WAD) causes substantial social and economic burden, with blind pilot and feasibility trial of an active �70% patients classified as WADII (neck complaint and musculoskeletal sign(s)). Effective behavioural physiotherapy intervention for acute management in the acute stage is required to prevent development of chronicity; an issue whiplash-associated disorder (WAD)II. PLoS ONE for 60% of patients. An Active Behavioural Physiotherapy Intervention (ABPI) was devel- 14(5): e0215803. https://doi.org/10.1371/journal. pone.0215803 oped to address both physical and psychological components of WAD. The ABPI is a novel complex intervention designed through a rigorous sequential multiphase project to prevent Editor: Belinda J Gabbe, Monash University, AUSTRALIA transition of acute WAD to chronicity. An external pilot and feasibility cluster randomised Received: October 24, 2017 double-blind (assessor, participants) parallel two-arm clinical trial was conducted in the UK private sector. The trial compared ABPI versus standard physiotherapy to evaluate trial pro- Accepted: March 31, 2019 cedures and feasibility of the ABPI for managing acute WADII in preparation for a future Published: May 9, 2019 definitive trial. Six private physiotherapy clinics were recruited and cluster randomised using Copyright:© 2019 Wiangkham et al. This is an a computer-generated randomisation sequence. Twenty-eight (20 ABPI, 8 standard physio- open access article distributed under the terms of therapy) participants [median age 38.00 (IQR = 21.50) years] were recruited. Data were the Creative Commons Attribution License, which permits unrestricted use, distribution, and analysed descriptively with a priori establishment of success criteria. Ninety-five percent of reproduction in any medium, provided the original participants in the ABPI arm fully recovered (Neck Disability Index�4, compared to 17% in author and source are credited. the standard physiotherapy arm); required fewer treatment sessions; and demonstrated Data Availability Statement: All relevant data are greater improvement in all outcome measures (pain intensity, Cervical Range of Motion, within the paper and its Supporting Information Pressure Pain Threshold, EuroQol-5 Dimensions) except for the Impact of Events Scale files. and Fear Avoidance Beliefs Questionnaire. The findings support the potential value of the Funding: The lead author (TW) would like to thank ABPI, and that an adequately powered definitive trial to evaluate effectiveness (clinical, the Royal Thai Government for the scholarship to cost) is feasible with minor modifications to procedures. support the trial research costs. This funding had no role in any process of this trial and publication. Competing interests: The authors have declared that no competing interests exist. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 1 / 25 Active behavioural physiotherapy intervention for acute WADII Introduction Whiplash-associated disorders (WAD) describe a range of presentations that may be seen fol- lowing whiplash injury owing to a wide variety of possible symptoms.[1] WAD is most com- monly a consequence of road traffic accidents.[1] WAD is a major public health problem, with high annual economic costs estimated as $242 billion for the USA[2] and€180 billion for Europe.[3] Paralleling increasing healthcare costs are reduced work productivity and earning capacity.[4, 5] For example in Denmark, a decline of 20–25% in employment propensity was observed in the 2 years following a whiplash injury.[4] Insurance companies have also reported an increase in whiplash related costs,[6] particularly in the UK where insurance claim costs are considerable as individuals are largely managed within the private sector by the insurance companies.[6–12] The undesirable title of the ‘whiplash capital of Europe’ has been conferred on the UK by the Association of British Insurers, with estimates that 1 in 140 individuals make claims related to whiplash injury annually.[10] A total of 450,000–580,000 whiplash claims have been reported annually from road traffic accidents in the UK,[13] with estimates for the costs of personal injury claims rising from £7 to £14 billion over a 10 year period.[10] Interest- ingly, while the costs of whiplash are increasing, the number of patients experiencing WAD is likely to be stable.[13] These socioeconomic costs are largely explained by up to 60% of individuals with WAD progressing to experience chronic pain and disability; with ~30% people experiencing mod- erate to severe levels of pain and disability.[14–16] A key consequence of chronicity is a decrease in quality of life for individuals,[17, 18] and a resulting increase in time contributed by caregivers.[4, 5] Unfortunately, approaches to both acute and chronic WAD management have demonstrated limited success.[14, 15, 19–21] Effective management in the acute stage is therefore an important challenge to prevent patients with WAD transitioning to chronicity. [19, 22–24] The classification of WAD into 5 grades of severity[1] informs clinical reasoning to target interventions to individual patients. The most common classification accounting for�70% of individuals is WADII; characterised by a neck complaint accompanied by musculoskeletal sign(s).[25, 26] Individuals with WADII classification are commonly managed by physiothera- pists, and in the UK this is usually in the private sector where patients are referred by insurance companies to private physiotherapy clinics.[10] To date, no research has investigated this com- plex private sector context for managing WAD. Therefore, evaluation of the effectiveness of acute WAD management in the private context is a research priority. Our recent rigorous systematic review[22, 23] evaluating the effectiveness of acute WADII management found that the combination of active physiotherapy and behavioural interven- tions termed ‘Active Behavioural Physiotherapy Intervention (ABPI)’, is a potentially effective strategy for the management of acute WADII and may therefore be valuable in preventing chronicity. Unfortunately, the existing evidence was insufficient to define an ABPI interven- tion. Therefore, an ABPI was developed using empirical and theoretical perspectives through a rigorous process in line with the Medical Research Council Framework of Complex Interven- tions.[27] An initial modified Delphi study using expertise from international researchers and UK physiotherapists working with WAD patients[28] defined the individual treatment tech- niques and rehabilitation content of the intervention. Social cognitive theory focusing on self- efficacy enhancement[29] provided the underlying theoretical framework to behaviour change to enable delivery of the intervention. Following development of the ABPI, it was then impor- tant to investigate the feasibility of its use in preparation for a future definitive trial. It was important for the research to focus on the private setting in the UK where most patients are managed.[30] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 2 / 25 Active behavioural physiotherapy intervention for acute WADII Aim To evaluate trial procedures and feasibility of the ABPI in managing acute WADII within the UK insurance private sector to inform the design and sample size requirements for a future definitive RCT. Primary objectives. • To evaluate the feasibility of procedures for a cluster RCT (randomisation, recruitment, data collection, trial management and follow-up)[31–34] • To evaluate recruitment rates in the private sector in the UK[32, 33] • To evaluate loss to follow-up of participants in the private sector in the UK[32, 34] Secondary objectives. • To estimate the required sample size for a clustered definitive trial[32–36] • To evaluate the feasibility of data collection for cost-effectiveness analysis[32] Methods The trial was registered (BioMed Central, ISRCTN84528320) and conducted according to a pre-defined published protocol[37] in order to minimise potential biases, and subsequent deviations were reported. Research methods and reporting were in accordance with the CON- SORT 2010 statement: extension to cluster randomised trials.[38] The trial is reported in line with the CONSORT 2010 statement: extension to randomised pilot and feasibility trials[39] (although the CONSORT statement was published after the protocol was developed). Trial design As described in detail previously[37] an external pilot and feasibility trial of a cluster rando- mised double-blind (assessor, participants), parallel two-arm design, comparing ABPI with standard physiotherapy management, was conducted to evaluate procedures and feasibility of the ABPI (with an embedded qualitative study reported elsewhere). Six private physiotherapy clinics in the West Midlands, UK were recruited. There are many advantages to cluster rando- misation in terms of administrative convenience,[40] obtaining the cooperation of investiga- tors, ethical considerations,[40] enhancing participant adherence, reducing treatment contamination,[30, 38, 40, 41] participant blinding,[38] and logistical conveniences.[40] How- ever, the required sample size in a cluster RCT is larger than a parallel design RCT.[42] In line with the published protocol,[37] 6 private physiotherapy clinics were invited to sign consent forms (cluster-level consent) prior to cluster randomisation.[38] The physiotherapy clinics were randomly allocated to either ABPI or standard physiotherapy by a computer-gen- erated randomisation sequence. Following randomisation, consecutive potential participants referred by an insurance company to the clinics, were screened and recruited by a clinical administrator by telephone to book an initial recruitment appointment. The participant infor- mation sheet and consent form were sent via email/post to give potential participants the opportunity to read it in advance of the appointment. During the appointment, the recruiting physiotherapist discussed any issues relating to the trial, afforded an opportunity to ask ques- tions, confirmed eligibility and obtained written consent (individual-level consent). After giving informed written consent, participants were assessed on all outcome measures by a blinded assessor using standardised instruments with established measurement properties. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 3 / 25 Active behavioural physiotherapy intervention for acute WADII Assessments were made at baseline (following recruitment and consent) and at 3-months post baseline (planned primary endpoint for future definitive trial, the patients with WADII who continue with symptoms and problems after 3 months were defined as chronic).[15, 43] All outcome assessments were independent from treatment sessions and treatment clinics to ensure that the assessor was blinded to treatment allocation. The assessor was a physiotherapist familiar with and trained in use of the outcome measures, and blinded to reduce potential biases. The assessor was not able to access the booking system and participants’ information, while participants did not know to which intervention arm they were allocated, to ensure that both assessor and participants were blinded. To evaluate blinding, at the end of the 3-month follow-up for each participant, the assessor was asked which intervention they thought the patient had received, and the participants were asked which intervention arm they had been allocated to. Two assessment centres central to all clinics enabled convenient attendance for participants. The participants received a text message reminder 2 days prior to the baseline assessment and 3-month follow-up appointments. As part of the consent form, participants were asked to confirm whether they would like their data removed or kept in the trial in the sit- uation that they decided to withdraw (please see online supplementary appendices for the par- ticipant information sheet and consent form in the protocol[37]). Participants were invited to provide a reason for their withdrawal. Participants Participants were recruited from the 6 UK private physiotherapy clinics. Demographic charac- teristics, including age, gender, accident history, present drugs, and information regarding WAD symptoms were collected by the recruiting physiotherapist at the baseline assessment. Participants could claim all expenditure relating their treatment sessions from their insurance company. The trial therefore reimbursed participants for journeys at baseline and 3-month fol- low-up that were additional contact points. Eligibility criteria for clusters: private physiotherapy clinics in the West Midlands region of the UK. Preliminary data had identified that each clinic had�2 patients a month presenting with acute WADII. Inclusion criteria: Participants aged between 18–70 years presenting with WADII[1] from a road traffic accident within the previous 4 weeks.[15, 23, 43–46] Exclusion criteria: Signs and symptoms of upper cervical instability[47] or cervical artery dysfunction,[48] suspected serious spinal pathology, open wounds, active inflammatory arthri- tis, tumours, infection of the skin and soft tissue, bleeding disorders or using anti-coagulant medication,[47] any current or previous treatment from any other third party, or presenting with any serious injuries from other areas of the body resulting from the accident, history of cervical surgery,[49] previously symptomatic degenerative diseases of the cervical spine within 6 months prior to the road traffic accident,[50] previous history of whiplash or other neck pain,[45] alcohol abuse,[50, 51] dementia,[50, 51] serious mental diseases,[50, 51] psychiatric diseases,[52, 53] and/or non-English speaking and reading. Eligibility criteria were consistent with the published protocol.[37] Interventions Interventions are detailed in line with the Template for Intervention Description and Replica- tion (TIDieR)[54] and trial protocol.[37] Participants in both trial arms attended for face-to- face physiotherapy sessions in a private physiotherapy clinic lasting up to 30 minutes once a week. The total number of treatment sessions varied between 6 to 8, based on the individual physiotherapist’s assessment of the patient’s problems. All physiotherapists in both intervention PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 4 / 25 Active behavioural physiotherapy intervention for acute WADII arms were registered with the UK Health and Care Professions Councils (HCPC), and pos- sessed a minimum of a Bachelor Degree in Physiotherapy and�2 years post-registration experience. Fidelity of the ABPI was assessed through the systematic collection of a summary of treatment sessions, and the random observation of sessions by the principal investigator (TW). This enabled monitoring and feedback regarding the intervention to the treating physiotherapist. Standard physiotherapy intervention. Patients were managed according to current prac- tice reflecting the recommendations provided in the clinical whiplash guidelines.[43, 46, 55] Physiotherapy interventions such as reassurance, education, manual therapy, exercise therapy and physical agents, including a home programme of exercises, were part of management depending on the physiotherapist’s decision-making for the individual patient. The treating physiotherapists selected appropriate interventions based on examination findings and clinical reasoning.[48] Active Behavioural Physiotherapy Intervention (ABPI). The ABPI was developed through the modified Delphi study[28] and social cognitive theory focusing on self-efficacy enhancement.[29] The ABPI consisted of 4 phases in terms of the promotion of understand- ing, maturity, stamina, and coping.[37] Detail of the ABPI is provided in the published trial protocol.[37] The number of treatment sessions in each phase varied depending on an individ- ual patient’s presentation and problems based on the physiotherapist’s clinical reasoning. Physiotherapists could use a range of techniques (e.g. exercise, relaxation techniques, manual therapy) as part of their ABPI multimodal intervention based on their assessment of an indi- vidual patient’s problems using their clinical reasoning. The recommendation was 1–3 visits in each phase.[56] Physiotherapists were trained to deliver the ABPI in advance of data collection. Training consisted of a group tutorial and workshop followed up with individual training sessions to enable them to tailor the intervention to individual patients with acute WADII based on the findings from the patient history and physical examination data, and their evidence- informed clinical reasoning.[48] The physiotherapists had 4 weeks to practice the skills embedded in the ABPI prior to commencement of participant recruitment. They were ran- domly observed by TW every week before recruitment commenced and every month during data collection to ensure fidelity of the novel intervention. Feedback was provided through- out the trial. Outcomes As described in detail previously,[37] a range of outcomes were assessed. Primary outcome measure. The Neck Disability Index (NDI) is a patient-reported out- come measure and a valid, reliable and responsive tool for assessing pain and disability of the neck in both acute and chronic conditions.[57–60] It is a self-administered questionnaire con- sisting of 10 sections focused on pain intensity and functional activities including personal care, lifting, reading, headache, concentration, work, driving, sleeping and recreation.[57] Each section is scored from 0 to 5, with 5 representing the greatest disability. The sum across all sections is calculated to indicate the participant’s self-reported level of disability.[57] The NDI is a robust predictor of outcome for acute WAD[61] and is recommended for monitoring patients with WAD by several clinical guidelines, including the NHS Library, New South Wales Motor Accidents Authority, British Columbia Physiotherapy Association, Royal Dutch Society for Physical Therapy and the South Australian Centre for Trauma and Injury.[43, 46, 59] Consequently, the NDI has been used as the primary outcome in several previous whiplash intervention trials.[20, 21, 45] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 5 / 25 Active behavioural physiotherapy intervention for acute WADII Secondary outcome measures Visual Analogue Scale (VAS) for pain intensity: The most common complaint from patients with WAD is pain.[9] Pain was measured using a Visual Analogue Scale (VAS) from 0mm (no pain) to 100mm (worst possible pain).[62] It is the preferred tool for assessing pain intensity, being simple, and with established high validity and reliability in evaluating acute pain.[63–65] Use of the VAS to identify initial pain intensity has been supported as an important prognostic factor for predicting poor recovery in patients presenting with acute WAD.[61, 66] Cervical Range of Motion (CROM): Decreased cervical range of motion (CROM) is a common finding in patients presenting with WADII.[67] The measure is sensitive and can discriminate between asymptomatic people and symptomatic whiplash patients,[68] and for handicap prediction from acute whiplash injury.[69] CROM was measured using the cervical range of motion device;[70] a valid and reliable device attached to the head[71–73] while the participant sits on a comfortable chair with both hips and knees flexed to 90˚. CROM measure- ments were recorded 3 times in each direction of motion. The mean of the 3 measurements was used for data analysis. Pressure Pain Threshold (PPT): Pressure pain threshold (PPT) was measured to identify the threshold of stimulating pain.[74] Patients with WAD frequently reported central hyper- excitability in both acute (�1 month)[75–77] and chronic presentations.[78] Investigation of PPT at remote pain-free muscle sites provides information on hypersensitivity that may originate from central sensitisation.[79] PPT was measured at symptomatic areas and distal pain-free areas using a digital pressure algometer; a valid and reliable instrument to detect sensitivity.[80, 81] The force was applied at a speed of 30 kPa/s[77] and participants were asked to press a button when their perceived sensation changed from pressure to pain.[77] PPT was assessed at the insertion of the levator scapulae[77] and the upper one-third of the tibialis anterior muscle[81] bilaterally 3 times, with an interval of 1 minute between each measurement.[82, 83] The mean of the 3 measurements was used for data analysis. Positions for testing were comfortable upright sitting with hip and knee flexion to 90˚ for the levator scapulae, and supine lying with the knee of the assessed side flexed to 90˚ for the tibialis anterior. Impact of Events Scale (IES): The Impact of Event Scale (IES) is a 15-item questionnaire assessing current stress and symptoms of post-traumatic stress that may contribute to a high risk of persistent symptoms.[52, 84–86] The IES possesses established reliability and validity,[87–89] and is recommended by guidelines for monitoring whiplash management. [43, 46] Fear Avoidance Beliefs Questionnaire (FABQ): It is well documented that fear avoidance beliefs and associated behaviours following whiplash injury can influence the physical disabil- ity of patients with WAD.[90–92] Patients with any dysfunctional illness beliefs need to have these addressed as part of their management to prevent development of chronicity.[93] The Fear Avoidance Beliefs Questionnaire (FABQ) is a 16-item tool with established reliability and validity for use in populations with neck pain[94]. It is focused to the assessment of a patient’s perceptions of the impact of physical activity and work on their perceived levels of pain and disability[90]. EuroQol-5 Dimensions (EQ-5D): The EQ-5D is a valid and reliable self-report quality of life [95] questionnaire.[96] It is recommended as a useful tool for measuring generic QoL in order to provide information for cost-effectiveness analysis.[97] The EQ-5D has been trans- lated into many languages.[98] In the whiplash literature, the EQ-5D has been used to provide information for cost-effectiveness analysis in one large RCT,[21] directly informing this trial. [37] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 6 / 25 Active behavioural physiotherapy intervention for acute WADII Assessment of outcome Blinded assessment of outcomes took place at baseline and at 3-months post baseline. After 3 months, the patients with WAD who continued to experience symptoms and problems were defined as chronic.[15, 43] The number of fully recovered patients at 3 months was evaluated. Participants who did not attend the 3-month follow-up assessment were contacted by tele- phone to make a new appointment. In the situation where participants could not make a new appointment, the assessor asked them to complete the NDI[99] and EQ-5D[100] via telephone interview; both outcomes have established reliability and validity via telephone. Feasibility of cost-effectiveness analysis To assess the feasibility of data collection for the planned cost-effectiveness analysis of a definitive trial, both direct and indirect medical costs were collected. Participants received a diary pocket book to enable recording of any activities related to whiplash management including: medication use, healthcare professional consultations along with any costs they incurred, days off sick, received benefits related to WAD management. General information about participants (including post code, work status and income) was collected on the first page of the diary. Physiotherapy management related costs were collected directly from the physiotherapy clinics. The training costs of physiotherapists in the experimental ABPI trial arm were recorded. Sample size Consistent with this being a pilot and feasibility trial, a power calculation was not required. [32] There is considerable debate around establishing adequate sample sizes for pilot/feasibility trials, and the planned recruitment was for 60 participants (30 in each arm) in order to provide sufficient power of parameters for designing an adequately powered definitive RCT.[101] Physiotherapy clinic data provided evidence of n = 18 eligible participants available each month across the 6 participating clinics. The recruitment rate of the trial was considered ade- quate if�50% of eligible participants were recruited. Based on these estimates, it was antici- pated that the trial duration would be 6–7 months for recruitment combined with the 3-month follow-up. Randomisation To minimise the risk of selection bias at the cluster level, Stata software version 12 with block- ing, was used to randomise the 6 private physiotherapy clinics into the 2 trial arms: standard physiotherapy intervention (n = 3 clinics) and ABPI (n = 3 clinics). The allocation was con- cealed prior to assignment, with TW the only investigator involved in the process. Cluster ran- domisation was implemented in advance of participants being recruited. Data analysis As detailed in the published protocol,[37] data were analysed and summarised using a quanti- tative synthesis to evaluate eligibility, recruitment and follow-up rates, using IBM SPSS version 22. Consistent with the pilot and feasibility nature of this trial, data were analysed descriptively at the participant level. Descriptive statistics enabled assessment of the feasibility of the ABPI for acute WADII management.[33] Participants who received other treatments from the initial randomised treatment allocation, were retained and their data were included in intention-to- treat analyses. The planned primary endpoint of the future trial is evaluation of the NDI at 3-month follow-up. The intra-cluster correlation coefficient (ICC) was also calculated in order PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 7 / 25 Active behavioural physiotherapy intervention for acute WADII to prepare information for sample size calculation within a clustered definitive trial.[38] The analysis and findings of the quantitative data were discussed by the Acute Whiplash Injury Study (AWIS) steering and data monitoring committee at key stages. A priori feasibility criteria for progressing to definitive trial were defined (see protocol [37]). Upon completion of the pilot and feasibility trial, the following decisions were possible: • Stop if the main trial is not possible or valuable • Continue but modify the protocol if the main trial is possible and valuable • Continue without modifications but monitor closely if the main trial is possible and valuable with close monitoring • Continue without modifications if the main trial is possible and valuable.[33] Trial management and monitoring The trial was managed by a Trial Management Group consisting of TW, AR, JD and SH. The Trial Steering Committee and the Data Monitoring Committee functions were combined in line with the trial’s pilot and feasibility nature into the AWIS Steering Group, consisting of TW (principal investigator), AR (chief investigator, lead supervisor, experienced trialist), SH (statistical expert), JP (physiotherapist), a WADII patient, an external member (internationally published whiplash researcher), and an independent chair. The committee met at the start of recruitment, after 3 months of recruitment, and at the completion of data collection. The prin- cipal investigator was qualified in Good Clinical Practice [an achievement from the Interna- tional Conference on Harmonisation of Good Clinical Practice (ICH GCP), certificate number: 33951-36-41796]. Adverse events For this trial, adverse events were considered as low risk as WADII is not normally a cause of serious adverse events.[19, 21] In addition, both the ABPI and standard physiotherapy inter- ventions were conservative treatments without existing reporting of serious adverse events.[19, 21] Consequently, patients were unlikely to receive any serious harm from either intervention. In general, only minor adverse events are anticipated after physiotherapy intervention, the most commonly reported being muscle soreness, which usually recovers within 1–2 days.[102] Serious adverse events This trial had a very low risk of serious adverse events in terms of patient pathology, treatment nature and treatment management as only WADII patients were recruited. Participants were evaluated by a physiotherapist prior to seeking consent to ensure that participants were accu- rately classified as WADII (and so presented only with musculoskeletal signs, with no neuro- logical signs), ensuring that patients with high severity WAD were excluded. In addition, training ensured that all physiotherapists in this trial managed the patients informed by the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT) cervical framework,[48] a clinical reasoning framework to identify the risk of adverse events regarding and cervical artery dysfunction of the neck. The definition of a serious adverse event was wors- ening symptoms within 3 days and being admitted to the hospital due to whiplash problems. In the event of a serious adverse event occurring, participants were able to continue with the trial when their symptoms were resolved. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 8 / 25 Active behavioural physiotherapy intervention for acute WADII Procedures for reporting adverse and serious adverse events All clinics were provided with an adverse event reporting form. If a participant experienced any unpleasant symptoms, they were asked to report them to their treating physiotherapist. Physiotherapists were required to report any event to TW within 24 hours, and TW was required to report to the AWIS steering committee within 24 hours. This enabled prompt anal- ysis of the event and decision-making regarding any required action. Although not antici- pated, any unexpected serious adverse events were required to be immediately reported with an immediate written form and verbal contact by the physiotherapist to TW. Subsequently, TW would report any event to the AWIS steering committee immediately. Research governance The trial maintained research governance by using the principles of the Research Governance Framework for Health and Social Care, in line with University procedures. Data management All information collected about and from the participants was kept safely from any third party to maintain participants’ privacy. All collected documents were stored in a secure place at the School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham. All elec- tronic data were confidentially stored in a password-protected computer. Data could only be accessed by leading members of the research team. All data will be securely destroyed after 10 years. Ethical and R&D considerations NHS ethical approval and R&D approval were not required as the trial sites were in the private setting, outside of the UK National Health Service. The insurance/private clinics did not require further regulatory approval. Written support for the trial was put in place by the pri- vate clinics and the insurance companies. Ethical approval was provided by the University of Birmingham Research Ethics Committee following their detailed review (ERN_15–0542). Results Participant recruitment Twenty-eight patients were recruited between 06/11/2015 and 01/07/2016 and were followed up for a 3-month period. The trial was stopped early by consensus from the AWIS Steering Group owing to timescale, budget and a reduction of the number of referrals. Two hundred and forty (136 in the ABPI arm and 104 in the standard physiotherapy arm) potential partici- pants were assessed for eligibility by the administrators. Table 1 provides the issues affecting participants’ decisions to not participate in this trial and the administrator’s decision. Reasons for patients’ ineligibility included: ‘post four weeks after road traffic accident’, ‘serious symp- tom(s) in other regions of the body besides the neck’, ‘having treatment with another clinic’, ‘history of cervical surgery’ and ‘non-English speaking’. Reasons for potential participants declining included: ‘did not want to participate’ and ‘work commitment’. Other reasons included: ‘unable to book initial assessment within four weeks’ and ‘did not want to travel to assessment centre (different physiotherapy clinic)’. Twenty-seven in the ABPI arm and 13 in the standard physiotherapy arm eligible partici- pants were booked to attend the initial assessment to confirm eligibility, provide consent and enable baseline assessment data to be collected. Seven eligible participants from the ABPI arm and 5 from the standard physiotherapy arm could subsequently not attend this initial PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 9 / 25 Active behavioural physiotherapy intervention for acute WADII Table 1. Issues affecting participants’ decision to not participate (based on administration data). Category of reasons ABPI Standard PT (n = 109) (n = 91) Reasons for ineligibility (obtained from clinical admin team) ➢ Post four weeks after road traffic accident 54 42 ➢ Serious symptoms in other regions 10 6 ➢ Having treatment with another clinic 8 4 ➢ History of cervical surgery 3 2 ➢ Non-English speaking 1 - Reasons for declining (obtained from patients by clinical admin team) ➢ Did not want to participate 10 12 ➢ Work commitments 19 22 Other reasons ➢ Unable to book initial assessment within four weeks 2 1 ➢ Did not want to travel to assessment centre (different physiotherapy clinic) 2 2 ABPI, active behavioural physiotherapy intervention; PT, physiotherapy. https://doi.org/10.1371/journal.pone.0215803.t001 appointment. Their reasons are provided in Table 2. Therefore, 28 out of 40 eligible patients with acute WADII gave their consent and were entered into the trial (20/27 (74.07%) in the ABPI arm and 8/13 (61.54%) in the standard physiotherapy arm). The CONSORT diagram (Fig 1) presents participant progression through the trial. Baseline data Characteristics of participants by intervention arm. The median age of participants was 38.00 (range 22 to 70, IQR: 21.50) years. Table 3 presents the participants’ characteristics by intervention arm at baseline. The median ages of participants in the ABPI and standard phys- iotherapy arm were 34.00 (IQR = 16.00, range: 22 to70) and 50.50 (IQR = 18.75, range: 26 to 70), respectively. More males were recruited to the ABPI arm than females (17:3), whereas there were more females than males in the standard physiotherapy arm (2:6). White British was the most common ethnic group represented in both arms. Characteristics of physiotherapists by intervention arm. Table 4 presents characteristics of physiotherapists by intervention arm. The median ages of physiotherapists in the ABPI and standard physiotherapy arms were 27 (IQR = 0, range: 23 to 31) and 28 (IQR = 0, range: 26 to 30) years, respectively. All physiotherapists in the ABPI arm were male. Two Britons qualified Table 2. Eligible patients interested in participating but unable to attend recruitment. Category of reasons ABPI arm Standard physiotherapy arm (n = 7) (n = 5) WB ML SH GB BC SC Travel issues to assessment centres 3 - - 1 1 - Work commitment - 1 2 - - 2 Booking patients would like to reschedule - - 1 - - 1 but unable to book an initial assessment within 4-week post injury ABPI, active behavioural physiotherapy intervention; WB, West Bromwich; ML, Moseley; SH, Solihull; GB, Great Barr; BC, Birmingham City; SC, Sutton Coldfield. https://doi.org/10.1371/journal.pone.0215803.t002 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 10 / 25 Active behavioural physiotherapy intervention for acute WADII Fig 1. CONSORT flow diagram (adapted from CONSORT 2010). https://doi.org/10.1371/journal.pone.0215803.g001 Table 3. Participants’ characteristics by intervention arm at baseline. Demographic category ABPI Standard physiotherapy (n = 20) (n = 8) Age (range, median (IQR)) 22 to 70, 34.00 (16.00) 26 to 70, 50.50 (18.75) Gender (male:female) 17:3 2:6 Ethnic group White (n = 9) White (n = 6) Asian (n = 7) Asian (n = 1) Chinese or other (n = 2) Chinese or other (n = 1) Black (n = 1) Mixed (n = 1) ABPI, active behavioural physiotherapy intervention. https://doi.org/10.1371/journal.pone.0215803.t003 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 11 / 25 Active behavioural physiotherapy intervention for acute WADII Table 4. Characteristics of physiotherapists by intervention arm. Categories ABPI Standard physiotherapy (n = 3) (n = 3) Age (years) Median (IQR) 27.00 (0.00) 28.00 (0.00) Range 23 to 31 26 to 30 Gender (male:female) 3:0 2:1 Ethnicity (n) British (2) British (1) Greek (1) Greek (2) Physiotherapy qualification (n) Bachelor (2) Bachelor (2) Master (1) Master (1) Physiotherapy years of experience Median (IQR) 3.00 (0.00) 3.00 (0.00) Range 2 to 4 2 to 6 ABPI, active behavioural physiotherapy intervention; IQR, interquartile range. https://doi.org/10.1371/journal.pone.0215803.t004 with bachelor degrees in physiotherapy and one Greek qualified with a master degree in advanced musculoskeletal physiotherapy delivered the ABPI. One Briton (male) and one Greek (female) qualified with bachelor degrees in physiotherapy and one Greek (male) quali- fied with a master degree in advanced musculoskeletal physiotherapy delivered the standard physiotherapy. The physiotherapists’ duration of experience post qualification was the same in both arms, with a median of three (IQR = 0, range of the ABPI arm: 2 to 4, range of the stan- dard physiotherapy: 2 to 6) years. Numbers analysed. For each group, all participants were analysed based on their original assigned intervention arms (Fig 1: CONSORT diagram). Outcomes and estimation Primary and secondary outcome measures. Primary and secondary outcome measures at baseline and 3 months are descriptively presented in Tables 5 and 6 (baseline scores of par- ticipants followed up and lost to follow-up). At 3 months, scores on the NDI, VAS (pain inten- sity), IES, FABQ, and EQ-5D total and subscales were reduced in both trial arms. The only exception was the usual activities subscale of the EQ-5D, where no difference was observed between baseline and 3-month follow-up scores in the standard physiotherapy arm. The EQ- 5D VAS scores in both trial arms were improved at 3 months compared with baseline. Simi- larly, physical assessments (all planes of CROM and PPT of the levator scapulae and tibialis anterior muscles) were improved in both intervention arms. At the 3-month follow-up by intervention arm, the NDI, VAS (pain intensity), IES, EQ-5D (total and all subscales) were reduced in the ABPI arm more than in the standard physiother- apy arm. However, the standard physiotherapy arm had a lower score in the FABQ than in the ABPI. The scores of EQ-5D VAS and physical assessments in the ABPI arm were improved more than the standard physiotherapy arm, with the exception of sagittal cervical movement. The median of difference in each outcome measure is descriptively provided in Table 5. The NDI, VAS (pain intensity) and EQ-5D total and all subscales in the ABPI arm were reduced more than the standard physiotherapy arm. Moreover, the EQ-5D VAS, CROM all directions and PPT bilaterally for both the levator scapulae and tibialis anterior muscles (except for the left tibialis anterior muscle, which exhibited greater improvement in the stan- dard physiotherapy arm than in the ABPI arm) improved more in the ABPI arm when con- trasted to the standard physiotherapy arm. However, the psychological outcome measures PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 12 / 25 Active behavioural physiotherapy intervention for acute WADII Table 5. Primary and secondary outcome measures at baseline and three-month follow-up. Outcome measures ABPI Standard physiotherapy Baseline 3-month Median of Baseline 3-month Median of (n = 20) Median difference (n = 8) Median difference Median (IQR) (IQR) (IQR) Median (IQR) (IQR) (IQR) NDI 17.50 (18.00) 1.00 (2.75) 16.50 (17.25) 21.50 (15.50) 8.00 (8.75) 6.50 (12.50) n = 20 n = 6 VAS 55.50 (29.50) 3.50 (8.25) 48.50 (37.25) 47.00 (31.25) 14.50 (14.75) 37.00 (49.75) n = 6 n = 4 IES 29.50 (31.75) 7.50 (30.50) 13.50 (22.00) 48.00 (32.25) 26.00 (49.75) 24.00 (36.50) n = 6 n = 4 FABQ 60.00 (25.00) 38.00 (19.24) 9.50 (33.00) 61.50 (22.25) 25.50 (19.75) 22.00 (31.00) n = 6 n = 4 EQ-5D Total 11.00 (5.50) 6.00 (1.75) 5.50 (4.75) 10.50 (7.00) 8.50 (4.50) 2.00 (3.00) n = 20 n = 6 EQ-5D Mobility 2.00 (2.00) 1.00 (0.00) 1.00 (1.75) 2.50 (1.75) 1.00 (1.25) 0.50 (1.25) n = 20 n = 6 EQ-5D Self-care 2.00 (1.75) 1.00 (0.00) 1.00 (1.00) 2.00 (0.75) 1.00 (1.00) 0.00 (0.25) n = 20 n = 6 EQ-5D Usual activities 3.00 (1.75) 1.00 (0.00) 1.50 (1.00) 2.00 (1.00) 2.00 (0.25) 0.00 (0.25) n = 20 n = 6 EQ-5D Pain/discomfort 3.00 (0.75) 1.00 (1.00) 2.00 (1.00) 3.00 (1.75) 2.00 (0.50) 0.00 (1.00) n = 20 n = 6 EQ-5D Anxiety/depression 2.00 (2.00) 1.00 (0.00) 1.00 (1.00) 2.50 (1.00) 1.50 (2.50) 0.00 (2.25) n = 20 n = 6 EQ-5D VAS 57.50 (32.50) 98.50 (8.00) 27.00 (24.75) 67.50 (45.50) 75.50 (34.75) -2.00 (19.00) n = 20 n = 6 CROM Flexion 22.50 (7.67) 46.50 (15.50) 27.67 (14.00) 29.00 (13.24) 47.00 (25.34) 17.34 (21.01) n = 6 n = 4 CROM Extension 22.83 (17.58) 36.50 (30.50) 21.17 (23.59) 19.83 (24.83) 46.33 (24.50) 14.83 (35.33) n = 6 n = 4 CROM Left rotation 29.67 (18.33) 54.00 (16.08) 22.00 (28.42) 40.67 (25.01) 49.67 (24.50) -1.00 (26.00) n = 6 n = 4 CROM Right rotation 30.67 (17.83) 53.34 (25.17) 32.00 (26.91) 36.34 (22.16) 45.00 (17.34) 4.34 (12.00) n = 6 n = 4 CROM Left lateral flexion 22.34 (13.33) 34.17 (8.67) 11.50 (16.58) 26.00 (12.83) 26.67 (12.67) 1.17 (13.25) n = 6 n = 4 CROM Right lateral flexion 22.67 (11.84) 36.50 (10.75) 11.17 (15.50) 22.17 (10.84) 29.34 (8.42) 6.67 (8.08) n = 6 n = 4 PPT Left levator scapulae 74.67 (71.75) 168.67 (180.66) 90.33 (110.99) 58.67 (36.66) 109.34 (71.08) 63.67 (79.67) n = 6 n = 4 PPT Right levator scapulae 71.50 (69.66) 197.17 (157.50) 121.50 (118.33) 77.17 (44.00) 134.00 (67.59) 49.67 (83.09) n = 6 n = 4 PPT Left tibialis anterior 106.17 (101.08) 223.17 (228.33) 49.84 (129.75) 103.17 (41.08) 168.00 (233.42) 72.67 (192.42) n = 6 n = 4 PPT Right tibialis anterior 90.17 (110.34) 211.84 (233.50) 101.01 (105.00) 88.50 (24.51) 163.67 (181.91) 86.00 (160.58) n = 6 n = 4 ABPI, Active Behavioural Physiotherapy Intervention; NDI, Neck Disability Index; VAS, Visual Analogue Scale; IES, Impact of Events Scale; FABQ, Fear Avoidance Belief Questionnaire; EQ-5D, EuroQol-5 Dimensions; CROM, cervical range of motion; PPT, Pressure Pain Threshold. https://doi.org/10.1371/journal.pone.0215803.t005 (IES and FABQ) were improved more in the standard physiotherapy arm than in the ABPI arm. At the 3-month post baseline follow-up, 19/20 (95%) participants in the ABPI arm were fully recovered (NDI�4). In the standard physiotherapy arm, 1/6 participants (~17%) was PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 13 / 25 Active behavioural physiotherapy intervention for acute WADII Table 6. Secondary outcome measures at baseline of followed up and lost to follow-up participants. Outcome measures ABPI Standard physiotherapy Followed up Lost to follow-up Followed up Lost to follow-up (n = 6) (n = 14) (n = 4) (n = 4) Median (IQR) Median (IQR) Median (IQR) Median (IQR) VAS 58.00 (33.00) 52.50 (32.50) 54.50 (48.00) 46.00 (46.25) IES 25.50 (26.25) 37.00 (33.50) 50.00 (13.25) 33.50 (41.25) FABQ 53.00 (30.00) 62.50 (23.25) 59.00 (29.75) 61.50 (20.00) CROM Flexion 22.33 (9.26) 23.34 (8.92) 26.17 (13.67) 29.17 (20.83) CROM Extension 18.00 (29.58) 23.33 (12.67) 28.83 (22.51) 12.67 (24.75) CROM Left rotation 29.00 (21.34) 29.67 (18.83) 45.34 (11.17) 24.67 (25.17) CROM Right rotation 16.17 (24.67) 31.84 (14.83) 41.00 (22.67) 25.00 (23.50) CROM Left lateral flexion 21.00 (20.17) 22.34 (11.67) 26.67 (3.41) 19.17 (21.00) CROM Right lateral flexion 20.33 (21.75) 22.67 (9.83) 22.17 (16.00) 22.34 (14.42) PPT Left levator scapulae 75.00 (121.84) 74.67 (68.16) 58.50 (32.92) 66.67 (64.08) PPT Right levator scapulae 69.84 (204.92) 71.50 (53.66) 79.83 (33.00) 60.17 (61.17) PPT Left tibialis anterior 124.67 (128.42) 99.67 (95.33) 102.67 (61.33) 110.67 (40.83) PPT Right tibialis anterior 110.67 (157.58) 86.17 (83.83) 81.50 (25.34) 97.17 (31.50) ABPI, Active Behavioural Physiotherapy Intervention; VAS, Visual Analogue Scale; IES, Impact of Events Scale; FABQ, Fear Avoidance Belief Questionnaire; CROM, cervical range of motion; PPT, Pressure Pain Threshold. https://doi.org/10.1371/journal.pone.0215803.t006 fully recovered. Within the subgroup of participants who provided face-to-face assessment at the 3-month follow-up, 5/6 (~83%) participants in the ABPI arm were fully recovered. In the standard physiotherapy, no (0/4) participants were fully recovered. Table 6 enables a compari- son of baseline data for participants followed up versus those lost to follow-ups. Information regarding cost-effectiveness. Table 7 provides information about the cost- effectiveness of the 2 treatment arms, and illustrates that the number of treatment sessions and physiotherapy management costs in the ABPI arm were lower than in the standard physiother- apy arm. However, the physiotherapists in the ABPI were trained to deliver the intervention, which cost approximately £200. Only 2 participants in the ABPI arm and none of the participants in the standard physio- therapy arm returned their diary pocket book, and so the data are not reported. Coefficient of intracluster correlation (ICC) and sample size calculation for a cluster RCT. The ICC was calculated using the NDI (primary outcome measure) to inform the design effect or inflation factor[103] prior to calculation of the sample size for a cluster RCT. Based on the findings of this pilot and feasibility trial (variance between clusters = 16.574, vari- ance within clusters = 25.367 + 3.116 = 28.483), ICC = 0.368, Design Effect or inflation fac- tor = 4.312 (using cluster size = 10), the required sample size for a definitive RCT is 22 patients per arm based on power = 90%, significance level = 0.05 and difference of NDI = 8 based on Table 7. Cost-effectiveness information. Categories ABPI Standard physiotherapy (n = 20) (n = 8) Treatment sessions (median, IQR) 4.00 (4.00) 6.00 (4.50) Physiotherapy costs (median, IQR) £ 90.00 (70.00) £ 120.00 (75.00) Physiotherapists’ training costs £200 - ABPI, active behavioural physiotherapy intervention. https://doi.org/10.1371/journal.pone.0215803.t007 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 14 / 25 Active behavioural physiotherapy intervention for acute WADII minimal clinically important difference.[104] Consequently, the sample size under cluster RCT is therefore ~190 patients. The required sample size for a definitive cluster RCT is 238 patients based on an estimation of loss to follow-up of 20%. Thus, the required number of clus- ters is ~24 physiotherapy clinics based on the cluster size = 10. Serious adverse events. No serious adverse event was reported in this trial. Blinding evaluation. The views of both participants and assessor were evaluated at 3-month follow-up with regards to the effectiveness of blinding of this trial by TW. All partici- pants who attended the face-to-face 3-month follow-up (n = 10; 6 from ABPI and 4 from stan- dard physiotherapy arms) and the assessor replied ‘don’t know’ to this question. Discussion Participant recruitment There were several factors for not reaching the targeted sample size although the trial recruit- ment period was extended to July 2016 (should have finished by May 2016 based on the early feasibility data in the protocol[37]) under the oversight of the AWIS Steering Group. The first factor was the unexpected liquidation of the private physiotherapy company initially involved in this trial. Consequently, the trial was temporarily halted from 12/12/2015 to 13/03/2016. Fortunately, an insurance company took over the private physiotherapy company and after considerable negotiation agreed to continue the trial. To ensure the fidelity of the ABPI deliv- ery after the temporary break in the trial, all physiotherapists in the ABPI arm were individu- ally retrained. Secondly, a key reason for potential participants not participating was that they did not want to travel to a different physiotherapy clinic for the assessments (2 options for clin- ics). Furthermore, although the closing time of one assessment centre was 9.00 pm on Fridays and another centre provided service on Saturdays to be flexible around work commitments, several potential participants declined due to their own work-related constraints. Thirdly, another key consideration that affected recruitment was the takeover of the clinics by one insurance company, as this meant that the other insurance companies did not want to con- tinue to refer their clients. These issues illustrate the complexities of research in the private sector. According to the CONSORT diagram (Fig 1), the substantial difference in the number of participants between the intervention arms was caused by both an inequality in the number of referrals and the declining of potential participants. In this trial, two levels of randomisation were implemented to minimise the unanticipated difference of the number of referrals between the intervention arms. Randomisation attempted to compromise the difference of the number of participants between intervention arms using 2-level cluster randomisation (large- size physiotherapy clinics were randomly divided into 2 groups first and then the smaller clin- ics were randomly allocated based on provided information). Unfortunately, the numbers of eligible and recruited participants between the intervention arms were still substantially different. Characteristics of participants and physiotherapists The median age of participants in each intervention arm was substantially different (34 (IQR = 16.00) years in the ABPI and 50.50 (IQR = 18.75) years in the standard physiotherapy). This may have been a factor that explained the differences seen descriptively in recovery between the 2 arms (ABPI 19/20 = 95%; standard physiotherapy 1/6 = 16.7%). However, one meta-analysis of prognostic factors for persistent WAD compared older and younger partici- pants and found that older age (�50–55 years old) was not a significant factor (OR = 1.00, 95% CI: 0.97 to 1.04) for the risk of persistent pain and disability.[61] Additionally, the proportion PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 15 / 25 Active behavioural physiotherapy intervention for acute WADII of males and females was different across the 2 arms (there were more males than females in the ABPI and vice versa in the standard physiotherapy). The influence of gender is supported by meta-analysis data,[61] which found that females tended to have significantly more persis- tent problems than males (OR = 1.64, 95%CI: 1.27 to 2.12). However, analysis of the odds ratio suggests that the difference in the proportions of participants with persistent symptoms between genders was low.[61] One cross-sectional study found that the duration of work experience post qualification and level of qualification positively correlated with the level of knowledge in managing musculoskeletal conditions.[105] In this trial, the characteristics of physiotherapists in both arms were similar, giving confidence in findings. Outcomes and estimation In accordance with its pilot and feasibility nature,[33] the results were descriptively reported. Key findings from this trial support that the ABPI may be an effective intervention in manag- ing patients with acute WADII to prevent chronicity. Specifically: 1] Participants in the ABPI arm experienced improved recovery compared to the standard physiotherapy arm in most outcome measures. The exception was the IES and FABQ, but owing to the substantial differ- ence of the number of participants between the intervention arms and the small total sample size, this needs to be investigated further; 2] The median of difference of the planned primary outcome measure (NDI) between baseline and 3-month follow-up reached the minimal clini- cally important difference in the ABPI arm (NDI�8),[106] whereas in the standard physio- therapy arm it did not; 3] The number of fully recovered participants at 3-month follow-up was 19/20 (95%) in the ABPI arm and 1/6 (~17%) in the standard physiotherapy arm when considering a cut off of NDI�4.[15, 57, 60, 107]. The loss to follow-up on the primary outcome in this trial was low owing to telephone fol- low-up strategy, although the majority of participants were young males who tended to drop out more than older males and females.[108] In the ABPI arm, there was no loss to follow-up whereas 2 (25%) participants in the standard physiotherapy arm were lost to follow-up. The low loss to follow up of ~7% at 3-months was less than previous trials (>16% at 6-week follow- up).[47, 109] A useful strategy for ensuring low loss to follow-up was telephone follow-up, which is valid and reliable.[99] However, a key limitation of using telephone follow-up was the lack of physical assessments and the complete range of self-reported outcome measures (owing to feasibility, validity and reliability for the assessment via telephone). In regard to the evaluation of pain intensity via telephone in future research, the numerical rating scale (NRS) (more valid verbal assessment of pain intensity via telephone than VAS) should be used as an outcome measure rather than the VAS.[110] Strengths This trial is the first investigating WAD management in the UK private insurance setting. The ABPI is a novel potentially effective intervention for the management of acute WADII bearing in mind the number of fully recovered participants (NDI� 4)[15, 57, 60, 107] at 3-month fol- low-up. The ABPI could contribute to reducing the costs of WAD management (lower num- ber of treatment sessions and reduced costs of physiotherapy management than standard physiotherapy). The findings of this trial can be considered reliable due to the high quality of the methodology used in terms of: • Conducting and reporting in accordance with the CONSORT 2010 statement: extension to cluster randomised trial[38] and also reporting in line with the CONSORT 2010 statement: extension to randomised pilot and feasibility trials.[39] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 16 / 25 Active behavioural physiotherapy intervention for acute WADII Table 8. Considerations for a future definitive trial. Objectives Criteria for success Considerations To evaluate the feasibility of procedures (e.g. The trial would be considered feasible if it was run All research procedures were feasible but the following issues randomisation, recruitment, collecting data, smoothly without serious problems or obstructions that should be considered: management and follow-up) were able to stop the study. � Randomisation ➢ No issue regarding the randomisation (i.e. no report regarding participants’ disagreement with treatment allocation). � Recruitment ➢ Ideally, double blinding should be kept in order to maintain the quality of the trial but more assessors need to be provided for every clinic in order to reduce the risk factor of journey issues (patients did not want to travel to other physiotherapy clinics) if a future trial is to be sufficiently funded. ➢ Increase the number of recruited physiotherapy clinics/ insurance companies in order to increase the recruitment rate. ➢ An increase in the number of assessors may be considered. Setting assessment centres did not work in this trial due to participants’ journey issues. It would be ideal to have an assessor in each clinic to enable the baseline assessment to take place local to each clinic prior to the first treatment session. That would then stop the patient needing to make the separate journey for the assessment or travelling to different physiotherapy clinics. � Collecting data ➢ Information for cost-effectiveness analysis should be considered in another way (set up an electronic system by collaborating with an insurance company or a physiotherapy company in order to record relevant information rather than giving a diary pocket book to participants). ➢ Collecting level of education (less than post-secondary), headache at inception and low back pain, which are the significant predictors of persistent WAD. � Management ➢ No difficulty with the management for the trial. � Follow-up ➢ Face-to-face follow-up may be an issue because participants get back to their normal life and they may not want to come to a clinic owing to their work commitments. Telephone follow-up may be an interesting option for a future trial. To evaluate recruitment rates, refusal rates and The trial would be considered feasible if Overall, the trial was feasible as: retention in the private sector in the UK • � 50% of eligible patients were recruited • 70% of eligible patients were recruited • At least 3 participants a week per intervention arm • An average of one (1.27) person was recruited per week were recruited (excluding temporary stopping of the trial). This point was an issue to modify in the future trial. An increase in the number of • � 80% of all recruited participants completed the recruited physiotherapy clinics may be an option. follow-up at 3 months • ~93% of recruited participants completed 3-month follow-up To evaluate dropout rates of participants in the The trial would be considered feasible if� 20% of all 2/8 (25%) participants were lost to follow-up at 3 months. private sector in the UK recruited participants dropped out Therefore, the overall dropout in this trial was ~7%. To estimate the required sample for a definitive The trial would be considered feasible if it was feasible to The required sample size for a cluster RCT is 238 patients using 24 trial achieve the sample size for a cluster RCT based upon physiotherapy clinics based on power = 90%, significance recruitment data level = 0.05, difference of NDI = 4 and cluster size = 10. To evaluate the feasibility of data collection for The trial would be considered feasible if the following Only 2 participants returned their diary pocket book. Another cost-effectiveness analysis components of the cost-effective analysis were collected strategy for collecting information for cost-effectiveness analysis with minimal missing data: should be considered in another way for a future trial. Setting up an • General information (e.g. current work status and electronic recording system by collaborating with an insurance salary) company or a physiotherapy company may be a good option in order to collect relevant information. • Direct medical costs • Medical costs (e.g. physiotherapy, general practice and complementary medicine) • Resource uses (e.g. diagnosis tests) • Indirect medical costs • Participant journey costs • Training costs for physiotherapists in the experimental arm WAD, whiplash-associated disorder; RCT, randomised controlled trial; NDI, neck disability index. https://doi.org/10.1371/journal.pone.0215803.t008 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 17 / 25 Active behavioural physiotherapy intervention for acute WADII • A cluster RCT to avoid treatment contamination, increasing participant adherence,[30, 38] participant blinding,[38] and logical and administrative convenience.[40] • An effective double-blind design to reduce risk of bias. • Using and training an independent assessor in all outcome measures prior to conducting the trial, leading to reliable results. • Precision and fidelity in delivering the ABPI to physiotherapy practice (e.g. setting one train- ing day and four weeks for the individual training, systematic treatment recording and ran- dom observation of physiotherapists in the ABPI arm every month). Limitations This trial was stopped by the consensus of the AWIS Steering Group (due to timescale con- straints, budget and low number of referrals), even though the trial did not reach the target sample size predominantly due to the unexpected liquidation of the private physiotherapy company. Moreover, data regarding level of education (less than post-secondary), reported headache at inception and low back pain at baseline were not collected from the participants, and have now been identified as significant predictors for persistent WAD [61]. The diary pocket book did not work with regard to collecting information for a cost-effectiveness analy- sis and requires review. The high loss to follow-up for secondary outcome measures is a key limitation, although Table 6 comparing baseline data for participants followed up versus those lost to follow-up does not demonstrate any consistent trends. Finally, the small sample size in the control group and the large disparities in age and gender of the participants between groups are key limitations. Considerations for a future definitive trial Table 8 details the a priori criteria for consideration for a future definitive trial.[37] An ade- quately powered cluster RCT was deemed feasible with minor modifications. Conclusion This is the first trial investigating WAD management in the UK private insurance setting, and highlights the challenges for future research. The findings suggest that the ABPI is feasible (with regard to procedures, sample size and modified collection of data for cost-effectiveness analysis) and valuable (higher proportion of completely recovered participants, fewer treatment sessions, and reduced physiotherapy management costs than the standard physiotherapy). The findings support the appropriateness of conducting a future definitive trial to evaluate the effec- tiveness of the ABPI for the management of acute WADII with minor modifications. Supporting information S1 Checklist. CONSORT 2010 checklist. (DOC) S1 Data. Full data set. (SAV) Acknowledgments All authors would like to thank Dr.Nicola Heneghan, Dr. Esther Williamson and Simon Smith for joining the AWIS Steering group. Physio1st LTD for supporting patient recruitment and PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 18 / 25 Active behavioural physiotherapy intervention for acute WADII provision of assessment centres. Finally, all participants and Physio 1st LTD staff for their con- tributions and support. Author Contributions Conceptualization: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Data curation: Taweewat Wiangkham, Jonathan Price, Alison Rushton. Formal analysis: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Alison Rushton. Funding acquisition: Taweewat Wiangkham. Investigation: Taweewat Wiangkham, Jonathan Price. Methodology: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Project administration: Taweewat Wiangkham. Resources: Taweewat Wiangkham. Software: Taweewat Wiangkham. Supervision: Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Validation: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Visualization: Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Writing – original draft: Taweewat Wiangkham. Writing – review & editing: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. References 1. Spitzer WO, Skovron ML, Salmi LR, Cassidy JD, Duranceau J, Suissa S, et al. Scientific monograph of the Quebec Task Force on Whiplash-Associated Disorders: redefining "whiplash" and its manage- ment. Spine. 1995; 20(8 Suppl):1s–73s. Epub 1995/04/15. PMID: 7604354. 2. Blincoe L, Miller TR, Zaloshnja E, Lawrence BA. The economic and societal impact of motor vehicle crashes, 2010 (Revised). Washington, DC: 2015. 3. Elvik MR, Ortenwall MP, Mackay MM, Pelckmans MJ, Monclus MJ, Tecl MJ, et al. Social and eco- nomic consequences of road traffic injury in Europe. Brussels, Belgium. 2007. 4. Leth-Petersen S, Rotger GP. Long-term labour-market performance of whiplash claimants. J Health Econ. 2009; 28(5):996–1011. Epub 2009/08/18. https://doi.org/10.1016/j.jhealeco.2009.06.013 PMID: 5. Jennum P, Kjellberg J, Ibsen R, Bendix T. Health, social, and economic consequences of neck inju- ries: a controlled national study evaluating societal effects on patients and their partners. Spine. 2013; 38(5):449–57. Epub 2012/12/15. https://doi.org/10.1097/BRS.0b013e3182819203 PMID: 23238487. 6. Buitenhuis J, de Jong PJ, Jaspers JP, Groothoff JW. Work disability after whiplash: a prospective cohort study. Spine. 2009; 34(3):262–7. Epub 2009/01/17. https://doi.org/10.1097/BRS. 0b013e3181913d07 PMID: 19148041. 7. Cote P, Hogg-Johnson S, Cassidy JD, Carroll L, Frank JW, Bombardier C. Early aggressive care and delayed recovery from whiplash: isolated finding or reproducible result? Arthritis Rheum. 2007; 57 (5):861–8. Epub 2007/05/29. https://doi.org/10.1002/art.22775 PMID: 17530688. 8. Chappuis G, Soltermann B. Number and cost of claims linked to minor cervical trauma in Europe: results from the comparative study by CEA, AREDOC and CEREDOC. Eur Spine J. 2008; 17 (10):1350–7. Epub 2008/08/16. https://doi.org/10.1007/s00586-008-0732-8 PMID: 18704519 mc2556470. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 19 / 25 Active behavioural physiotherapy intervention for acute WADII 9. Holm LW, Carroll LJ, Cassidy JD, Hogg-Johnson S, Cote P, Guzman J, et al. The burden and determi- nants of neck pain in whiplash-associated disorders after traffic collisions: results of the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008; 33(4 Suppl):S52–9. Epub 2008/02/07. https://doi.org/10.1097/BRS.0b013e3181643ece PMID: 18204401. 10. Mooney H. Insurance companies are reeling from the number of claims being made by people who say they have whiplash injuries2012 October 2013. http://www.csp.org.uk/frontline/article/what%E2% 80%99s-driving-rise-whiplash-injuries. 11. Hyde D. The Telegraph [Internet]. United Kingdom2013. [cited 2013]. http://www.telegraph.co.uk/ finance/personalfinance/insurance/10185382/Why-Britain-is-the-whiplash-capital-of-Europe.html. 12. Financial Services Commission of Ontario. Financial services submission to the superintendent: sub- mitted for the review of part VI of the insurance act. Canada: Financial Services Commission of Ontario; 2014. 13. Ellman L, Champion S, Dobbin J, Lumley K, McCartney J, McCartney K, et al. Cost of motor insur- ance: whiplash. In: Committee HoCT, editor. London: The Stationery Office Limited; 2013. 14. Merrick D, Stalnacke BM. Five years post whiplash injury: Symptoms and psychological factors in recovered versus non-recovered. BMC Res Notes. 2010; 3:190. Epub 2010/07/16. https://doi.org/10. 1186/1756-0500-3-190 PMID: 20626861 mc2912943. 15. Sterling M. Physiotherapy management of whiplash-associated disorders (WAD). J Physiother. 2014; 60(1):5–12. Epub 2014/05/27. https://doi.org/10.1016/j.jphys.2013.12.004 PMID: 24856935. 16. Jull GA, Sterling M, Curatolo M, Carroll L, Hodges P. Toward lessening the rate of transition of acute whiplash to a chronic disorder. Spine. 2011; 36(25 Suppl):S173–4. Epub 2011/12/30. https://doi.org/ 10.1097/BRS.0b013e31823883e6 PMID: 22101748. 17. Borsbo B, Peolsson M, Gerdle B. Catastrophizing, depression, and pain: correlation with and Influence on quality of life and health—a study of chronic whiplash-associated disorders. J Rehabil Med. 2008; 40(7):562–9. https://doi.org/10.2340/16501977-0207 PMID: 18758674 18. Borsbo B, Peolsson M, Gerdle B. The complex interplay between pain intensity, depression, anxiety and catastrophising with respect to quality of life and disability. Disabil Rehabil. 2009; 31(19):1605–13. Epub 2009/10/24. PMID: 19848559. 19. Michaleff ZA, Maher CG, Lin CW, Rebbeck T, Jull G, Latimer J, et al. Comprehensive physiotherapy exercise programme or advice for chronic whiplash (PROMISE): a pragmatic randomised controlled trial. Lancet. 2014; 384(9938):133–41. Epub 2014/04/08. https://doi.org/10.1016/S0140-6736(14) 60457-8 PMID: 24703832. 20. Sterling M, Vicenzino B, Souvlis T, Connelly LB. Dry-needling and exercise for chronic whiplash-asso- ciated disorders: a randomized single-blind placebo-controlled trial. Pain. 2015; 156(4):635–43. PMID: 25790454 21. Lamb SE, Gates S, Williams MA, Williamson EM, Mt-Isa S, Withers EJ, et al. Emergency depart- ment treatments and physiotherapy for acute whiplash: A pragmatic, two-step, randomised con- trolled trial. Lancet. 2013; 381(9866):546–56. https://doi.org/10.1016/S0140-6736(12)61304-X PMID: 23260167. 22. Wiangkham T, Duda J, Haque MS, Madi M, Rushton A. Effectiveness of conservative treatment in acute Whiplash Associated Disorder (WAD) II: a systematic review and meta-analysis of randomised controlled trials. Physiotherapy. 2015; 101, Supplement 1(0):e1623–e4. http://dx.doi.org/10.1016/j. physio.2015.03.1642. 23. Wiangkham T, Duda J, Haque S, Madi M, Rushton A. The effectiveness of conservative management for acute whiplash associated disorder (WAD) II: a systematic review and meta-analysis of rando- mised controlled trials. PLoS One. 2015; 10(7):e0133415. Epub 2015/07/22. https://doi.org/10.1371/ journal.pone.0133415 PMID: 26196127. 24. Jull G. Whiplash continues its challenge. JOSPT, Inc. JOSPT, 1033 North Fairfax Street, Suite 304, Alexandria, VA 22134–1540; 2016. 25. Sterling M. A proposed new classification system for whiplash associated disorders—implications for assessment and management. Man Ther. 2004; 9(2):60–70. Epub 2004/03/26. https://doi.org/10. 1016/j.math.2004.01.006 PMID: 15040964. 26. Williamson E, Williams MA, Gates S, Lamb SE. Risk factors for chronic disability in a cohort of patients with acute whiplash associated disorders seeking physiotherapy treatment for persisting symptoms. Physiotherapy. 2015; 101(1):34–43. Epub 2014/07/06. https://doi.org/10.1016/j.physio.2014.04.004 PMID: 24996567. 27. Craig P, Dieppe P, Macintyre S, Michie S, Nazareth I, Petticrew M. Developing and evaluating com- plex interventions: the new Medical Research Council guidance. BMJ. 2008; 337:a1655. https://doi. org/10.1136/bmj.a1655 PMID: 18824488 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 20 / 25 Active behavioural physiotherapy intervention for acute WADII 28. Wiangkham T, Duda J, Haque MS, Rushton A. Development of an active behavioural physiotherapy intervention (ABPI) for acute whiplash-associated disorder (WAD) II management: a modified Delphi study. BMJ open. 2016; 6(9):e011764. https://doi.org/10.1136/bmjopen-2016-011764 PMID: 29. Bandura A. Self-efficacy: toward a unifying theory of behavioral change. Psychol Rev. 1977; 84 (2):191. PMID: 847061 30. Siebers AG, Klinkhamer PJ, Grefte JM, Massuger LF, Vedder JE, Beijers-Broos A, et al. Comparison of liquid-based cytology with conventional cytology for detection of cervical cancer precursors: a ran- domized controlled trial. Jama. 2009; 302(16):1757–64. Epub 2009/10/29. https://doi.org/10.1001/ jama.2009.1569 PMID: 19861667. 31. Lancaster GA, Dodd S, Williamson PR. Design and analysis of pilot studies: recommendations for good practice. J Eval Clin Pract. 2004; 10(2):307–12. Epub 2004/06/11. PMID: 15189396. 32. Arain M, Campbell MJ, Cooper CL, Lancaster GA. What is a pilot or feasibility study? a review of cur- rent practice and editorial policy. BMC Med Res Methodol. 2010; 10:67. Epub 2010/07/20. https://doi. org/10.1186/1471-2288-10-67 PMID: 20637084 mc2912920. 33. Thabane L, Ma J, Chu R, Cheng J, Ismaila A, Rios LP, et al. A tutorial on pilot studies: the what, why and how. BMC Med Res Methodol. 2010; 10:1. Epub 2010/01/08. https://doi.org/10.1186/1471-2288- 10-1 PMID: 20053272 mc2824145. 34. Whitehead AL, Sully BG, Campbell MJ. Pilot and feasibility studies: is there a difference from each other and from a randomised controlled trial? Contemp Clin Trials. 2014; 38(1):130–3. Epub 2014/04/ 17. https://doi.org/10.1016/j.cct.2014.04.001 PMID: 24735841. 35. Gould AL. Planning and revising the sample size for a trial. Stat Med. 1995; 14(9–10):1039–51; dis- cussion 53–5. Epub 1995/05/15. PMID: 7569499. 36. Coffey CS, Muller KE. Properties of internal pilots with the univariate approach to repeated mea- sures. Stat Med. 2003; 22(15):2469–85. Epub 2003/07/23. https://doi.org/10.1002/sim.1466 PMID: 37. Wiangkham T, Duda J, Haque MS, Price J, Rushton A. Acute Whiplash Injury Study (AWIS): a proto- col for a cluster randomised pilot and feasibility trial of an active behavioural physiotherapy intervention in an insurance private setting. BMJ open. 2016; 6(7):e011336. https://doi.org/10.1136/bmjopen- 2016-011336 PMID: 27412105 38. Campbell MK, Piaggio G, Elbourne DR, Altman DG. Consort 2010 statement: extension to cluster ran- domised trials. BMJ. 2012; 345:e5661. Epub 2012/09/07. https://doi.org/10.1136/bmj.e5661 PMID: 39. Eldridge SM, Chan CL, Campbell MJ, Bond CM, Hopewell S, Thabane L, et al. CONSORT 2010 state- ment: extension to randomised pilot and feasibility trials. BMJ. 2016; 355. https://doi.org/10.1136/bmj. i5239 PMID: 27777223 40. Edwards SJ, Braunholtz DA, Lilford RJ, Stevens AJ. Ethical issues in the design and conduct of cluster randomised controlled trials. BMJ. 1999; 318(7195):1407–9. Epub 1999/05/20. https://doi.org/10. 1136/bmj.318.7195.1407 PMID: 10334756 mc1115783. 41. Wyatt JC, Paterson-Brown S, Johanson R, Altman DG, Bradburn MJ, Fisk NM. Randomised trial of educational visits to enhance use of systematic reviews in 25 obstetric units. BMJ. 1998; 317 (7165):1041–6. Epub 1998/10/17. https://doi.org/10.1136/bmj.317.7165.1041 PMID: 9774287 mc28686. 42. Teerenstra S, Eldridge S, Graff M, de Hoop E, Borm GF. A simple sample size formula for analysis of covariance in cluster randomized trials. Stat Med. 2012; 31(20):2169–78. https://doi.org/10.1002/sim. 5352 PMID: 22495809 43. TRACsa. Clinical guidelines for best practice management of acute and chronic whiplash associated disorders: Clinical resource guide. Adelaide: TRACsa: Trauma and Injury Rocovery; 2008. 44. Sterling M, Kenardy J. The relationship between sensory and sympathetic nervous system changes and posttraumatic stress reaction following whiplash injury—a prospective study. J Psychosom Res. 2006; 60(4):387–93. Epub 2006/04/04. https://doi.org/10.1016/j.jpsychores.2005.08.016 PMID: 45. Jull G, Kenardy J, Hendrikz J, Cohen M, Sterling M. Management of acute whiplash: A randomized controlled trial of multidisciplinary stratified treatments. Pain. 2013; 154(9):1798–806. PMID: 46. Jagnoor J, Cameron I, Harvey L, Ierano J, Nicholson K, Rebbeck T, et al. Motor Accidents Authority: Guidelines for the management of acute whiplash-associated disorders—for health preofessionals. third ed. Sydney: NSW Government; 2014. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 21 / 25 Active behavioural physiotherapy intervention for acute WADII 47. Tough EA, White AR, Richards SH, Campbell JL. Myofascial trigger point needling for whiplash asso- ciated pain—A feasibility study. Man Ther. 2010; 15(6):529–35. https://doi.org/10.1016/j.math.2010. 05.010 PMID: 20580303. 48. Rushton A, Rivett D, Carlesso L, Flynn T, Hing W, Kerry R. International framework for examination of the cervical region for potential of Cervical Arterial Dysfunction prior to Orthopaedic Manual Therapy intervention. Man Ther. 2014; 19(3):222–8. Epub 2014/01/01. https://doi.org/10.1016/j.math.2013.11. 005 PMID: 24378471. 49. Crawford JR, Khan RJK, Varley GW. Early management and outcome following soft tissue injuries of the neck—A randomised controlled trial. Injury. 2004; 35(9):891–5. https://doi.org/10.1016/j.injury. 2004.01.011 PMID: 15302243 50. Rosenfeld M, Gunnarsson R, Borenstein P. Early intervention in whiplash-associated disorders: A comparison of two treatment protocols. Spine. 2000; 25(14):1782–7. PMID: 10888946 51. Rosenfeld M, Seferiadis A, Carlsson J, Gunnarsson R. Active intervention in patients with whiplash- associated disorders improves long-term prognosis: a randomized controlled clinical trial. Spine. 2003; 28(22):2491–8. Epub 2003/11/19. https://doi.org/10.1097/01.BRS.0000090822.96814.13 PMID: 52. Richter M, Ferrari R, Otte D, Kuensebeck HW, Blauth M, Krettek C. Correlation of clinical findings, col- lision parameters, and psychological factors in the outcome of whiplash associated disorders. J Neurol Neurosurg Psychiatry. 2004; 75(5):758–64. Epub 2004/04/20. https://doi.org/10.1136/jnnp.2003. 026963 PMID: 15090574 mc1763579. 53. Lamb SE, Gates S, Underwood MR, Cooke MW, Ashby D, Szczepura A, et al. Managing Injuries of the Neck Trial (MINT): design of a randomised controlled trial of treatments for whiplash associated disorders. BMC Musculoskelet Disord. 2007; 8:7. Epub 2007/01/30. https://doi.org/10.1186/1471- 2474-8-7 PMID: 17257408 mc1802074. 54. Hoffmann TC, Glasziou PP, Boutron I, Milne R, Perera R, Moher D, et al. Better reporting of interven- tions: template for intervention description and replication (TIDieR) checklist and guide. BMJ. 2014; 348. https://doi.org/10.1136/bmj.g1687 PMID: 24609605 55. Moore A, Jackson A, Jordan J, Hammersley S, Hill J, Mercer C, et al. Clinical guidelines for the physio- therapy management of Whiplash Associated Disorder. London: Chartered Society of Physiotherapy 56. Wiangkham T. Development and evaluation of a novel intervention for rehabilitation following whiplash injury: University of Birmingham; 2017. 57. Vernon H, Mior S. The Neck Disability Index: a study of reliability and validity. J Manipulative Physiol Ther. 1991; 14(7):409–15. Epub 1991/09/01. PMID: 1834753. 58. Pietrobon R, Coeytaux RR, Carey TS, Richardson WJ, DeVellis RF. Standard scales for measure- ment of functional outcome for cervical pain or dysfunction: a systematic review. Spine. 2002; 27 (5):515–22. Epub 2002/03/07. PMID: 11880837. 59. Vernon H. The Neck Disability Index: state-of-the-art, 1991–2008. J Manipulative Physiol Ther. 2008; 31(7):491–502. Epub 2008/09/23. https://doi.org/10.1016/j.jmpt.2008.08.006 PMID: 18803999. 60. MacDermid JC, Walton DM, Avery S, Blanchard A, Etruw E, McAlpine C, et al. Measurement proper- ties of the neck disability index: a systematic review. J Orthop Sports Phys Ther. 2009; 39(5):400–17. Epub 2009/06/13. https://doi.org/10.2519/jospt.2009.2930 PMID: 19521015. 61. Walton DM, MacDermid JC, Giorgianni AA, Mascarenhas JC, West SC, Zammit CA. Risk Factors for Persistent Problems Following Acute Whiplash Injury: Update of a Systematic Review and Meta-anal- ysis. J Orthop Sports Phys Ther. 2013; 43(2):31–43. https://doi.org/10.2519/jospt.2013.4507 PMID: 62. Huskisson E. Measurement of pain. Lancet. 1974; 304(7889):1127–31. 63. Bijur PE, Silver W, Gallagher EJ. Reliability of the visual analog scale for measurement of acute pain. Acad Emerg Med. 2001; 8(12):1153–7. PMID: 11733293 64. Myles PS, Urquhart N. The linearity of the visual analogue scale in patients with severe acute pain. Anaesth Intensive Care. 2005; 33(1):54–8. Epub 2005/06/17. https://doi.org/10.1177/ 0310057X0503300108 PMID: 15957691. 65. Price DD, Patel R, Robinson ME, Staud R. Characteristics of electronic visual analogue and numerical scales for ratings of experimental pain in healthy subjects and fibromyalgia patients. Pain. 2008; 140 (1):158–66. Epub 2008/09/13. PMID: 18786761. 66. Hendriks EJ, Scholten-Peeters GG, van der Windt DA, Neeleman-van der Steen CW, Oostendorp RA, Verhagen AP. Prognostic factors for poor recovery in acute whiplash patients. Pain. 2005; 114 (3):408–16. Epub 2005/03/22. PMID: 15777866. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 22 / 25 Active behavioural physiotherapy intervention for acute WADII 67. Stovner LJ. The nosologic status of the whiplash syndrome: a critical review based on a methodologi- cal approach. Spine. 1996; 21(23):2735–46. Epub 1996/12/01. PMID: 8979319. 68. Dall’Alba PT, Sterling MM, Treleaven JM, Edwards SL, Jull GA. Cervical range of motion discriminates between asymptomatic persons and those with whiplash. Spine. 2001; 26(19):2090–4. Epub 2001/11/ 08. PMID: 11698884. 69. Kasch H, Bach FW, Jensen TS. Handicap after acute whiplash injury: a 1-year prospective study of risk factors. Neurology. 2001; 56(12):1637–43. Epub 2001/06/27. PMID: 11425927. 70. Hole DE, Cook JM, Bolton JE. Reliability and concurrent validity of two instruments for measuring cer- vical range of motion: effects of age and gender. Man Ther. 1995; 1(1):36–42. Epub 1995/11/01. https://doi.org/10.1054/math.1995.0248 PMID: 11327793. 71. Malmstrom EM, Karlberg M, Melander A, Magnusson M. Zebris versus Myrin: a comparative study between a three-dimensional ultrasound movement analysis and an inclinometer/compass method: intradevice reliability, concurrent validity, intertester comparison, intratester reliability, and intraindivi- dual variability. Spine. 2003; 28(21):E433–40. Epub 2003/11/05. https://doi.org/10.1097/01.BRS. 0000090840.45802.D4 PMID: 14595170. 72. Williams MA, McCarthy CJ, Chorti A, Cooke MW, Gates S. A systematic review of reliability and valid- ity studies of methods for measuring active and passive cervical range of motion. J Manipulative Phy- siol Ther. 2010; 33(2):138–55. Epub 2010/02/23. https://doi.org/10.1016/j.jmpt.2009.12.009 PMID: 73. Williams M, Williamson E, Gates S, Cooke M. Reproducibility of the cervical range of motion (CROM) device for individuals with sub-acute whiplash associated disorders. Eur Spine J. 2012; 21(5):872–8. https://doi.org/10.1007/s00586-011-2096-8 PMID: 22139052 74. Vanderweeen L, Oostendorp RA, Vaes P, Duquet W. Pressure algometry in manual therapy. Man Ther. 1996; 1(5):258–65. Epub 1996/12/01. https://doi.org/10.1054/math.1996.0276 PMID: 75. Sterling M, Jull G, Vicenzino B, Kenardy J. Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery. Pain. 2003; 104(3):509–17. Epub 2003/08/21. PMID: 76. Sterling M, Jull G, Vicenzino B, Kenardy J. Characterization of acute whiplash-associated disorders. Spine. 2004; 29(2):182–8. Epub 2004/01/15. https://doi.org/10.1097/01.BRS.0000105535.12598.AE PMID: 14722412. 77. Fernandez-Perez AM, Villaverde-Gutierrez C, Mora-Sanchez A, Alonso-Blanco C, Sterling M, Fernan- dez-de-Las-Penas C. Muscle trigger points, pressure pain threshold, and cervical range of motion in patients with high level of disability related to acute whiplash injury. J Orthop Sports Phys Ther. 2012; 42(7):634–41. Epub 2012/06/09. https://doi.org/10.2519/jospt.2012.4117 PMID: 22677576. 78. Stone AM, Vicenzino B, Lim EC, Sterling M. Measures of central hyperexcitability in chronic whiplash associated disorder—a systematic review and meta-analysis. Man Ther. 2013; 18(2):111–7. Epub 2012/09/06. https://doi.org/10.1016/j.math.2012.07.009 PMID: 22947552. 79. Carroll LJ, Hurwitz EL, Cote P, Hogg-Johnson S, Carragee EJ, Nordin M, et al. Research priorities and methodological implications: the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008; 33(4 Suppl):S214–20. Epub 2008/02/07. https://doi.org/ 10.1097/BRS.0b013e318164462c PMID: 18204394. 80. Kinser AM, Sands WA, Stone MH. Reliability and validity of a pressure algometer. J Strength Cond Res. 2009; 23(1):312–4. Epub 2009/01/09. PMID: 19130648. 81. Walton DM, Macdermid JC, Nielson W, Teasell RW, Chiasson M, Brown L. Reliability, standard error, and minimum detectable change of clinical pressure pain threshold testing in people with and without acute neck pain. J Orthop Sports Phys Ther. 2011; 41(9):644–50. Epub 2011/09/03. https://doi.org/ 10.2519/jospt.2011.3666 PMID: 21885906. 82. Kardouni JR, Shaffer SW, Pidcoe PE, Finucane SD, Cheatham SA, Michener LA. Immediate changes in pressure pain sensitivity after thoracic spinal manipulative therapy in patients with subacromial impingement syndrome: A randomized controlled study. Man Ther. 2015; 20(4):540–6. Epub 2015/01/ 18. https://doi.org/10.1016/j.math.2014.12.003 PMID: 25595413. 83. Walton DM, Levesque L, Payne M, Schick J. Clinical pressure pain threshold testing in neck pain: comparing protocols, responsiveness, and association with psychological variables. Phys ther. 2014; 94(6):827–37. Epub 2014/02/22. https://doi.org/10.2522/ptj.20130369 PMID: 24557645 mc4040424. 84. Sterling M, Jull G, Vicenzino B, Kenardy J, Darnell R. Physical and psychological factors predict out- come following whiplash injury. Pain. 2005; 114(1–2):141–8. Epub 2005/03/01. PMID: 15733639. 85. Buitenhuis J, de Jong PJ, Jaspers JP, Groothoff JW. Relationship between posttraumatic stress disor- der symptoms and the course of whiplash complaints. J Psychosom Res. 2006; 61(5):681–9. Epub 2006/11/07. https://doi.org/10.1016/j.jpsychores.2006.07.008 PMID: 17084147. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 23 / 25 Active behavioural physiotherapy intervention for acute WADII 86. Asmundson GJ, Katz J. Understanding pain and posttraumatic stress disorder comorbidity: do patho- logical responses to trauma alter the perception of pain? Pain. 2008; 138(2):247–9. Epub 2008/08/08. PMID: 18684567. 87. Horowitz M, Wilner N, Alvarez W. Impact of Event Scale: a measure of subjective stress. Psychosom Med. 1979; 41(3):209–18. Epub 1979/05/01. PMID: 472086. 88. Zilberg NJ, Weiss DS, Horowitz MJ. Impact of Event Scale: a cross-validation study and some empiri- cal evidence supporting a conceptual model of stress response syndromes. J Consult Clin Psychol. 1982; 50(3):407–14. Epub 1982/06/01. PMID: 7096742. 89. Sundin EC, Horowitz MJ. Impact of Event Scale: psychometric properties. Br J Psychiatry. 2002; 180:205–9. Epub 2002/03/02. PMID: 11872511. 90. Pedler A, Sterling M. Assessing fear-avoidance beliefs in patients with whiplash-associated disorders: a comparison of 2 measures. Clin J Pain. 2011; 27(6):502–7. Epub 2011/02/15. https://doi.org/10. 1097/AJP.0b013e31820d97b0 PMID: 21317772. 91. Vernon H, Guerriero R, Soave D, Kavanaugh S, Puhl A, Reinhart C. The relationship between self- rated disability, fear-avoidance beliefs, and nonorganic signs in patients with chronic whiplash-associ- ated disorder. J Manipulative Physiol Ther. 2011; 34(8):506–13. Epub 2011/10/08. https://doi.org/10. 1016/j.jmpt.2011.08.011 PMID: 21978543. 92. Kamper SJ, Maher CG, Menezes Costa Lda C, McAuley JH, Hush JM, Sterling M. Does fear of move- ment mediate the relationship between pain intensity and disability in patients following whiplash injury? A prospective longitudinal study. Pain. 2012; 153(1):113–9. Epub 2011/11/08. PMID: 93. Buitenhuis J, de Jong PJ. Fear avoidance and illness beliefs in post-traumatic neck pain. Spine. 2011; 36(25 Suppl):S238–43. Epub 2011/10/25. https://doi.org/10.1097/BRS.0b013e3182388400 PMID: 94. Cleland JA, Fritz JM, Childs JD. Psychometric properties of the Fear-Avoidance Beliefs Questionnaire and Tampa Scale of Kinesiophobia in patients with neck pain. Am J Phys Med Rehabil. 2008; 87 (2):109–17. Epub 2007/11/13. https://doi.org/10.1097/PHM.0b013e31815b61f1 PMID: 17993982. 95. Brooks R, Group E. EuroQol: the current state of play. Health Policy. 1996; 37(1):53–72. PMID: 96. Haywood KL, Garratt AM, Fitzpatrick R. Quality of life in older people: A structured review of generic self-assessed health instruments. Qual Life Res. 2005; 14(7):1651–68. https://doi.org/10.1007/ s11136-005-1743-0 PMID: 16119178 97. Rabin R, Charro Fd. EQ-SD: a measure of health status from the EuroQol Group. Ann Med. 2001; 33 (5):337–43. PMID: 11491192 98. Luo N, Li M, Chevalier J, Lloyd A, Herdman M. A comparison of the scaling properties of the English, Spanish, French, and Chinese EQ-5D descriptive systems. Qual Life Res. 2013; 22(8):2237–43. https://doi.org/10.1007/s11136-012-0342-0 PMID: 23266797 99. Hallal PC, Simoes E, Reichert FF, Azevedo MR, Ramos LR, Pratt M, et al. Validity and reliability of the telephone-administered international physical activity questionnaire in Brazil. J Phys Act Health. 2010; 7(3):402–9. Epub 2010/06/17. PMID: 20551498. 100. McPhail S, Lane P, Russell T, Brauer SG, Urry S, Jasiewicz J, et al. Telephone reliability of the Frenchay Activity Index and EQ-5D amongst older adults. Health Qual Life Outcomes. 2009; 7(1):48. https://doi.org/10.1186/1477-7525-7-48 PMID: 19476656 101. Hertzog MA. Considerations in determining sample size for pilot studies. Res Nurs Health. 2008; 31 (2):180–91. Epub 2008/01/10. https://doi.org/10.1002/nur.20247 PMID: 18183564. 102. King J, Anderson CM. Patient Safety and Physiotherapy: What Does it Mean for Your Clinical Prac- tice? Physiother Can. 2010; 62(3):172–9. Epub 2011/06/02. https://doi.org/10.3138/physio.62.3.172 PMID: 21629594. 103. Donner A, Birkett N, Buck C. Randomization by cluster. Sample size requirements and analysis. Am J Epidemiol. 1981; 114(6):906–14. Epub 1981/12/01. PMID: 7315838. 104. Hemming K, Girling AJ, Sitch AJ, Marsh J, Lilford RJ. Sample size calculations for cluster randomised controlled trials with a fixed number of clusters. BMC Med Res Methodol. 2011; 11(1):102. https://doi. org/10.1186/1471-2288-11-102 PMID: 21718530 105. Childs JD, Whitman JM, Sizer PS, Pugia ML, Flynn TW, Delitto A. A description of physical therapists’ knowledge in managing musculoskeletal conditions. BMC Musculoskelet Disord. 2005; 6(1):32. https://doi.org/10.1186/1471-2474-6-32 PMID: 15963232 106. Carreon LY, Glassman SD, Campbell MJ, Anderson PA. Neck Disability Index, short form-36 physical component summary, and pain scales for neck and arm pain: the minimum clinically important PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 24 / 25 Active behavioural physiotherapy intervention for acute WADII difference and substantial clinical benefit after cervical spine fusion. Spine J. 2010; 10(6):469–74. http://dx.doi.org/10.1016/j.spinee.2010.02.007. PMID: 20359958 107. Sterling M, Jull G, Kenardy J. Physical and psychological factors maintain long-term predictive capac- ity post-whiplash injury. Pain. 2006; 122(1–2):102–8. http://dx.doi.org/10.1016/j.pain.2006.01.014. PMID: 16527397 108. Carstensen TBW, Fink P, Oernboel E, Kasch H, Jensen TS, Frostholm L. Sick Leave within 5 Years of Whiplash Trauma Predicts Recovery: A Prospective Cohort and Register-Based Study. PLOS ONE. 2015; 10(6):e0130298. https://doi.org/10.1371/journal.pone.0130298 PMID: 26098860 109. Ask T, Strand LI, Sture Skouen J. The effect of two exercise regimes; motor control versus endurance/ strength training for patients with whiplash-associated disorders: A randomized controlled pilot study. Clin Rehabil. 2009; 23(9):812–23. https://doi.org/10.1177/0269215509335639 PMID: 19656815 110. Bijur PE, Latimer CT, Gallagher EJ. Validation of a verbally administered numerical rating scale of acute pain for use in the emergency department. Acad Emerg Med. 2003; 10(4):390–2. PMID: PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 25 / 25 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png PLoS ONE Public Library of Science (PLoS) Journal

A cluster randomised, double-blind pilot and feasibility trial of an active behavioural physiotherapy intervention for acute whiplash-associated disorder (WAD)II

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Copyright: © 2019 Wiangkham et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: All relevant data are within the paper and its Supporting Information files. Funding: The lead author (TW) would like to thank the Royal Thai Government for the scholarship to support the trial research costs. This funding had no role in any process of this trial and publication. Competing interests: The authors have declared that no competing interests exist.
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Abstract

Citation: Wiangkham T, Duda J, Haque MS, Price J, Rushton A (2019) A cluster randomised, double- Whiplash-associated disorder (WAD) causes substantial social and economic burden, with blind pilot and feasibility trial of an active �70% patients classified as WADII (neck complaint and musculoskeletal sign(s)). Effective behavioural physiotherapy intervention for acute management in the acute stage is required to prevent development of chronicity; an issue whiplash-associated disorder (WAD)II. PLoS ONE for 60% of patients. An Active Behavioural Physiotherapy Intervention (ABPI) was devel- 14(5): e0215803. https://doi.org/10.1371/journal. pone.0215803 oped to address both physical and psychological components of WAD. The ABPI is a novel complex intervention designed through a rigorous sequential multiphase project to prevent Editor: Belinda J Gabbe, Monash University, AUSTRALIA transition of acute WAD to chronicity. An external pilot and feasibility cluster randomised Received: October 24, 2017 double-blind (assessor, participants) parallel two-arm clinical trial was conducted in the UK private sector. The trial compared ABPI versus standard physiotherapy to evaluate trial pro- Accepted: March 31, 2019 cedures and feasibility of the ABPI for managing acute WADII in preparation for a future Published: May 9, 2019 definitive trial. Six private physiotherapy clinics were recruited and cluster randomised using Copyright:© 2019 Wiangkham et al. This is an a computer-generated randomisation sequence. Twenty-eight (20 ABPI, 8 standard physio- open access article distributed under the terms of therapy) participants [median age 38.00 (IQR = 21.50) years] were recruited. Data were the Creative Commons Attribution License, which permits unrestricted use, distribution, and analysed descriptively with a priori establishment of success criteria. Ninety-five percent of reproduction in any medium, provided the original participants in the ABPI arm fully recovered (Neck Disability Index�4, compared to 17% in author and source are credited. the standard physiotherapy arm); required fewer treatment sessions; and demonstrated Data Availability Statement: All relevant data are greater improvement in all outcome measures (pain intensity, Cervical Range of Motion, within the paper and its Supporting Information Pressure Pain Threshold, EuroQol-5 Dimensions) except for the Impact of Events Scale files. and Fear Avoidance Beliefs Questionnaire. The findings support the potential value of the Funding: The lead author (TW) would like to thank ABPI, and that an adequately powered definitive trial to evaluate effectiveness (clinical, the Royal Thai Government for the scholarship to cost) is feasible with minor modifications to procedures. support the trial research costs. This funding had no role in any process of this trial and publication. Competing interests: The authors have declared that no competing interests exist. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 1 / 25 Active behavioural physiotherapy intervention for acute WADII Introduction Whiplash-associated disorders (WAD) describe a range of presentations that may be seen fol- lowing whiplash injury owing to a wide variety of possible symptoms.[1] WAD is most com- monly a consequence of road traffic accidents.[1] WAD is a major public health problem, with high annual economic costs estimated as $242 billion for the USA[2] and€180 billion for Europe.[3] Paralleling increasing healthcare costs are reduced work productivity and earning capacity.[4, 5] For example in Denmark, a decline of 20–25% in employment propensity was observed in the 2 years following a whiplash injury.[4] Insurance companies have also reported an increase in whiplash related costs,[6] particularly in the UK where insurance claim costs are considerable as individuals are largely managed within the private sector by the insurance companies.[6–12] The undesirable title of the ‘whiplash capital of Europe’ has been conferred on the UK by the Association of British Insurers, with estimates that 1 in 140 individuals make claims related to whiplash injury annually.[10] A total of 450,000–580,000 whiplash claims have been reported annually from road traffic accidents in the UK,[13] with estimates for the costs of personal injury claims rising from £7 to £14 billion over a 10 year period.[10] Interest- ingly, while the costs of whiplash are increasing, the number of patients experiencing WAD is likely to be stable.[13] These socioeconomic costs are largely explained by up to 60% of individuals with WAD progressing to experience chronic pain and disability; with ~30% people experiencing mod- erate to severe levels of pain and disability.[14–16] A key consequence of chronicity is a decrease in quality of life for individuals,[17, 18] and a resulting increase in time contributed by caregivers.[4, 5] Unfortunately, approaches to both acute and chronic WAD management have demonstrated limited success.[14, 15, 19–21] Effective management in the acute stage is therefore an important challenge to prevent patients with WAD transitioning to chronicity. [19, 22–24] The classification of WAD into 5 grades of severity[1] informs clinical reasoning to target interventions to individual patients. The most common classification accounting for�70% of individuals is WADII; characterised by a neck complaint accompanied by musculoskeletal sign(s).[25, 26] Individuals with WADII classification are commonly managed by physiothera- pists, and in the UK this is usually in the private sector where patients are referred by insurance companies to private physiotherapy clinics.[10] To date, no research has investigated this com- plex private sector context for managing WAD. Therefore, evaluation of the effectiveness of acute WAD management in the private context is a research priority. Our recent rigorous systematic review[22, 23] evaluating the effectiveness of acute WADII management found that the combination of active physiotherapy and behavioural interven- tions termed ‘Active Behavioural Physiotherapy Intervention (ABPI)’, is a potentially effective strategy for the management of acute WADII and may therefore be valuable in preventing chronicity. Unfortunately, the existing evidence was insufficient to define an ABPI interven- tion. Therefore, an ABPI was developed using empirical and theoretical perspectives through a rigorous process in line with the Medical Research Council Framework of Complex Interven- tions.[27] An initial modified Delphi study using expertise from international researchers and UK physiotherapists working with WAD patients[28] defined the individual treatment tech- niques and rehabilitation content of the intervention. Social cognitive theory focusing on self- efficacy enhancement[29] provided the underlying theoretical framework to behaviour change to enable delivery of the intervention. Following development of the ABPI, it was then impor- tant to investigate the feasibility of its use in preparation for a future definitive trial. It was important for the research to focus on the private setting in the UK where most patients are managed.[30] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 2 / 25 Active behavioural physiotherapy intervention for acute WADII Aim To evaluate trial procedures and feasibility of the ABPI in managing acute WADII within the UK insurance private sector to inform the design and sample size requirements for a future definitive RCT. Primary objectives. • To evaluate the feasibility of procedures for a cluster RCT (randomisation, recruitment, data collection, trial management and follow-up)[31–34] • To evaluate recruitment rates in the private sector in the UK[32, 33] • To evaluate loss to follow-up of participants in the private sector in the UK[32, 34] Secondary objectives. • To estimate the required sample size for a clustered definitive trial[32–36] • To evaluate the feasibility of data collection for cost-effectiveness analysis[32] Methods The trial was registered (BioMed Central, ISRCTN84528320) and conducted according to a pre-defined published protocol[37] in order to minimise potential biases, and subsequent deviations were reported. Research methods and reporting were in accordance with the CON- SORT 2010 statement: extension to cluster randomised trials.[38] The trial is reported in line with the CONSORT 2010 statement: extension to randomised pilot and feasibility trials[39] (although the CONSORT statement was published after the protocol was developed). Trial design As described in detail previously[37] an external pilot and feasibility trial of a cluster rando- mised double-blind (assessor, participants), parallel two-arm design, comparing ABPI with standard physiotherapy management, was conducted to evaluate procedures and feasibility of the ABPI (with an embedded qualitative study reported elsewhere). Six private physiotherapy clinics in the West Midlands, UK were recruited. There are many advantages to cluster rando- misation in terms of administrative convenience,[40] obtaining the cooperation of investiga- tors, ethical considerations,[40] enhancing participant adherence, reducing treatment contamination,[30, 38, 40, 41] participant blinding,[38] and logistical conveniences.[40] How- ever, the required sample size in a cluster RCT is larger than a parallel design RCT.[42] In line with the published protocol,[37] 6 private physiotherapy clinics were invited to sign consent forms (cluster-level consent) prior to cluster randomisation.[38] The physiotherapy clinics were randomly allocated to either ABPI or standard physiotherapy by a computer-gen- erated randomisation sequence. Following randomisation, consecutive potential participants referred by an insurance company to the clinics, were screened and recruited by a clinical administrator by telephone to book an initial recruitment appointment. The participant infor- mation sheet and consent form were sent via email/post to give potential participants the opportunity to read it in advance of the appointment. During the appointment, the recruiting physiotherapist discussed any issues relating to the trial, afforded an opportunity to ask ques- tions, confirmed eligibility and obtained written consent (individual-level consent). After giving informed written consent, participants were assessed on all outcome measures by a blinded assessor using standardised instruments with established measurement properties. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 3 / 25 Active behavioural physiotherapy intervention for acute WADII Assessments were made at baseline (following recruitment and consent) and at 3-months post baseline (planned primary endpoint for future definitive trial, the patients with WADII who continue with symptoms and problems after 3 months were defined as chronic).[15, 43] All outcome assessments were independent from treatment sessions and treatment clinics to ensure that the assessor was blinded to treatment allocation. The assessor was a physiotherapist familiar with and trained in use of the outcome measures, and blinded to reduce potential biases. The assessor was not able to access the booking system and participants’ information, while participants did not know to which intervention arm they were allocated, to ensure that both assessor and participants were blinded. To evaluate blinding, at the end of the 3-month follow-up for each participant, the assessor was asked which intervention they thought the patient had received, and the participants were asked which intervention arm they had been allocated to. Two assessment centres central to all clinics enabled convenient attendance for participants. The participants received a text message reminder 2 days prior to the baseline assessment and 3-month follow-up appointments. As part of the consent form, participants were asked to confirm whether they would like their data removed or kept in the trial in the sit- uation that they decided to withdraw (please see online supplementary appendices for the par- ticipant information sheet and consent form in the protocol[37]). Participants were invited to provide a reason for their withdrawal. Participants Participants were recruited from the 6 UK private physiotherapy clinics. Demographic charac- teristics, including age, gender, accident history, present drugs, and information regarding WAD symptoms were collected by the recruiting physiotherapist at the baseline assessment. Participants could claim all expenditure relating their treatment sessions from their insurance company. The trial therefore reimbursed participants for journeys at baseline and 3-month fol- low-up that were additional contact points. Eligibility criteria for clusters: private physiotherapy clinics in the West Midlands region of the UK. Preliminary data had identified that each clinic had�2 patients a month presenting with acute WADII. Inclusion criteria: Participants aged between 18–70 years presenting with WADII[1] from a road traffic accident within the previous 4 weeks.[15, 23, 43–46] Exclusion criteria: Signs and symptoms of upper cervical instability[47] or cervical artery dysfunction,[48] suspected serious spinal pathology, open wounds, active inflammatory arthri- tis, tumours, infection of the skin and soft tissue, bleeding disorders or using anti-coagulant medication,[47] any current or previous treatment from any other third party, or presenting with any serious injuries from other areas of the body resulting from the accident, history of cervical surgery,[49] previously symptomatic degenerative diseases of the cervical spine within 6 months prior to the road traffic accident,[50] previous history of whiplash or other neck pain,[45] alcohol abuse,[50, 51] dementia,[50, 51] serious mental diseases,[50, 51] psychiatric diseases,[52, 53] and/or non-English speaking and reading. Eligibility criteria were consistent with the published protocol.[37] Interventions Interventions are detailed in line with the Template for Intervention Description and Replica- tion (TIDieR)[54] and trial protocol.[37] Participants in both trial arms attended for face-to- face physiotherapy sessions in a private physiotherapy clinic lasting up to 30 minutes once a week. The total number of treatment sessions varied between 6 to 8, based on the individual physiotherapist’s assessment of the patient’s problems. All physiotherapists in both intervention PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 4 / 25 Active behavioural physiotherapy intervention for acute WADII arms were registered with the UK Health and Care Professions Councils (HCPC), and pos- sessed a minimum of a Bachelor Degree in Physiotherapy and�2 years post-registration experience. Fidelity of the ABPI was assessed through the systematic collection of a summary of treatment sessions, and the random observation of sessions by the principal investigator (TW). This enabled monitoring and feedback regarding the intervention to the treating physiotherapist. Standard physiotherapy intervention. Patients were managed according to current prac- tice reflecting the recommendations provided in the clinical whiplash guidelines.[43, 46, 55] Physiotherapy interventions such as reassurance, education, manual therapy, exercise therapy and physical agents, including a home programme of exercises, were part of management depending on the physiotherapist’s decision-making for the individual patient. The treating physiotherapists selected appropriate interventions based on examination findings and clinical reasoning.[48] Active Behavioural Physiotherapy Intervention (ABPI). The ABPI was developed through the modified Delphi study[28] and social cognitive theory focusing on self-efficacy enhancement.[29] The ABPI consisted of 4 phases in terms of the promotion of understand- ing, maturity, stamina, and coping.[37] Detail of the ABPI is provided in the published trial protocol.[37] The number of treatment sessions in each phase varied depending on an individ- ual patient’s presentation and problems based on the physiotherapist’s clinical reasoning. Physiotherapists could use a range of techniques (e.g. exercise, relaxation techniques, manual therapy) as part of their ABPI multimodal intervention based on their assessment of an indi- vidual patient’s problems using their clinical reasoning. The recommendation was 1–3 visits in each phase.[56] Physiotherapists were trained to deliver the ABPI in advance of data collection. Training consisted of a group tutorial and workshop followed up with individual training sessions to enable them to tailor the intervention to individual patients with acute WADII based on the findings from the patient history and physical examination data, and their evidence- informed clinical reasoning.[48] The physiotherapists had 4 weeks to practice the skills embedded in the ABPI prior to commencement of participant recruitment. They were ran- domly observed by TW every week before recruitment commenced and every month during data collection to ensure fidelity of the novel intervention. Feedback was provided through- out the trial. Outcomes As described in detail previously,[37] a range of outcomes were assessed. Primary outcome measure. The Neck Disability Index (NDI) is a patient-reported out- come measure and a valid, reliable and responsive tool for assessing pain and disability of the neck in both acute and chronic conditions.[57–60] It is a self-administered questionnaire con- sisting of 10 sections focused on pain intensity and functional activities including personal care, lifting, reading, headache, concentration, work, driving, sleeping and recreation.[57] Each section is scored from 0 to 5, with 5 representing the greatest disability. The sum across all sections is calculated to indicate the participant’s self-reported level of disability.[57] The NDI is a robust predictor of outcome for acute WAD[61] and is recommended for monitoring patients with WAD by several clinical guidelines, including the NHS Library, New South Wales Motor Accidents Authority, British Columbia Physiotherapy Association, Royal Dutch Society for Physical Therapy and the South Australian Centre for Trauma and Injury.[43, 46, 59] Consequently, the NDI has been used as the primary outcome in several previous whiplash intervention trials.[20, 21, 45] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 5 / 25 Active behavioural physiotherapy intervention for acute WADII Secondary outcome measures Visual Analogue Scale (VAS) for pain intensity: The most common complaint from patients with WAD is pain.[9] Pain was measured using a Visual Analogue Scale (VAS) from 0mm (no pain) to 100mm (worst possible pain).[62] It is the preferred tool for assessing pain intensity, being simple, and with established high validity and reliability in evaluating acute pain.[63–65] Use of the VAS to identify initial pain intensity has been supported as an important prognostic factor for predicting poor recovery in patients presenting with acute WAD.[61, 66] Cervical Range of Motion (CROM): Decreased cervical range of motion (CROM) is a common finding in patients presenting with WADII.[67] The measure is sensitive and can discriminate between asymptomatic people and symptomatic whiplash patients,[68] and for handicap prediction from acute whiplash injury.[69] CROM was measured using the cervical range of motion device;[70] a valid and reliable device attached to the head[71–73] while the participant sits on a comfortable chair with both hips and knees flexed to 90˚. CROM measure- ments were recorded 3 times in each direction of motion. The mean of the 3 measurements was used for data analysis. Pressure Pain Threshold (PPT): Pressure pain threshold (PPT) was measured to identify the threshold of stimulating pain.[74] Patients with WAD frequently reported central hyper- excitability in both acute (�1 month)[75–77] and chronic presentations.[78] Investigation of PPT at remote pain-free muscle sites provides information on hypersensitivity that may originate from central sensitisation.[79] PPT was measured at symptomatic areas and distal pain-free areas using a digital pressure algometer; a valid and reliable instrument to detect sensitivity.[80, 81] The force was applied at a speed of 30 kPa/s[77] and participants were asked to press a button when their perceived sensation changed from pressure to pain.[77] PPT was assessed at the insertion of the levator scapulae[77] and the upper one-third of the tibialis anterior muscle[81] bilaterally 3 times, with an interval of 1 minute between each measurement.[82, 83] The mean of the 3 measurements was used for data analysis. Positions for testing were comfortable upright sitting with hip and knee flexion to 90˚ for the levator scapulae, and supine lying with the knee of the assessed side flexed to 90˚ for the tibialis anterior. Impact of Events Scale (IES): The Impact of Event Scale (IES) is a 15-item questionnaire assessing current stress and symptoms of post-traumatic stress that may contribute to a high risk of persistent symptoms.[52, 84–86] The IES possesses established reliability and validity,[87–89] and is recommended by guidelines for monitoring whiplash management. [43, 46] Fear Avoidance Beliefs Questionnaire (FABQ): It is well documented that fear avoidance beliefs and associated behaviours following whiplash injury can influence the physical disabil- ity of patients with WAD.[90–92] Patients with any dysfunctional illness beliefs need to have these addressed as part of their management to prevent development of chronicity.[93] The Fear Avoidance Beliefs Questionnaire (FABQ) is a 16-item tool with established reliability and validity for use in populations with neck pain[94]. It is focused to the assessment of a patient’s perceptions of the impact of physical activity and work on their perceived levels of pain and disability[90]. EuroQol-5 Dimensions (EQ-5D): The EQ-5D is a valid and reliable self-report quality of life [95] questionnaire.[96] It is recommended as a useful tool for measuring generic QoL in order to provide information for cost-effectiveness analysis.[97] The EQ-5D has been trans- lated into many languages.[98] In the whiplash literature, the EQ-5D has been used to provide information for cost-effectiveness analysis in one large RCT,[21] directly informing this trial. [37] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 6 / 25 Active behavioural physiotherapy intervention for acute WADII Assessment of outcome Blinded assessment of outcomes took place at baseline and at 3-months post baseline. After 3 months, the patients with WAD who continued to experience symptoms and problems were defined as chronic.[15, 43] The number of fully recovered patients at 3 months was evaluated. Participants who did not attend the 3-month follow-up assessment were contacted by tele- phone to make a new appointment. In the situation where participants could not make a new appointment, the assessor asked them to complete the NDI[99] and EQ-5D[100] via telephone interview; both outcomes have established reliability and validity via telephone. Feasibility of cost-effectiveness analysis To assess the feasibility of data collection for the planned cost-effectiveness analysis of a definitive trial, both direct and indirect medical costs were collected. Participants received a diary pocket book to enable recording of any activities related to whiplash management including: medication use, healthcare professional consultations along with any costs they incurred, days off sick, received benefits related to WAD management. General information about participants (including post code, work status and income) was collected on the first page of the diary. Physiotherapy management related costs were collected directly from the physiotherapy clinics. The training costs of physiotherapists in the experimental ABPI trial arm were recorded. Sample size Consistent with this being a pilot and feasibility trial, a power calculation was not required. [32] There is considerable debate around establishing adequate sample sizes for pilot/feasibility trials, and the planned recruitment was for 60 participants (30 in each arm) in order to provide sufficient power of parameters for designing an adequately powered definitive RCT.[101] Physiotherapy clinic data provided evidence of n = 18 eligible participants available each month across the 6 participating clinics. The recruitment rate of the trial was considered ade- quate if�50% of eligible participants were recruited. Based on these estimates, it was antici- pated that the trial duration would be 6–7 months for recruitment combined with the 3-month follow-up. Randomisation To minimise the risk of selection bias at the cluster level, Stata software version 12 with block- ing, was used to randomise the 6 private physiotherapy clinics into the 2 trial arms: standard physiotherapy intervention (n = 3 clinics) and ABPI (n = 3 clinics). The allocation was con- cealed prior to assignment, with TW the only investigator involved in the process. Cluster ran- domisation was implemented in advance of participants being recruited. Data analysis As detailed in the published protocol,[37] data were analysed and summarised using a quanti- tative synthesis to evaluate eligibility, recruitment and follow-up rates, using IBM SPSS version 22. Consistent with the pilot and feasibility nature of this trial, data were analysed descriptively at the participant level. Descriptive statistics enabled assessment of the feasibility of the ABPI for acute WADII management.[33] Participants who received other treatments from the initial randomised treatment allocation, were retained and their data were included in intention-to- treat analyses. The planned primary endpoint of the future trial is evaluation of the NDI at 3-month follow-up. The intra-cluster correlation coefficient (ICC) was also calculated in order PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 7 / 25 Active behavioural physiotherapy intervention for acute WADII to prepare information for sample size calculation within a clustered definitive trial.[38] The analysis and findings of the quantitative data were discussed by the Acute Whiplash Injury Study (AWIS) steering and data monitoring committee at key stages. A priori feasibility criteria for progressing to definitive trial were defined (see protocol [37]). Upon completion of the pilot and feasibility trial, the following decisions were possible: • Stop if the main trial is not possible or valuable • Continue but modify the protocol if the main trial is possible and valuable • Continue without modifications but monitor closely if the main trial is possible and valuable with close monitoring • Continue without modifications if the main trial is possible and valuable.[33] Trial management and monitoring The trial was managed by a Trial Management Group consisting of TW, AR, JD and SH. The Trial Steering Committee and the Data Monitoring Committee functions were combined in line with the trial’s pilot and feasibility nature into the AWIS Steering Group, consisting of TW (principal investigator), AR (chief investigator, lead supervisor, experienced trialist), SH (statistical expert), JP (physiotherapist), a WADII patient, an external member (internationally published whiplash researcher), and an independent chair. The committee met at the start of recruitment, after 3 months of recruitment, and at the completion of data collection. The prin- cipal investigator was qualified in Good Clinical Practice [an achievement from the Interna- tional Conference on Harmonisation of Good Clinical Practice (ICH GCP), certificate number: 33951-36-41796]. Adverse events For this trial, adverse events were considered as low risk as WADII is not normally a cause of serious adverse events.[19, 21] In addition, both the ABPI and standard physiotherapy inter- ventions were conservative treatments without existing reporting of serious adverse events.[19, 21] Consequently, patients were unlikely to receive any serious harm from either intervention. In general, only minor adverse events are anticipated after physiotherapy intervention, the most commonly reported being muscle soreness, which usually recovers within 1–2 days.[102] Serious adverse events This trial had a very low risk of serious adverse events in terms of patient pathology, treatment nature and treatment management as only WADII patients were recruited. Participants were evaluated by a physiotherapist prior to seeking consent to ensure that participants were accu- rately classified as WADII (and so presented only with musculoskeletal signs, with no neuro- logical signs), ensuring that patients with high severity WAD were excluded. In addition, training ensured that all physiotherapists in this trial managed the patients informed by the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT) cervical framework,[48] a clinical reasoning framework to identify the risk of adverse events regarding and cervical artery dysfunction of the neck. The definition of a serious adverse event was wors- ening symptoms within 3 days and being admitted to the hospital due to whiplash problems. In the event of a serious adverse event occurring, participants were able to continue with the trial when their symptoms were resolved. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 8 / 25 Active behavioural physiotherapy intervention for acute WADII Procedures for reporting adverse and serious adverse events All clinics were provided with an adverse event reporting form. If a participant experienced any unpleasant symptoms, they were asked to report them to their treating physiotherapist. Physiotherapists were required to report any event to TW within 24 hours, and TW was required to report to the AWIS steering committee within 24 hours. This enabled prompt anal- ysis of the event and decision-making regarding any required action. Although not antici- pated, any unexpected serious adverse events were required to be immediately reported with an immediate written form and verbal contact by the physiotherapist to TW. Subsequently, TW would report any event to the AWIS steering committee immediately. Research governance The trial maintained research governance by using the principles of the Research Governance Framework for Health and Social Care, in line with University procedures. Data management All information collected about and from the participants was kept safely from any third party to maintain participants’ privacy. All collected documents were stored in a secure place at the School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham. All elec- tronic data were confidentially stored in a password-protected computer. Data could only be accessed by leading members of the research team. All data will be securely destroyed after 10 years. Ethical and R&D considerations NHS ethical approval and R&D approval were not required as the trial sites were in the private setting, outside of the UK National Health Service. The insurance/private clinics did not require further regulatory approval. Written support for the trial was put in place by the pri- vate clinics and the insurance companies. Ethical approval was provided by the University of Birmingham Research Ethics Committee following their detailed review (ERN_15–0542). Results Participant recruitment Twenty-eight patients were recruited between 06/11/2015 and 01/07/2016 and were followed up for a 3-month period. The trial was stopped early by consensus from the AWIS Steering Group owing to timescale, budget and a reduction of the number of referrals. Two hundred and forty (136 in the ABPI arm and 104 in the standard physiotherapy arm) potential partici- pants were assessed for eligibility by the administrators. Table 1 provides the issues affecting participants’ decisions to not participate in this trial and the administrator’s decision. Reasons for patients’ ineligibility included: ‘post four weeks after road traffic accident’, ‘serious symp- tom(s) in other regions of the body besides the neck’, ‘having treatment with another clinic’, ‘history of cervical surgery’ and ‘non-English speaking’. Reasons for potential participants declining included: ‘did not want to participate’ and ‘work commitment’. Other reasons included: ‘unable to book initial assessment within four weeks’ and ‘did not want to travel to assessment centre (different physiotherapy clinic)’. Twenty-seven in the ABPI arm and 13 in the standard physiotherapy arm eligible partici- pants were booked to attend the initial assessment to confirm eligibility, provide consent and enable baseline assessment data to be collected. Seven eligible participants from the ABPI arm and 5 from the standard physiotherapy arm could subsequently not attend this initial PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 9 / 25 Active behavioural physiotherapy intervention for acute WADII Table 1. Issues affecting participants’ decision to not participate (based on administration data). Category of reasons ABPI Standard PT (n = 109) (n = 91) Reasons for ineligibility (obtained from clinical admin team) ➢ Post four weeks after road traffic accident 54 42 ➢ Serious symptoms in other regions 10 6 ➢ Having treatment with another clinic 8 4 ➢ History of cervical surgery 3 2 ➢ Non-English speaking 1 - Reasons for declining (obtained from patients by clinical admin team) ➢ Did not want to participate 10 12 ➢ Work commitments 19 22 Other reasons ➢ Unable to book initial assessment within four weeks 2 1 ➢ Did not want to travel to assessment centre (different physiotherapy clinic) 2 2 ABPI, active behavioural physiotherapy intervention; PT, physiotherapy. https://doi.org/10.1371/journal.pone.0215803.t001 appointment. Their reasons are provided in Table 2. Therefore, 28 out of 40 eligible patients with acute WADII gave their consent and were entered into the trial (20/27 (74.07%) in the ABPI arm and 8/13 (61.54%) in the standard physiotherapy arm). The CONSORT diagram (Fig 1) presents participant progression through the trial. Baseline data Characteristics of participants by intervention arm. The median age of participants was 38.00 (range 22 to 70, IQR: 21.50) years. Table 3 presents the participants’ characteristics by intervention arm at baseline. The median ages of participants in the ABPI and standard phys- iotherapy arm were 34.00 (IQR = 16.00, range: 22 to70) and 50.50 (IQR = 18.75, range: 26 to 70), respectively. More males were recruited to the ABPI arm than females (17:3), whereas there were more females than males in the standard physiotherapy arm (2:6). White British was the most common ethnic group represented in both arms. Characteristics of physiotherapists by intervention arm. Table 4 presents characteristics of physiotherapists by intervention arm. The median ages of physiotherapists in the ABPI and standard physiotherapy arms were 27 (IQR = 0, range: 23 to 31) and 28 (IQR = 0, range: 26 to 30) years, respectively. All physiotherapists in the ABPI arm were male. Two Britons qualified Table 2. Eligible patients interested in participating but unable to attend recruitment. Category of reasons ABPI arm Standard physiotherapy arm (n = 7) (n = 5) WB ML SH GB BC SC Travel issues to assessment centres 3 - - 1 1 - Work commitment - 1 2 - - 2 Booking patients would like to reschedule - - 1 - - 1 but unable to book an initial assessment within 4-week post injury ABPI, active behavioural physiotherapy intervention; WB, West Bromwich; ML, Moseley; SH, Solihull; GB, Great Barr; BC, Birmingham City; SC, Sutton Coldfield. https://doi.org/10.1371/journal.pone.0215803.t002 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 10 / 25 Active behavioural physiotherapy intervention for acute WADII Fig 1. CONSORT flow diagram (adapted from CONSORT 2010). https://doi.org/10.1371/journal.pone.0215803.g001 Table 3. Participants’ characteristics by intervention arm at baseline. Demographic category ABPI Standard physiotherapy (n = 20) (n = 8) Age (range, median (IQR)) 22 to 70, 34.00 (16.00) 26 to 70, 50.50 (18.75) Gender (male:female) 17:3 2:6 Ethnic group White (n = 9) White (n = 6) Asian (n = 7) Asian (n = 1) Chinese or other (n = 2) Chinese or other (n = 1) Black (n = 1) Mixed (n = 1) ABPI, active behavioural physiotherapy intervention. https://doi.org/10.1371/journal.pone.0215803.t003 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 11 / 25 Active behavioural physiotherapy intervention for acute WADII Table 4. Characteristics of physiotherapists by intervention arm. Categories ABPI Standard physiotherapy (n = 3) (n = 3) Age (years) Median (IQR) 27.00 (0.00) 28.00 (0.00) Range 23 to 31 26 to 30 Gender (male:female) 3:0 2:1 Ethnicity (n) British (2) British (1) Greek (1) Greek (2) Physiotherapy qualification (n) Bachelor (2) Bachelor (2) Master (1) Master (1) Physiotherapy years of experience Median (IQR) 3.00 (0.00) 3.00 (0.00) Range 2 to 4 2 to 6 ABPI, active behavioural physiotherapy intervention; IQR, interquartile range. https://doi.org/10.1371/journal.pone.0215803.t004 with bachelor degrees in physiotherapy and one Greek qualified with a master degree in advanced musculoskeletal physiotherapy delivered the ABPI. One Briton (male) and one Greek (female) qualified with bachelor degrees in physiotherapy and one Greek (male) quali- fied with a master degree in advanced musculoskeletal physiotherapy delivered the standard physiotherapy. The physiotherapists’ duration of experience post qualification was the same in both arms, with a median of three (IQR = 0, range of the ABPI arm: 2 to 4, range of the stan- dard physiotherapy: 2 to 6) years. Numbers analysed. For each group, all participants were analysed based on their original assigned intervention arms (Fig 1: CONSORT diagram). Outcomes and estimation Primary and secondary outcome measures. Primary and secondary outcome measures at baseline and 3 months are descriptively presented in Tables 5 and 6 (baseline scores of par- ticipants followed up and lost to follow-up). At 3 months, scores on the NDI, VAS (pain inten- sity), IES, FABQ, and EQ-5D total and subscales were reduced in both trial arms. The only exception was the usual activities subscale of the EQ-5D, where no difference was observed between baseline and 3-month follow-up scores in the standard physiotherapy arm. The EQ- 5D VAS scores in both trial arms were improved at 3 months compared with baseline. Simi- larly, physical assessments (all planes of CROM and PPT of the levator scapulae and tibialis anterior muscles) were improved in both intervention arms. At the 3-month follow-up by intervention arm, the NDI, VAS (pain intensity), IES, EQ-5D (total and all subscales) were reduced in the ABPI arm more than in the standard physiother- apy arm. However, the standard physiotherapy arm had a lower score in the FABQ than in the ABPI. The scores of EQ-5D VAS and physical assessments in the ABPI arm were improved more than the standard physiotherapy arm, with the exception of sagittal cervical movement. The median of difference in each outcome measure is descriptively provided in Table 5. The NDI, VAS (pain intensity) and EQ-5D total and all subscales in the ABPI arm were reduced more than the standard physiotherapy arm. Moreover, the EQ-5D VAS, CROM all directions and PPT bilaterally for both the levator scapulae and tibialis anterior muscles (except for the left tibialis anterior muscle, which exhibited greater improvement in the stan- dard physiotherapy arm than in the ABPI arm) improved more in the ABPI arm when con- trasted to the standard physiotherapy arm. However, the psychological outcome measures PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 12 / 25 Active behavioural physiotherapy intervention for acute WADII Table 5. Primary and secondary outcome measures at baseline and three-month follow-up. Outcome measures ABPI Standard physiotherapy Baseline 3-month Median of Baseline 3-month Median of (n = 20) Median difference (n = 8) Median difference Median (IQR) (IQR) (IQR) Median (IQR) (IQR) (IQR) NDI 17.50 (18.00) 1.00 (2.75) 16.50 (17.25) 21.50 (15.50) 8.00 (8.75) 6.50 (12.50) n = 20 n = 6 VAS 55.50 (29.50) 3.50 (8.25) 48.50 (37.25) 47.00 (31.25) 14.50 (14.75) 37.00 (49.75) n = 6 n = 4 IES 29.50 (31.75) 7.50 (30.50) 13.50 (22.00) 48.00 (32.25) 26.00 (49.75) 24.00 (36.50) n = 6 n = 4 FABQ 60.00 (25.00) 38.00 (19.24) 9.50 (33.00) 61.50 (22.25) 25.50 (19.75) 22.00 (31.00) n = 6 n = 4 EQ-5D Total 11.00 (5.50) 6.00 (1.75) 5.50 (4.75) 10.50 (7.00) 8.50 (4.50) 2.00 (3.00) n = 20 n = 6 EQ-5D Mobility 2.00 (2.00) 1.00 (0.00) 1.00 (1.75) 2.50 (1.75) 1.00 (1.25) 0.50 (1.25) n = 20 n = 6 EQ-5D Self-care 2.00 (1.75) 1.00 (0.00) 1.00 (1.00) 2.00 (0.75) 1.00 (1.00) 0.00 (0.25) n = 20 n = 6 EQ-5D Usual activities 3.00 (1.75) 1.00 (0.00) 1.50 (1.00) 2.00 (1.00) 2.00 (0.25) 0.00 (0.25) n = 20 n = 6 EQ-5D Pain/discomfort 3.00 (0.75) 1.00 (1.00) 2.00 (1.00) 3.00 (1.75) 2.00 (0.50) 0.00 (1.00) n = 20 n = 6 EQ-5D Anxiety/depression 2.00 (2.00) 1.00 (0.00) 1.00 (1.00) 2.50 (1.00) 1.50 (2.50) 0.00 (2.25) n = 20 n = 6 EQ-5D VAS 57.50 (32.50) 98.50 (8.00) 27.00 (24.75) 67.50 (45.50) 75.50 (34.75) -2.00 (19.00) n = 20 n = 6 CROM Flexion 22.50 (7.67) 46.50 (15.50) 27.67 (14.00) 29.00 (13.24) 47.00 (25.34) 17.34 (21.01) n = 6 n = 4 CROM Extension 22.83 (17.58) 36.50 (30.50) 21.17 (23.59) 19.83 (24.83) 46.33 (24.50) 14.83 (35.33) n = 6 n = 4 CROM Left rotation 29.67 (18.33) 54.00 (16.08) 22.00 (28.42) 40.67 (25.01) 49.67 (24.50) -1.00 (26.00) n = 6 n = 4 CROM Right rotation 30.67 (17.83) 53.34 (25.17) 32.00 (26.91) 36.34 (22.16) 45.00 (17.34) 4.34 (12.00) n = 6 n = 4 CROM Left lateral flexion 22.34 (13.33) 34.17 (8.67) 11.50 (16.58) 26.00 (12.83) 26.67 (12.67) 1.17 (13.25) n = 6 n = 4 CROM Right lateral flexion 22.67 (11.84) 36.50 (10.75) 11.17 (15.50) 22.17 (10.84) 29.34 (8.42) 6.67 (8.08) n = 6 n = 4 PPT Left levator scapulae 74.67 (71.75) 168.67 (180.66) 90.33 (110.99) 58.67 (36.66) 109.34 (71.08) 63.67 (79.67) n = 6 n = 4 PPT Right levator scapulae 71.50 (69.66) 197.17 (157.50) 121.50 (118.33) 77.17 (44.00) 134.00 (67.59) 49.67 (83.09) n = 6 n = 4 PPT Left tibialis anterior 106.17 (101.08) 223.17 (228.33) 49.84 (129.75) 103.17 (41.08) 168.00 (233.42) 72.67 (192.42) n = 6 n = 4 PPT Right tibialis anterior 90.17 (110.34) 211.84 (233.50) 101.01 (105.00) 88.50 (24.51) 163.67 (181.91) 86.00 (160.58) n = 6 n = 4 ABPI, Active Behavioural Physiotherapy Intervention; NDI, Neck Disability Index; VAS, Visual Analogue Scale; IES, Impact of Events Scale; FABQ, Fear Avoidance Belief Questionnaire; EQ-5D, EuroQol-5 Dimensions; CROM, cervical range of motion; PPT, Pressure Pain Threshold. https://doi.org/10.1371/journal.pone.0215803.t005 (IES and FABQ) were improved more in the standard physiotherapy arm than in the ABPI arm. At the 3-month post baseline follow-up, 19/20 (95%) participants in the ABPI arm were fully recovered (NDI�4). In the standard physiotherapy arm, 1/6 participants (~17%) was PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 13 / 25 Active behavioural physiotherapy intervention for acute WADII Table 6. Secondary outcome measures at baseline of followed up and lost to follow-up participants. Outcome measures ABPI Standard physiotherapy Followed up Lost to follow-up Followed up Lost to follow-up (n = 6) (n = 14) (n = 4) (n = 4) Median (IQR) Median (IQR) Median (IQR) Median (IQR) VAS 58.00 (33.00) 52.50 (32.50) 54.50 (48.00) 46.00 (46.25) IES 25.50 (26.25) 37.00 (33.50) 50.00 (13.25) 33.50 (41.25) FABQ 53.00 (30.00) 62.50 (23.25) 59.00 (29.75) 61.50 (20.00) CROM Flexion 22.33 (9.26) 23.34 (8.92) 26.17 (13.67) 29.17 (20.83) CROM Extension 18.00 (29.58) 23.33 (12.67) 28.83 (22.51) 12.67 (24.75) CROM Left rotation 29.00 (21.34) 29.67 (18.83) 45.34 (11.17) 24.67 (25.17) CROM Right rotation 16.17 (24.67) 31.84 (14.83) 41.00 (22.67) 25.00 (23.50) CROM Left lateral flexion 21.00 (20.17) 22.34 (11.67) 26.67 (3.41) 19.17 (21.00) CROM Right lateral flexion 20.33 (21.75) 22.67 (9.83) 22.17 (16.00) 22.34 (14.42) PPT Left levator scapulae 75.00 (121.84) 74.67 (68.16) 58.50 (32.92) 66.67 (64.08) PPT Right levator scapulae 69.84 (204.92) 71.50 (53.66) 79.83 (33.00) 60.17 (61.17) PPT Left tibialis anterior 124.67 (128.42) 99.67 (95.33) 102.67 (61.33) 110.67 (40.83) PPT Right tibialis anterior 110.67 (157.58) 86.17 (83.83) 81.50 (25.34) 97.17 (31.50) ABPI, Active Behavioural Physiotherapy Intervention; VAS, Visual Analogue Scale; IES, Impact of Events Scale; FABQ, Fear Avoidance Belief Questionnaire; CROM, cervical range of motion; PPT, Pressure Pain Threshold. https://doi.org/10.1371/journal.pone.0215803.t006 fully recovered. Within the subgroup of participants who provided face-to-face assessment at the 3-month follow-up, 5/6 (~83%) participants in the ABPI arm were fully recovered. In the standard physiotherapy, no (0/4) participants were fully recovered. Table 6 enables a compari- son of baseline data for participants followed up versus those lost to follow-ups. Information regarding cost-effectiveness. Table 7 provides information about the cost- effectiveness of the 2 treatment arms, and illustrates that the number of treatment sessions and physiotherapy management costs in the ABPI arm were lower than in the standard physiother- apy arm. However, the physiotherapists in the ABPI were trained to deliver the intervention, which cost approximately £200. Only 2 participants in the ABPI arm and none of the participants in the standard physio- therapy arm returned their diary pocket book, and so the data are not reported. Coefficient of intracluster correlation (ICC) and sample size calculation for a cluster RCT. The ICC was calculated using the NDI (primary outcome measure) to inform the design effect or inflation factor[103] prior to calculation of the sample size for a cluster RCT. Based on the findings of this pilot and feasibility trial (variance between clusters = 16.574, vari- ance within clusters = 25.367 + 3.116 = 28.483), ICC = 0.368, Design Effect or inflation fac- tor = 4.312 (using cluster size = 10), the required sample size for a definitive RCT is 22 patients per arm based on power = 90%, significance level = 0.05 and difference of NDI = 8 based on Table 7. Cost-effectiveness information. Categories ABPI Standard physiotherapy (n = 20) (n = 8) Treatment sessions (median, IQR) 4.00 (4.00) 6.00 (4.50) Physiotherapy costs (median, IQR) £ 90.00 (70.00) £ 120.00 (75.00) Physiotherapists’ training costs £200 - ABPI, active behavioural physiotherapy intervention. https://doi.org/10.1371/journal.pone.0215803.t007 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 14 / 25 Active behavioural physiotherapy intervention for acute WADII minimal clinically important difference.[104] Consequently, the sample size under cluster RCT is therefore ~190 patients. The required sample size for a definitive cluster RCT is 238 patients based on an estimation of loss to follow-up of 20%. Thus, the required number of clus- ters is ~24 physiotherapy clinics based on the cluster size = 10. Serious adverse events. No serious adverse event was reported in this trial. Blinding evaluation. The views of both participants and assessor were evaluated at 3-month follow-up with regards to the effectiveness of blinding of this trial by TW. All partici- pants who attended the face-to-face 3-month follow-up (n = 10; 6 from ABPI and 4 from stan- dard physiotherapy arms) and the assessor replied ‘don’t know’ to this question. Discussion Participant recruitment There were several factors for not reaching the targeted sample size although the trial recruit- ment period was extended to July 2016 (should have finished by May 2016 based on the early feasibility data in the protocol[37]) under the oversight of the AWIS Steering Group. The first factor was the unexpected liquidation of the private physiotherapy company initially involved in this trial. Consequently, the trial was temporarily halted from 12/12/2015 to 13/03/2016. Fortunately, an insurance company took over the private physiotherapy company and after considerable negotiation agreed to continue the trial. To ensure the fidelity of the ABPI deliv- ery after the temporary break in the trial, all physiotherapists in the ABPI arm were individu- ally retrained. Secondly, a key reason for potential participants not participating was that they did not want to travel to a different physiotherapy clinic for the assessments (2 options for clin- ics). Furthermore, although the closing time of one assessment centre was 9.00 pm on Fridays and another centre provided service on Saturdays to be flexible around work commitments, several potential participants declined due to their own work-related constraints. Thirdly, another key consideration that affected recruitment was the takeover of the clinics by one insurance company, as this meant that the other insurance companies did not want to con- tinue to refer their clients. These issues illustrate the complexities of research in the private sector. According to the CONSORT diagram (Fig 1), the substantial difference in the number of participants between the intervention arms was caused by both an inequality in the number of referrals and the declining of potential participants. In this trial, two levels of randomisation were implemented to minimise the unanticipated difference of the number of referrals between the intervention arms. Randomisation attempted to compromise the difference of the number of participants between intervention arms using 2-level cluster randomisation (large- size physiotherapy clinics were randomly divided into 2 groups first and then the smaller clin- ics were randomly allocated based on provided information). Unfortunately, the numbers of eligible and recruited participants between the intervention arms were still substantially different. Characteristics of participants and physiotherapists The median age of participants in each intervention arm was substantially different (34 (IQR = 16.00) years in the ABPI and 50.50 (IQR = 18.75) years in the standard physiotherapy). This may have been a factor that explained the differences seen descriptively in recovery between the 2 arms (ABPI 19/20 = 95%; standard physiotherapy 1/6 = 16.7%). However, one meta-analysis of prognostic factors for persistent WAD compared older and younger partici- pants and found that older age (�50–55 years old) was not a significant factor (OR = 1.00, 95% CI: 0.97 to 1.04) for the risk of persistent pain and disability.[61] Additionally, the proportion PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 15 / 25 Active behavioural physiotherapy intervention for acute WADII of males and females was different across the 2 arms (there were more males than females in the ABPI and vice versa in the standard physiotherapy). The influence of gender is supported by meta-analysis data,[61] which found that females tended to have significantly more persis- tent problems than males (OR = 1.64, 95%CI: 1.27 to 2.12). However, analysis of the odds ratio suggests that the difference in the proportions of participants with persistent symptoms between genders was low.[61] One cross-sectional study found that the duration of work experience post qualification and level of qualification positively correlated with the level of knowledge in managing musculoskeletal conditions.[105] In this trial, the characteristics of physiotherapists in both arms were similar, giving confidence in findings. Outcomes and estimation In accordance with its pilot and feasibility nature,[33] the results were descriptively reported. Key findings from this trial support that the ABPI may be an effective intervention in manag- ing patients with acute WADII to prevent chronicity. Specifically: 1] Participants in the ABPI arm experienced improved recovery compared to the standard physiotherapy arm in most outcome measures. The exception was the IES and FABQ, but owing to the substantial differ- ence of the number of participants between the intervention arms and the small total sample size, this needs to be investigated further; 2] The median of difference of the planned primary outcome measure (NDI) between baseline and 3-month follow-up reached the minimal clini- cally important difference in the ABPI arm (NDI�8),[106] whereas in the standard physio- therapy arm it did not; 3] The number of fully recovered participants at 3-month follow-up was 19/20 (95%) in the ABPI arm and 1/6 (~17%) in the standard physiotherapy arm when considering a cut off of NDI�4.[15, 57, 60, 107]. The loss to follow-up on the primary outcome in this trial was low owing to telephone fol- low-up strategy, although the majority of participants were young males who tended to drop out more than older males and females.[108] In the ABPI arm, there was no loss to follow-up whereas 2 (25%) participants in the standard physiotherapy arm were lost to follow-up. The low loss to follow up of ~7% at 3-months was less than previous trials (>16% at 6-week follow- up).[47, 109] A useful strategy for ensuring low loss to follow-up was telephone follow-up, which is valid and reliable.[99] However, a key limitation of using telephone follow-up was the lack of physical assessments and the complete range of self-reported outcome measures (owing to feasibility, validity and reliability for the assessment via telephone). In regard to the evaluation of pain intensity via telephone in future research, the numerical rating scale (NRS) (more valid verbal assessment of pain intensity via telephone than VAS) should be used as an outcome measure rather than the VAS.[110] Strengths This trial is the first investigating WAD management in the UK private insurance setting. The ABPI is a novel potentially effective intervention for the management of acute WADII bearing in mind the number of fully recovered participants (NDI� 4)[15, 57, 60, 107] at 3-month fol- low-up. The ABPI could contribute to reducing the costs of WAD management (lower num- ber of treatment sessions and reduced costs of physiotherapy management than standard physiotherapy). The findings of this trial can be considered reliable due to the high quality of the methodology used in terms of: • Conducting and reporting in accordance with the CONSORT 2010 statement: extension to cluster randomised trial[38] and also reporting in line with the CONSORT 2010 statement: extension to randomised pilot and feasibility trials.[39] PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 16 / 25 Active behavioural physiotherapy intervention for acute WADII Table 8. Considerations for a future definitive trial. Objectives Criteria for success Considerations To evaluate the feasibility of procedures (e.g. The trial would be considered feasible if it was run All research procedures were feasible but the following issues randomisation, recruitment, collecting data, smoothly without serious problems or obstructions that should be considered: management and follow-up) were able to stop the study. � Randomisation ➢ No issue regarding the randomisation (i.e. no report regarding participants’ disagreement with treatment allocation). � Recruitment ➢ Ideally, double blinding should be kept in order to maintain the quality of the trial but more assessors need to be provided for every clinic in order to reduce the risk factor of journey issues (patients did not want to travel to other physiotherapy clinics) if a future trial is to be sufficiently funded. ➢ Increase the number of recruited physiotherapy clinics/ insurance companies in order to increase the recruitment rate. ➢ An increase in the number of assessors may be considered. Setting assessment centres did not work in this trial due to participants’ journey issues. It would be ideal to have an assessor in each clinic to enable the baseline assessment to take place local to each clinic prior to the first treatment session. That would then stop the patient needing to make the separate journey for the assessment or travelling to different physiotherapy clinics. � Collecting data ➢ Information for cost-effectiveness analysis should be considered in another way (set up an electronic system by collaborating with an insurance company or a physiotherapy company in order to record relevant information rather than giving a diary pocket book to participants). ➢ Collecting level of education (less than post-secondary), headache at inception and low back pain, which are the significant predictors of persistent WAD. � Management ➢ No difficulty with the management for the trial. � Follow-up ➢ Face-to-face follow-up may be an issue because participants get back to their normal life and they may not want to come to a clinic owing to their work commitments. Telephone follow-up may be an interesting option for a future trial. To evaluate recruitment rates, refusal rates and The trial would be considered feasible if Overall, the trial was feasible as: retention in the private sector in the UK • � 50% of eligible patients were recruited • 70% of eligible patients were recruited • At least 3 participants a week per intervention arm • An average of one (1.27) person was recruited per week were recruited (excluding temporary stopping of the trial). This point was an issue to modify in the future trial. An increase in the number of • � 80% of all recruited participants completed the recruited physiotherapy clinics may be an option. follow-up at 3 months • ~93% of recruited participants completed 3-month follow-up To evaluate dropout rates of participants in the The trial would be considered feasible if� 20% of all 2/8 (25%) participants were lost to follow-up at 3 months. private sector in the UK recruited participants dropped out Therefore, the overall dropout in this trial was ~7%. To estimate the required sample for a definitive The trial would be considered feasible if it was feasible to The required sample size for a cluster RCT is 238 patients using 24 trial achieve the sample size for a cluster RCT based upon physiotherapy clinics based on power = 90%, significance recruitment data level = 0.05, difference of NDI = 4 and cluster size = 10. To evaluate the feasibility of data collection for The trial would be considered feasible if the following Only 2 participants returned their diary pocket book. Another cost-effectiveness analysis components of the cost-effective analysis were collected strategy for collecting information for cost-effectiveness analysis with minimal missing data: should be considered in another way for a future trial. Setting up an • General information (e.g. current work status and electronic recording system by collaborating with an insurance salary) company or a physiotherapy company may be a good option in order to collect relevant information. • Direct medical costs • Medical costs (e.g. physiotherapy, general practice and complementary medicine) • Resource uses (e.g. diagnosis tests) • Indirect medical costs • Participant journey costs • Training costs for physiotherapists in the experimental arm WAD, whiplash-associated disorder; RCT, randomised controlled trial; NDI, neck disability index. https://doi.org/10.1371/journal.pone.0215803.t008 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 17 / 25 Active behavioural physiotherapy intervention for acute WADII • A cluster RCT to avoid treatment contamination, increasing participant adherence,[30, 38] participant blinding,[38] and logical and administrative convenience.[40] • An effective double-blind design to reduce risk of bias. • Using and training an independent assessor in all outcome measures prior to conducting the trial, leading to reliable results. • Precision and fidelity in delivering the ABPI to physiotherapy practice (e.g. setting one train- ing day and four weeks for the individual training, systematic treatment recording and ran- dom observation of physiotherapists in the ABPI arm every month). Limitations This trial was stopped by the consensus of the AWIS Steering Group (due to timescale con- straints, budget and low number of referrals), even though the trial did not reach the target sample size predominantly due to the unexpected liquidation of the private physiotherapy company. Moreover, data regarding level of education (less than post-secondary), reported headache at inception and low back pain at baseline were not collected from the participants, and have now been identified as significant predictors for persistent WAD [61]. The diary pocket book did not work with regard to collecting information for a cost-effectiveness analy- sis and requires review. The high loss to follow-up for secondary outcome measures is a key limitation, although Table 6 comparing baseline data for participants followed up versus those lost to follow-up does not demonstrate any consistent trends. Finally, the small sample size in the control group and the large disparities in age and gender of the participants between groups are key limitations. Considerations for a future definitive trial Table 8 details the a priori criteria for consideration for a future definitive trial.[37] An ade- quately powered cluster RCT was deemed feasible with minor modifications. Conclusion This is the first trial investigating WAD management in the UK private insurance setting, and highlights the challenges for future research. The findings suggest that the ABPI is feasible (with regard to procedures, sample size and modified collection of data for cost-effectiveness analysis) and valuable (higher proportion of completely recovered participants, fewer treatment sessions, and reduced physiotherapy management costs than the standard physiotherapy). The findings support the appropriateness of conducting a future definitive trial to evaluate the effec- tiveness of the ABPI for the management of acute WADII with minor modifications. Supporting information S1 Checklist. CONSORT 2010 checklist. (DOC) S1 Data. Full data set. (SAV) Acknowledgments All authors would like to thank Dr.Nicola Heneghan, Dr. Esther Williamson and Simon Smith for joining the AWIS Steering group. Physio1st LTD for supporting patient recruitment and PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 18 / 25 Active behavioural physiotherapy intervention for acute WADII provision of assessment centres. Finally, all participants and Physio 1st LTD staff for their con- tributions and support. Author Contributions Conceptualization: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Data curation: Taweewat Wiangkham, Jonathan Price, Alison Rushton. Formal analysis: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Alison Rushton. Funding acquisition: Taweewat Wiangkham. Investigation: Taweewat Wiangkham, Jonathan Price. Methodology: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Project administration: Taweewat Wiangkham. Resources: Taweewat Wiangkham. Software: Taweewat Wiangkham. Supervision: Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Validation: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Visualization: Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. Writing – original draft: Taweewat Wiangkham. Writing – review & editing: Taweewat Wiangkham, Joan Duda, M. Sayeed Haque, Jonathan Price, Alison Rushton. References 1. Spitzer WO, Skovron ML, Salmi LR, Cassidy JD, Duranceau J, Suissa S, et al. Scientific monograph of the Quebec Task Force on Whiplash-Associated Disorders: redefining "whiplash" and its manage- ment. Spine. 1995; 20(8 Suppl):1s–73s. Epub 1995/04/15. PMID: 7604354. 2. Blincoe L, Miller TR, Zaloshnja E, Lawrence BA. The economic and societal impact of motor vehicle crashes, 2010 (Revised). Washington, DC: 2015. 3. Elvik MR, Ortenwall MP, Mackay MM, Pelckmans MJ, Monclus MJ, Tecl MJ, et al. Social and eco- nomic consequences of road traffic injury in Europe. Brussels, Belgium. 2007. 4. Leth-Petersen S, Rotger GP. Long-term labour-market performance of whiplash claimants. J Health Econ. 2009; 28(5):996–1011. Epub 2009/08/18. https://doi.org/10.1016/j.jhealeco.2009.06.013 PMID: 5. Jennum P, Kjellberg J, Ibsen R, Bendix T. Health, social, and economic consequences of neck inju- ries: a controlled national study evaluating societal effects on patients and their partners. Spine. 2013; 38(5):449–57. Epub 2012/12/15. https://doi.org/10.1097/BRS.0b013e3182819203 PMID: 23238487. 6. Buitenhuis J, de Jong PJ, Jaspers JP, Groothoff JW. Work disability after whiplash: a prospective cohort study. Spine. 2009; 34(3):262–7. Epub 2009/01/17. https://doi.org/10.1097/BRS. 0b013e3181913d07 PMID: 19148041. 7. Cote P, Hogg-Johnson S, Cassidy JD, Carroll L, Frank JW, Bombardier C. Early aggressive care and delayed recovery from whiplash: isolated finding or reproducible result? Arthritis Rheum. 2007; 57 (5):861–8. Epub 2007/05/29. https://doi.org/10.1002/art.22775 PMID: 17530688. 8. Chappuis G, Soltermann B. Number and cost of claims linked to minor cervical trauma in Europe: results from the comparative study by CEA, AREDOC and CEREDOC. Eur Spine J. 2008; 17 (10):1350–7. Epub 2008/08/16. https://doi.org/10.1007/s00586-008-0732-8 PMID: 18704519 mc2556470. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 19 / 25 Active behavioural physiotherapy intervention for acute WADII 9. Holm LW, Carroll LJ, Cassidy JD, Hogg-Johnson S, Cote P, Guzman J, et al. The burden and determi- nants of neck pain in whiplash-associated disorders after traffic collisions: results of the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008; 33(4 Suppl):S52–9. Epub 2008/02/07. https://doi.org/10.1097/BRS.0b013e3181643ece PMID: 18204401. 10. Mooney H. Insurance companies are reeling from the number of claims being made by people who say they have whiplash injuries2012 October 2013. http://www.csp.org.uk/frontline/article/what%E2% 80%99s-driving-rise-whiplash-injuries. 11. Hyde D. The Telegraph [Internet]. United Kingdom2013. [cited 2013]. http://www.telegraph.co.uk/ finance/personalfinance/insurance/10185382/Why-Britain-is-the-whiplash-capital-of-Europe.html. 12. Financial Services Commission of Ontario. Financial services submission to the superintendent: sub- mitted for the review of part VI of the insurance act. Canada: Financial Services Commission of Ontario; 2014. 13. Ellman L, Champion S, Dobbin J, Lumley K, McCartney J, McCartney K, et al. Cost of motor insur- ance: whiplash. In: Committee HoCT, editor. London: The Stationery Office Limited; 2013. 14. Merrick D, Stalnacke BM. Five years post whiplash injury: Symptoms and psychological factors in recovered versus non-recovered. BMC Res Notes. 2010; 3:190. Epub 2010/07/16. https://doi.org/10. 1186/1756-0500-3-190 PMID: 20626861 mc2912943. 15. Sterling M. Physiotherapy management of whiplash-associated disorders (WAD). J Physiother. 2014; 60(1):5–12. Epub 2014/05/27. https://doi.org/10.1016/j.jphys.2013.12.004 PMID: 24856935. 16. Jull GA, Sterling M, Curatolo M, Carroll L, Hodges P. Toward lessening the rate of transition of acute whiplash to a chronic disorder. Spine. 2011; 36(25 Suppl):S173–4. Epub 2011/12/30. https://doi.org/ 10.1097/BRS.0b013e31823883e6 PMID: 22101748. 17. Borsbo B, Peolsson M, Gerdle B. Catastrophizing, depression, and pain: correlation with and Influence on quality of life and health—a study of chronic whiplash-associated disorders. J Rehabil Med. 2008; 40(7):562–9. https://doi.org/10.2340/16501977-0207 PMID: 18758674 18. Borsbo B, Peolsson M, Gerdle B. The complex interplay between pain intensity, depression, anxiety and catastrophising with respect to quality of life and disability. Disabil Rehabil. 2009; 31(19):1605–13. Epub 2009/10/24. PMID: 19848559. 19. Michaleff ZA, Maher CG, Lin CW, Rebbeck T, Jull G, Latimer J, et al. Comprehensive physiotherapy exercise programme or advice for chronic whiplash (PROMISE): a pragmatic randomised controlled trial. Lancet. 2014; 384(9938):133–41. Epub 2014/04/08. https://doi.org/10.1016/S0140-6736(14) 60457-8 PMID: 24703832. 20. Sterling M, Vicenzino B, Souvlis T, Connelly LB. Dry-needling and exercise for chronic whiplash-asso- ciated disorders: a randomized single-blind placebo-controlled trial. Pain. 2015; 156(4):635–43. PMID: 25790454 21. Lamb SE, Gates S, Williams MA, Williamson EM, Mt-Isa S, Withers EJ, et al. Emergency depart- ment treatments and physiotherapy for acute whiplash: A pragmatic, two-step, randomised con- trolled trial. Lancet. 2013; 381(9866):546–56. https://doi.org/10.1016/S0140-6736(12)61304-X PMID: 23260167. 22. Wiangkham T, Duda J, Haque MS, Madi M, Rushton A. Effectiveness of conservative treatment in acute Whiplash Associated Disorder (WAD) II: a systematic review and meta-analysis of randomised controlled trials. Physiotherapy. 2015; 101, Supplement 1(0):e1623–e4. http://dx.doi.org/10.1016/j. physio.2015.03.1642. 23. Wiangkham T, Duda J, Haque S, Madi M, Rushton A. The effectiveness of conservative management for acute whiplash associated disorder (WAD) II: a systematic review and meta-analysis of rando- mised controlled trials. PLoS One. 2015; 10(7):e0133415. Epub 2015/07/22. https://doi.org/10.1371/ journal.pone.0133415 PMID: 26196127. 24. Jull G. Whiplash continues its challenge. JOSPT, Inc. JOSPT, 1033 North Fairfax Street, Suite 304, Alexandria, VA 22134–1540; 2016. 25. Sterling M. A proposed new classification system for whiplash associated disorders—implications for assessment and management. Man Ther. 2004; 9(2):60–70. Epub 2004/03/26. https://doi.org/10. 1016/j.math.2004.01.006 PMID: 15040964. 26. Williamson E, Williams MA, Gates S, Lamb SE. Risk factors for chronic disability in a cohort of patients with acute whiplash associated disorders seeking physiotherapy treatment for persisting symptoms. Physiotherapy. 2015; 101(1):34–43. Epub 2014/07/06. https://doi.org/10.1016/j.physio.2014.04.004 PMID: 24996567. 27. Craig P, Dieppe P, Macintyre S, Michie S, Nazareth I, Petticrew M. Developing and evaluating com- plex interventions: the new Medical Research Council guidance. BMJ. 2008; 337:a1655. https://doi. org/10.1136/bmj.a1655 PMID: 18824488 PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 20 / 25 Active behavioural physiotherapy intervention for acute WADII 28. Wiangkham T, Duda J, Haque MS, Rushton A. Development of an active behavioural physiotherapy intervention (ABPI) for acute whiplash-associated disorder (WAD) II management: a modified Delphi study. BMJ open. 2016; 6(9):e011764. https://doi.org/10.1136/bmjopen-2016-011764 PMID: 29. Bandura A. Self-efficacy: toward a unifying theory of behavioral change. Psychol Rev. 1977; 84 (2):191. PMID: 847061 30. Siebers AG, Klinkhamer PJ, Grefte JM, Massuger LF, Vedder JE, Beijers-Broos A, et al. Comparison of liquid-based cytology with conventional cytology for detection of cervical cancer precursors: a ran- domized controlled trial. Jama. 2009; 302(16):1757–64. Epub 2009/10/29. https://doi.org/10.1001/ jama.2009.1569 PMID: 19861667. 31. Lancaster GA, Dodd S, Williamson PR. Design and analysis of pilot studies: recommendations for good practice. J Eval Clin Pract. 2004; 10(2):307–12. Epub 2004/06/11. PMID: 15189396. 32. Arain M, Campbell MJ, Cooper CL, Lancaster GA. What is a pilot or feasibility study? a review of cur- rent practice and editorial policy. BMC Med Res Methodol. 2010; 10:67. Epub 2010/07/20. https://doi. org/10.1186/1471-2288-10-67 PMID: 20637084 mc2912920. 33. Thabane L, Ma J, Chu R, Cheng J, Ismaila A, Rios LP, et al. A tutorial on pilot studies: the what, why and how. BMC Med Res Methodol. 2010; 10:1. Epub 2010/01/08. https://doi.org/10.1186/1471-2288- 10-1 PMID: 20053272 mc2824145. 34. Whitehead AL, Sully BG, Campbell MJ. Pilot and feasibility studies: is there a difference from each other and from a randomised controlled trial? Contemp Clin Trials. 2014; 38(1):130–3. Epub 2014/04/ 17. https://doi.org/10.1016/j.cct.2014.04.001 PMID: 24735841. 35. Gould AL. Planning and revising the sample size for a trial. Stat Med. 1995; 14(9–10):1039–51; dis- cussion 53–5. Epub 1995/05/15. PMID: 7569499. 36. Coffey CS, Muller KE. Properties of internal pilots with the univariate approach to repeated mea- sures. Stat Med. 2003; 22(15):2469–85. Epub 2003/07/23. https://doi.org/10.1002/sim.1466 PMID: 37. Wiangkham T, Duda J, Haque MS, Price J, Rushton A. Acute Whiplash Injury Study (AWIS): a proto- col for a cluster randomised pilot and feasibility trial of an active behavioural physiotherapy intervention in an insurance private setting. BMJ open. 2016; 6(7):e011336. https://doi.org/10.1136/bmjopen- 2016-011336 PMID: 27412105 38. Campbell MK, Piaggio G, Elbourne DR, Altman DG. Consort 2010 statement: extension to cluster ran- domised trials. BMJ. 2012; 345:e5661. Epub 2012/09/07. https://doi.org/10.1136/bmj.e5661 PMID: 39. Eldridge SM, Chan CL, Campbell MJ, Bond CM, Hopewell S, Thabane L, et al. CONSORT 2010 state- ment: extension to randomised pilot and feasibility trials. BMJ. 2016; 355. https://doi.org/10.1136/bmj. i5239 PMID: 27777223 40. Edwards SJ, Braunholtz DA, Lilford RJ, Stevens AJ. Ethical issues in the design and conduct of cluster randomised controlled trials. BMJ. 1999; 318(7195):1407–9. Epub 1999/05/20. https://doi.org/10. 1136/bmj.318.7195.1407 PMID: 10334756 mc1115783. 41. Wyatt JC, Paterson-Brown S, Johanson R, Altman DG, Bradburn MJ, Fisk NM. Randomised trial of educational visits to enhance use of systematic reviews in 25 obstetric units. BMJ. 1998; 317 (7165):1041–6. Epub 1998/10/17. https://doi.org/10.1136/bmj.317.7165.1041 PMID: 9774287 mc28686. 42. Teerenstra S, Eldridge S, Graff M, de Hoop E, Borm GF. A simple sample size formula for analysis of covariance in cluster randomized trials. Stat Med. 2012; 31(20):2169–78. https://doi.org/10.1002/sim. 5352 PMID: 22495809 43. TRACsa. Clinical guidelines for best practice management of acute and chronic whiplash associated disorders: Clinical resource guide. Adelaide: TRACsa: Trauma and Injury Rocovery; 2008. 44. Sterling M, Kenardy J. The relationship between sensory and sympathetic nervous system changes and posttraumatic stress reaction following whiplash injury—a prospective study. J Psychosom Res. 2006; 60(4):387–93. Epub 2006/04/04. https://doi.org/10.1016/j.jpsychores.2005.08.016 PMID: 45. Jull G, Kenardy J, Hendrikz J, Cohen M, Sterling M. Management of acute whiplash: A randomized controlled trial of multidisciplinary stratified treatments. Pain. 2013; 154(9):1798–806. PMID: 46. Jagnoor J, Cameron I, Harvey L, Ierano J, Nicholson K, Rebbeck T, et al. Motor Accidents Authority: Guidelines for the management of acute whiplash-associated disorders—for health preofessionals. third ed. Sydney: NSW Government; 2014. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 21 / 25 Active behavioural physiotherapy intervention for acute WADII 47. Tough EA, White AR, Richards SH, Campbell JL. Myofascial trigger point needling for whiplash asso- ciated pain—A feasibility study. Man Ther. 2010; 15(6):529–35. https://doi.org/10.1016/j.math.2010. 05.010 PMID: 20580303. 48. Rushton A, Rivett D, Carlesso L, Flynn T, Hing W, Kerry R. International framework for examination of the cervical region for potential of Cervical Arterial Dysfunction prior to Orthopaedic Manual Therapy intervention. Man Ther. 2014; 19(3):222–8. Epub 2014/01/01. https://doi.org/10.1016/j.math.2013.11. 005 PMID: 24378471. 49. Crawford JR, Khan RJK, Varley GW. Early management and outcome following soft tissue injuries of the neck—A randomised controlled trial. Injury. 2004; 35(9):891–5. https://doi.org/10.1016/j.injury. 2004.01.011 PMID: 15302243 50. Rosenfeld M, Gunnarsson R, Borenstein P. Early intervention in whiplash-associated disorders: A comparison of two treatment protocols. Spine. 2000; 25(14):1782–7. PMID: 10888946 51. Rosenfeld M, Seferiadis A, Carlsson J, Gunnarsson R. Active intervention in patients with whiplash- associated disorders improves long-term prognosis: a randomized controlled clinical trial. Spine. 2003; 28(22):2491–8. Epub 2003/11/19. https://doi.org/10.1097/01.BRS.0000090822.96814.13 PMID: 52. Richter M, Ferrari R, Otte D, Kuensebeck HW, Blauth M, Krettek C. Correlation of clinical findings, col- lision parameters, and psychological factors in the outcome of whiplash associated disorders. J Neurol Neurosurg Psychiatry. 2004; 75(5):758–64. Epub 2004/04/20. https://doi.org/10.1136/jnnp.2003. 026963 PMID: 15090574 mc1763579. 53. Lamb SE, Gates S, Underwood MR, Cooke MW, Ashby D, Szczepura A, et al. Managing Injuries of the Neck Trial (MINT): design of a randomised controlled trial of treatments for whiplash associated disorders. BMC Musculoskelet Disord. 2007; 8:7. Epub 2007/01/30. https://doi.org/10.1186/1471- 2474-8-7 PMID: 17257408 mc1802074. 54. Hoffmann TC, Glasziou PP, Boutron I, Milne R, Perera R, Moher D, et al. Better reporting of interven- tions: template for intervention description and replication (TIDieR) checklist and guide. BMJ. 2014; 348. https://doi.org/10.1136/bmj.g1687 PMID: 24609605 55. Moore A, Jackson A, Jordan J, Hammersley S, Hill J, Mercer C, et al. Clinical guidelines for the physio- therapy management of Whiplash Associated Disorder. London: Chartered Society of Physiotherapy 56. Wiangkham T. Development and evaluation of a novel intervention for rehabilitation following whiplash injury: University of Birmingham; 2017. 57. Vernon H, Mior S. The Neck Disability Index: a study of reliability and validity. J Manipulative Physiol Ther. 1991; 14(7):409–15. Epub 1991/09/01. PMID: 1834753. 58. Pietrobon R, Coeytaux RR, Carey TS, Richardson WJ, DeVellis RF. Standard scales for measure- ment of functional outcome for cervical pain or dysfunction: a systematic review. Spine. 2002; 27 (5):515–22. Epub 2002/03/07. PMID: 11880837. 59. Vernon H. The Neck Disability Index: state-of-the-art, 1991–2008. J Manipulative Physiol Ther. 2008; 31(7):491–502. Epub 2008/09/23. https://doi.org/10.1016/j.jmpt.2008.08.006 PMID: 18803999. 60. MacDermid JC, Walton DM, Avery S, Blanchard A, Etruw E, McAlpine C, et al. Measurement proper- ties of the neck disability index: a systematic review. J Orthop Sports Phys Ther. 2009; 39(5):400–17. Epub 2009/06/13. https://doi.org/10.2519/jospt.2009.2930 PMID: 19521015. 61. Walton DM, MacDermid JC, Giorgianni AA, Mascarenhas JC, West SC, Zammit CA. Risk Factors for Persistent Problems Following Acute Whiplash Injury: Update of a Systematic Review and Meta-anal- ysis. J Orthop Sports Phys Ther. 2013; 43(2):31–43. https://doi.org/10.2519/jospt.2013.4507 PMID: 62. Huskisson E. Measurement of pain. Lancet. 1974; 304(7889):1127–31. 63. Bijur PE, Silver W, Gallagher EJ. Reliability of the visual analog scale for measurement of acute pain. Acad Emerg Med. 2001; 8(12):1153–7. PMID: 11733293 64. Myles PS, Urquhart N. The linearity of the visual analogue scale in patients with severe acute pain. Anaesth Intensive Care. 2005; 33(1):54–8. Epub 2005/06/17. https://doi.org/10.1177/ 0310057X0503300108 PMID: 15957691. 65. Price DD, Patel R, Robinson ME, Staud R. Characteristics of electronic visual analogue and numerical scales for ratings of experimental pain in healthy subjects and fibromyalgia patients. Pain. 2008; 140 (1):158–66. Epub 2008/09/13. PMID: 18786761. 66. Hendriks EJ, Scholten-Peeters GG, van der Windt DA, Neeleman-van der Steen CW, Oostendorp RA, Verhagen AP. Prognostic factors for poor recovery in acute whiplash patients. Pain. 2005; 114 (3):408–16. Epub 2005/03/22. PMID: 15777866. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 22 / 25 Active behavioural physiotherapy intervention for acute WADII 67. Stovner LJ. The nosologic status of the whiplash syndrome: a critical review based on a methodologi- cal approach. Spine. 1996; 21(23):2735–46. Epub 1996/12/01. PMID: 8979319. 68. Dall’Alba PT, Sterling MM, Treleaven JM, Edwards SL, Jull GA. Cervical range of motion discriminates between asymptomatic persons and those with whiplash. Spine. 2001; 26(19):2090–4. Epub 2001/11/ 08. PMID: 11698884. 69. Kasch H, Bach FW, Jensen TS. Handicap after acute whiplash injury: a 1-year prospective study of risk factors. Neurology. 2001; 56(12):1637–43. Epub 2001/06/27. PMID: 11425927. 70. Hole DE, Cook JM, Bolton JE. Reliability and concurrent validity of two instruments for measuring cer- vical range of motion: effects of age and gender. Man Ther. 1995; 1(1):36–42. Epub 1995/11/01. https://doi.org/10.1054/math.1995.0248 PMID: 11327793. 71. Malmstrom EM, Karlberg M, Melander A, Magnusson M. Zebris versus Myrin: a comparative study between a three-dimensional ultrasound movement analysis and an inclinometer/compass method: intradevice reliability, concurrent validity, intertester comparison, intratester reliability, and intraindivi- dual variability. Spine. 2003; 28(21):E433–40. Epub 2003/11/05. https://doi.org/10.1097/01.BRS. 0000090840.45802.D4 PMID: 14595170. 72. Williams MA, McCarthy CJ, Chorti A, Cooke MW, Gates S. A systematic review of reliability and valid- ity studies of methods for measuring active and passive cervical range of motion. J Manipulative Phy- siol Ther. 2010; 33(2):138–55. Epub 2010/02/23. https://doi.org/10.1016/j.jmpt.2009.12.009 PMID: 73. Williams M, Williamson E, Gates S, Cooke M. Reproducibility of the cervical range of motion (CROM) device for individuals with sub-acute whiplash associated disorders. Eur Spine J. 2012; 21(5):872–8. https://doi.org/10.1007/s00586-011-2096-8 PMID: 22139052 74. Vanderweeen L, Oostendorp RA, Vaes P, Duquet W. Pressure algometry in manual therapy. Man Ther. 1996; 1(5):258–65. Epub 1996/12/01. https://doi.org/10.1054/math.1996.0276 PMID: 75. Sterling M, Jull G, Vicenzino B, Kenardy J. Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery. Pain. 2003; 104(3):509–17. Epub 2003/08/21. PMID: 76. Sterling M, Jull G, Vicenzino B, Kenardy J. Characterization of acute whiplash-associated disorders. Spine. 2004; 29(2):182–8. Epub 2004/01/15. https://doi.org/10.1097/01.BRS.0000105535.12598.AE PMID: 14722412. 77. Fernandez-Perez AM, Villaverde-Gutierrez C, Mora-Sanchez A, Alonso-Blanco C, Sterling M, Fernan- dez-de-Las-Penas C. Muscle trigger points, pressure pain threshold, and cervical range of motion in patients with high level of disability related to acute whiplash injury. J Orthop Sports Phys Ther. 2012; 42(7):634–41. Epub 2012/06/09. https://doi.org/10.2519/jospt.2012.4117 PMID: 22677576. 78. Stone AM, Vicenzino B, Lim EC, Sterling M. Measures of central hyperexcitability in chronic whiplash associated disorder—a systematic review and meta-analysis. Man Ther. 2013; 18(2):111–7. Epub 2012/09/06. https://doi.org/10.1016/j.math.2012.07.009 PMID: 22947552. 79. Carroll LJ, Hurwitz EL, Cote P, Hogg-Johnson S, Carragee EJ, Nordin M, et al. Research priorities and methodological implications: the Bone and Joint Decade 2000–2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008; 33(4 Suppl):S214–20. Epub 2008/02/07. https://doi.org/ 10.1097/BRS.0b013e318164462c PMID: 18204394. 80. Kinser AM, Sands WA, Stone MH. Reliability and validity of a pressure algometer. J Strength Cond Res. 2009; 23(1):312–4. Epub 2009/01/09. PMID: 19130648. 81. Walton DM, Macdermid JC, Nielson W, Teasell RW, Chiasson M, Brown L. Reliability, standard error, and minimum detectable change of clinical pressure pain threshold testing in people with and without acute neck pain. J Orthop Sports Phys Ther. 2011; 41(9):644–50. Epub 2011/09/03. https://doi.org/ 10.2519/jospt.2011.3666 PMID: 21885906. 82. Kardouni JR, Shaffer SW, Pidcoe PE, Finucane SD, Cheatham SA, Michener LA. Immediate changes in pressure pain sensitivity after thoracic spinal manipulative therapy in patients with subacromial impingement syndrome: A randomized controlled study. Man Ther. 2015; 20(4):540–6. Epub 2015/01/ 18. https://doi.org/10.1016/j.math.2014.12.003 PMID: 25595413. 83. Walton DM, Levesque L, Payne M, Schick J. Clinical pressure pain threshold testing in neck pain: comparing protocols, responsiveness, and association with psychological variables. Phys ther. 2014; 94(6):827–37. Epub 2014/02/22. https://doi.org/10.2522/ptj.20130369 PMID: 24557645 mc4040424. 84. Sterling M, Jull G, Vicenzino B, Kenardy J, Darnell R. Physical and psychological factors predict out- come following whiplash injury. Pain. 2005; 114(1–2):141–8. Epub 2005/03/01. PMID: 15733639. 85. Buitenhuis J, de Jong PJ, Jaspers JP, Groothoff JW. Relationship between posttraumatic stress disor- der symptoms and the course of whiplash complaints. J Psychosom Res. 2006; 61(5):681–9. Epub 2006/11/07. https://doi.org/10.1016/j.jpsychores.2006.07.008 PMID: 17084147. PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 23 / 25 Active behavioural physiotherapy intervention for acute WADII 86. Asmundson GJ, Katz J. Understanding pain and posttraumatic stress disorder comorbidity: do patho- logical responses to trauma alter the perception of pain? Pain. 2008; 138(2):247–9. Epub 2008/08/08. PMID: 18684567. 87. Horowitz M, Wilner N, Alvarez W. Impact of Event Scale: a measure of subjective stress. Psychosom Med. 1979; 41(3):209–18. Epub 1979/05/01. PMID: 472086. 88. Zilberg NJ, Weiss DS, Horowitz MJ. Impact of Event Scale: a cross-validation study and some empiri- cal evidence supporting a conceptual model of stress response syndromes. J Consult Clin Psychol. 1982; 50(3):407–14. Epub 1982/06/01. PMID: 7096742. 89. Sundin EC, Horowitz MJ. Impact of Event Scale: psychometric properties. Br J Psychiatry. 2002; 180:205–9. Epub 2002/03/02. PMID: 11872511. 90. Pedler A, Sterling M. Assessing fear-avoidance beliefs in patients with whiplash-associated disorders: a comparison of 2 measures. Clin J Pain. 2011; 27(6):502–7. Epub 2011/02/15. https://doi.org/10. 1097/AJP.0b013e31820d97b0 PMID: 21317772. 91. Vernon H, Guerriero R, Soave D, Kavanaugh S, Puhl A, Reinhart C. The relationship between self- rated disability, fear-avoidance beliefs, and nonorganic signs in patients with chronic whiplash-associ- ated disorder. J Manipulative Physiol Ther. 2011; 34(8):506–13. Epub 2011/10/08. https://doi.org/10. 1016/j.jmpt.2011.08.011 PMID: 21978543. 92. Kamper SJ, Maher CG, Menezes Costa Lda C, McAuley JH, Hush JM, Sterling M. Does fear of move- ment mediate the relationship between pain intensity and disability in patients following whiplash injury? A prospective longitudinal study. Pain. 2012; 153(1):113–9. Epub 2011/11/08. PMID: 93. Buitenhuis J, de Jong PJ. Fear avoidance and illness beliefs in post-traumatic neck pain. Spine. 2011; 36(25 Suppl):S238–43. Epub 2011/10/25. https://doi.org/10.1097/BRS.0b013e3182388400 PMID: 94. Cleland JA, Fritz JM, Childs JD. Psychometric properties of the Fear-Avoidance Beliefs Questionnaire and Tampa Scale of Kinesiophobia in patients with neck pain. Am J Phys Med Rehabil. 2008; 87 (2):109–17. Epub 2007/11/13. https://doi.org/10.1097/PHM.0b013e31815b61f1 PMID: 17993982. 95. Brooks R, Group E. EuroQol: the current state of play. Health Policy. 1996; 37(1):53–72. PMID: 96. Haywood KL, Garratt AM, Fitzpatrick R. Quality of life in older people: A structured review of generic self-assessed health instruments. Qual Life Res. 2005; 14(7):1651–68. https://doi.org/10.1007/ s11136-005-1743-0 PMID: 16119178 97. Rabin R, Charro Fd. EQ-SD: a measure of health status from the EuroQol Group. Ann Med. 2001; 33 (5):337–43. PMID: 11491192 98. Luo N, Li M, Chevalier J, Lloyd A, Herdman M. A comparison of the scaling properties of the English, Spanish, French, and Chinese EQ-5D descriptive systems. Qual Life Res. 2013; 22(8):2237–43. https://doi.org/10.1007/s11136-012-0342-0 PMID: 23266797 99. Hallal PC, Simoes E, Reichert FF, Azevedo MR, Ramos LR, Pratt M, et al. Validity and reliability of the telephone-administered international physical activity questionnaire in Brazil. J Phys Act Health. 2010; 7(3):402–9. Epub 2010/06/17. PMID: 20551498. 100. McPhail S, Lane P, Russell T, Brauer SG, Urry S, Jasiewicz J, et al. Telephone reliability of the Frenchay Activity Index and EQ-5D amongst older adults. Health Qual Life Outcomes. 2009; 7(1):48. https://doi.org/10.1186/1477-7525-7-48 PMID: 19476656 101. Hertzog MA. Considerations in determining sample size for pilot studies. Res Nurs Health. 2008; 31 (2):180–91. Epub 2008/01/10. https://doi.org/10.1002/nur.20247 PMID: 18183564. 102. King J, Anderson CM. Patient Safety and Physiotherapy: What Does it Mean for Your Clinical Prac- tice? Physiother Can. 2010; 62(3):172–9. Epub 2011/06/02. https://doi.org/10.3138/physio.62.3.172 PMID: 21629594. 103. Donner A, Birkett N, Buck C. Randomization by cluster. Sample size requirements and analysis. Am J Epidemiol. 1981; 114(6):906–14. Epub 1981/12/01. PMID: 7315838. 104. Hemming K, Girling AJ, Sitch AJ, Marsh J, Lilford RJ. Sample size calculations for cluster randomised controlled trials with a fixed number of clusters. BMC Med Res Methodol. 2011; 11(1):102. https://doi. org/10.1186/1471-2288-11-102 PMID: 21718530 105. Childs JD, Whitman JM, Sizer PS, Pugia ML, Flynn TW, Delitto A. A description of physical therapists’ knowledge in managing musculoskeletal conditions. BMC Musculoskelet Disord. 2005; 6(1):32. https://doi.org/10.1186/1471-2474-6-32 PMID: 15963232 106. Carreon LY, Glassman SD, Campbell MJ, Anderson PA. Neck Disability Index, short form-36 physical component summary, and pain scales for neck and arm pain: the minimum clinically important PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 24 / 25 Active behavioural physiotherapy intervention for acute WADII difference and substantial clinical benefit after cervical spine fusion. Spine J. 2010; 10(6):469–74. http://dx.doi.org/10.1016/j.spinee.2010.02.007. PMID: 20359958 107. Sterling M, Jull G, Kenardy J. Physical and psychological factors maintain long-term predictive capac- ity post-whiplash injury. Pain. 2006; 122(1–2):102–8. http://dx.doi.org/10.1016/j.pain.2006.01.014. PMID: 16527397 108. Carstensen TBW, Fink P, Oernboel E, Kasch H, Jensen TS, Frostholm L. Sick Leave within 5 Years of Whiplash Trauma Predicts Recovery: A Prospective Cohort and Register-Based Study. PLOS ONE. 2015; 10(6):e0130298. https://doi.org/10.1371/journal.pone.0130298 PMID: 26098860 109. Ask T, Strand LI, Sture Skouen J. The effect of two exercise regimes; motor control versus endurance/ strength training for patients with whiplash-associated disorders: A randomized controlled pilot study. Clin Rehabil. 2009; 23(9):812–23. https://doi.org/10.1177/0269215509335639 PMID: 19656815 110. Bijur PE, Latimer CT, Gallagher EJ. Validation of a verbally administered numerical rating scale of acute pain for use in the emergency department. Acad Emerg Med. 2003; 10(4):390–2. PMID: PLOS ONE | https://doi.org/10.1371/journal.pone.0215803 May 9, 2019 25 / 25

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