TY - JOUR
AU1 - Walter, C J
AU2 - Dumville, J C
AU3 - Sharp, C A
AU4 - Page, T
AB - Abstract Background Postoperative surgical-site infections are a major source of morbidity and cost. This study aimed to identify and present all randomized controlled trial evidence evaluating the effects of dressings on surgical-site infection rates in surgical wounds healing by primary intention; the secondary outcomes included comparisons of pain, scar and acceptability between dressings. Methods Randomized controlled trials comparing alternative wound dressings, or wound dressings with leaving wounds exposed for postoperative management of surgical wounds were included in the review regardless of their language. Databases searched included the Cochrane Wounds Group Specialised Register and Central Register of Controlled Trials, Ovid MEDLINE, Ovid Embase and EBSCO CINAHL from inception to May 2011. Two authors performed study selection, risk of bias assessment and data extraction, including an assessment of surgical contamination according to the surgical procedure. Where levels of clinical and statistical heterogeneity permitted, data were pooled for meta-analysis. Results Sixteen controlled trials with 2594 participants examining a range of wound contamination levels were included. They were all unclear or at high risk of bias. There was no evidence that any dressing significantly reduced surgical-site infection rates compared with any other dressing or leaving the wound exposed. Furthermore, no significant differences in pain, scarring or acceptability were seen between the dressings. Conclusion No difference in surgical-site infection rates was demonstrated between surgical wounds covered with different dressings and those left uncovered. No difference was seen in pain, scar or acceptability between dressings. Introduction An estimated 234 million surgical operations are performed worldwide every year, with the majority resulting in a wound that heals by primary intention1. Significant morbidity can result if these wounds become infected. Not only does surgical-site infection (SSI) impact on a patient's recovery, it can also lead to increased hospital stay2. With total rates of SSI in the developed world estimated at around 5 per cent, SSI is a common and expensive healthcare problem3,4. Although various patient factors, such as diabetes and steroid use, increase the likelihood of SSI, the type of surgical procedure and level of wound contamination also have a major influence4,5 (Table 1). Surgical procedures classified as clean have lower infection rates than those classified as dirty, where infection rates are as high as 30 per cent6. Table 1 Classification of wound contamination5 Level of contamination . Description . Clean Non-infective operative wounds in which no inflammation is encountered, and neither the respiratory, alimentary or genitourinary tract nor the oropharyngeal cavity is entered Clean-contaminated Operative wounds in which respiratory, alimentary, genital or urinary tract is entered under controlled conditions and without unusual contamination. Specifically, operations involving the biliary tract, appendix, vagina and oropharynx are included in this category, provided no evidence of infection or a major break in sterile technique is encountered Contaminated Fresh, accidental wounds, operations with major breaks in sterile technique or gross spillage from the gastrointestinal tract, and incisions in which acute, non-purulent inflammation is encountered Dirty Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. This definition suggests that organisms causing postoperative infection were present in the operative field before the operation Level of contamination . Description . Clean Non-infective operative wounds in which no inflammation is encountered, and neither the respiratory, alimentary or genitourinary tract nor the oropharyngeal cavity is entered Clean-contaminated Operative wounds in which respiratory, alimentary, genital or urinary tract is entered under controlled conditions and without unusual contamination. Specifically, operations involving the biliary tract, appendix, vagina and oropharynx are included in this category, provided no evidence of infection or a major break in sterile technique is encountered Contaminated Fresh, accidental wounds, operations with major breaks in sterile technique or gross spillage from the gastrointestinal tract, and incisions in which acute, non-purulent inflammation is encountered Dirty Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. This definition suggests that organisms causing postoperative infection were present in the operative field before the operation Open in new tab Table 1 Classification of wound contamination5 Level of contamination . Description . Clean Non-infective operative wounds in which no inflammation is encountered, and neither the respiratory, alimentary or genitourinary tract nor the oropharyngeal cavity is entered Clean-contaminated Operative wounds in which respiratory, alimentary, genital or urinary tract is entered under controlled conditions and without unusual contamination. Specifically, operations involving the biliary tract, appendix, vagina and oropharynx are included in this category, provided no evidence of infection or a major break in sterile technique is encountered Contaminated Fresh, accidental wounds, operations with major breaks in sterile technique or gross spillage from the gastrointestinal tract, and incisions in which acute, non-purulent inflammation is encountered Dirty Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. This definition suggests that organisms causing postoperative infection were present in the operative field before the operation Level of contamination . Description . Clean Non-infective operative wounds in which no inflammation is encountered, and neither the respiratory, alimentary or genitourinary tract nor the oropharyngeal cavity is entered Clean-contaminated Operative wounds in which respiratory, alimentary, genital or urinary tract is entered under controlled conditions and without unusual contamination. Specifically, operations involving the biliary tract, appendix, vagina and oropharynx are included in this category, provided no evidence of infection or a major break in sterile technique is encountered Contaminated Fresh, accidental wounds, operations with major breaks in sterile technique or gross spillage from the gastrointestinal tract, and incisions in which acute, non-purulent inflammation is encountered Dirty Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. This definition suggests that organisms causing postoperative infection were present in the operative field before the operation Open in new tab The common practice of dressing a surgical wound at the end of an operation assumes that by providing a barrier from environmental contamination the risk of SSI is reduced. In addition to preventing infection, dressing use may be justified by additional potential benefits such as managing wound exudate, offering physical protection, facilitating wound observation and meeting patients' desires for wound coverage. A large number of wound dressing products are currently available (Table 2; categorized according to their British National Formulary (BNF) listing7). To date, there is limited evidence to support their role in SSI prevention (Fig. 1). Fig. 1 Open in new tabDownload slide Rhomboid flap for pilonidal disease: what is the best dressing? Table 2 Summary of dressing types according to their British National Formulary listing7 Dressing type . Description . Basic wound contact dressings  Low-adherence dressings and wound contact materials Usually cotton pads which are placed directly in contact with the wound. Can be either non-medicated (e.g. paraffin gauze dressing) or medicated (e.g. containing povidone–iodine or chlorhexidine)  Absorbent dressings Applied directly to the wound and may be used as secondary absorbent layers in the management of heavily exuding wounds Advanced wound dressings  Alginate dressings Highly absorbent; come in the form of calcium alginate or calcium sodium alginate and can be combined with collagen. The alginate forms a gel when in contact with the wound surface that can be lifted off with dressing removal or rinsed away with sterile saline  Hydrogel dressings Consist of an insoluble polymer and up to 96% water. Can absorb wound exudate or rehydrate a wound, depending on the wound moisture levels. Supplied as flat sheets, as an amorphous hydrogel or as beads  Films—permeable film and membrane dressings Permeable to water vapour and oxygen but not to water or microorganisms  Soft polymer dressings Composed of a soft silicone polymer held in a non-adherent layer. Moderately absorbent  Hydrocolloid dressings Occlusive dressing, usually composed of a hydrocolloid matrix on a vapour-permeable film or foam backing  Fibrous hydrocolloid dressing Fibrous hydrocolloids have been developed that resemble alginates and are not occlusive  Foam dressings Contain hydrophilic polyurethane foam; designed to absorb wound exudate and maintain moist wound surface  Capillary-action dressings Consist of an absorbent core of hydrophilic fibres held between two low-adherent contact layers  Odour-absorbent dressings Contain charcoal and used to absorb wound odour. Can be used in conjunction with a secondary dressing to improve absorbency Antimicrobial dressings  Iodine-impregnated dressings Release free iodine when exposed to wound exudate; iodine is thought to act as a wound antiseptic  Silver-impregnated dressings Used to treat infected wounds as silver ions are thought to have antimicrobial properties. Silver versions of most dressing types are available (e.g. silver foam, silver hydrocolloid)  Other antimicrobial dressings Composed of gauze or low-adherent dressing impregnated with ointment thought to have antimicrobial properties Specialist dressings  Protease-modulating matrix dressings Proposed to alter the activity of proteolytic enzymes in chronic wounds Dressing type . Description . Basic wound contact dressings  Low-adherence dressings and wound contact materials Usually cotton pads which are placed directly in contact with the wound. Can be either non-medicated (e.g. paraffin gauze dressing) or medicated (e.g. containing povidone–iodine or chlorhexidine)  Absorbent dressings Applied directly to the wound and may be used as secondary absorbent layers in the management of heavily exuding wounds Advanced wound dressings  Alginate dressings Highly absorbent; come in the form of calcium alginate or calcium sodium alginate and can be combined with collagen. The alginate forms a gel when in contact with the wound surface that can be lifted off with dressing removal or rinsed away with sterile saline  Hydrogel dressings Consist of an insoluble polymer and up to 96% water. Can absorb wound exudate or rehydrate a wound, depending on the wound moisture levels. Supplied as flat sheets, as an amorphous hydrogel or as beads  Films—permeable film and membrane dressings Permeable to water vapour and oxygen but not to water or microorganisms  Soft polymer dressings Composed of a soft silicone polymer held in a non-adherent layer. Moderately absorbent  Hydrocolloid dressings Occlusive dressing, usually composed of a hydrocolloid matrix on a vapour-permeable film or foam backing  Fibrous hydrocolloid dressing Fibrous hydrocolloids have been developed that resemble alginates and are not occlusive  Foam dressings Contain hydrophilic polyurethane foam; designed to absorb wound exudate and maintain moist wound surface  Capillary-action dressings Consist of an absorbent core of hydrophilic fibres held between two low-adherent contact layers  Odour-absorbent dressings Contain charcoal and used to absorb wound odour. Can be used in conjunction with a secondary dressing to improve absorbency Antimicrobial dressings  Iodine-impregnated dressings Release free iodine when exposed to wound exudate; iodine is thought to act as a wound antiseptic  Silver-impregnated dressings Used to treat infected wounds as silver ions are thought to have antimicrobial properties. Silver versions of most dressing types are available (e.g. silver foam, silver hydrocolloid)  Other antimicrobial dressings Composed of gauze or low-adherent dressing impregnated with ointment thought to have antimicrobial properties Specialist dressings  Protease-modulating matrix dressings Proposed to alter the activity of proteolytic enzymes in chronic wounds Open in new tab Table 2 Summary of dressing types according to their British National Formulary listing7 Dressing type . Description . Basic wound contact dressings  Low-adherence dressings and wound contact materials Usually cotton pads which are placed directly in contact with the wound. Can be either non-medicated (e.g. paraffin gauze dressing) or medicated (e.g. containing povidone–iodine or chlorhexidine)  Absorbent dressings Applied directly to the wound and may be used as secondary absorbent layers in the management of heavily exuding wounds Advanced wound dressings  Alginate dressings Highly absorbent; come in the form of calcium alginate or calcium sodium alginate and can be combined with collagen. The alginate forms a gel when in contact with the wound surface that can be lifted off with dressing removal or rinsed away with sterile saline  Hydrogel dressings Consist of an insoluble polymer and up to 96% water. Can absorb wound exudate or rehydrate a wound, depending on the wound moisture levels. Supplied as flat sheets, as an amorphous hydrogel or as beads  Films—permeable film and membrane dressings Permeable to water vapour and oxygen but not to water or microorganisms  Soft polymer dressings Composed of a soft silicone polymer held in a non-adherent layer. Moderately absorbent  Hydrocolloid dressings Occlusive dressing, usually composed of a hydrocolloid matrix on a vapour-permeable film or foam backing  Fibrous hydrocolloid dressing Fibrous hydrocolloids have been developed that resemble alginates and are not occlusive  Foam dressings Contain hydrophilic polyurethane foam; designed to absorb wound exudate and maintain moist wound surface  Capillary-action dressings Consist of an absorbent core of hydrophilic fibres held between two low-adherent contact layers  Odour-absorbent dressings Contain charcoal and used to absorb wound odour. Can be used in conjunction with a secondary dressing to improve absorbency Antimicrobial dressings  Iodine-impregnated dressings Release free iodine when exposed to wound exudate; iodine is thought to act as a wound antiseptic  Silver-impregnated dressings Used to treat infected wounds as silver ions are thought to have antimicrobial properties. Silver versions of most dressing types are available (e.g. silver foam, silver hydrocolloid)  Other antimicrobial dressings Composed of gauze or low-adherent dressing impregnated with ointment thought to have antimicrobial properties Specialist dressings  Protease-modulating matrix dressings Proposed to alter the activity of proteolytic enzymes in chronic wounds Dressing type . Description . Basic wound contact dressings  Low-adherence dressings and wound contact materials Usually cotton pads which are placed directly in contact with the wound. Can be either non-medicated (e.g. paraffin gauze dressing) or medicated (e.g. containing povidone–iodine or chlorhexidine)  Absorbent dressings Applied directly to the wound and may be used as secondary absorbent layers in the management of heavily exuding wounds Advanced wound dressings  Alginate dressings Highly absorbent; come in the form of calcium alginate or calcium sodium alginate and can be combined with collagen. The alginate forms a gel when in contact with the wound surface that can be lifted off with dressing removal or rinsed away with sterile saline  Hydrogel dressings Consist of an insoluble polymer and up to 96% water. Can absorb wound exudate or rehydrate a wound, depending on the wound moisture levels. Supplied as flat sheets, as an amorphous hydrogel or as beads  Films—permeable film and membrane dressings Permeable to water vapour and oxygen but not to water or microorganisms  Soft polymer dressings Composed of a soft silicone polymer held in a non-adherent layer. Moderately absorbent  Hydrocolloid dressings Occlusive dressing, usually composed of a hydrocolloid matrix on a vapour-permeable film or foam backing  Fibrous hydrocolloid dressing Fibrous hydrocolloids have been developed that resemble alginates and are not occlusive  Foam dressings Contain hydrophilic polyurethane foam; designed to absorb wound exudate and maintain moist wound surface  Capillary-action dressings Consist of an absorbent core of hydrophilic fibres held between two low-adherent contact layers  Odour-absorbent dressings Contain charcoal and used to absorb wound odour. Can be used in conjunction with a secondary dressing to improve absorbency Antimicrobial dressings  Iodine-impregnated dressings Release free iodine when exposed to wound exudate; iodine is thought to act as a wound antiseptic  Silver-impregnated dressings Used to treat infected wounds as silver ions are thought to have antimicrobial properties. Silver versions of most dressing types are available (e.g. silver foam, silver hydrocolloid)  Other antimicrobial dressings Composed of gauze or low-adherent dressing impregnated with ointment thought to have antimicrobial properties Specialist dressings  Protease-modulating matrix dressings Proposed to alter the activity of proteolytic enzymes in chronic wounds Open in new tab In 2008, a National Institute for Health and Clinical Excellence review of data from five randomized controlled trials (RCTs) concluded that current studies did not show convincing differences in SSI rates between different dressings used to treat surgical wounds8. Although the review methods were robust, the search date was September 2007; thus, more recent studies have not been assessed. This systematic review aimed to evaluate the effect of dressings on the prevention of SSI in surgical wounds healing by primary intention. Secondary outcomes of dressing costs, effects on scarring, and pain and acceptability were also examined. Methods Study selection criteria and literature searches A prespecified protocol defining the inclusion and exclusion criteria of studies was agreed by the authors. It included all published or unpublished RCTs, in any language, evaluating the effect of one dressing compared with another dressing or with no dressing at all (an exposed wound) on surgical wounds healing by primary intention, where the dressing was applied immediately after surgery. This included studies of children (aged over 2 years) and adults. Wounds of all contamination levels were eligible for inclusion. Procedures involving graft sites or where the patient had an infected wound before surgery were excluded. The wound dressings examined were categorized according to the BNF classification as either: basic wound contact dressings (BWCDs), which included absorbent dressings, low-adherence dressings, impregnated/non-impregnated gauze and adhesive tape; advanced wound dressings such as hydrogels, hydrocolloids and films; and other dressings, which included all dressings that did not fit these descriptions such as antimicrobial and specialist dressings (Table 2)7. The primary outcome was occurrence of postoperative SSI, as defined by Centers for Disease Control and Prevention criteria or the authors' definition of SSI. There was no differentiation between superficial and deep infection. Secondary outcomes of interest were: cost (any measure of cost of treatment, or other aspects of resource use such as equipment); pain, reported using a validated scale or as reported by the author; scarring, as reported by the author; acceptability (patient and clinician), as reported by the author; and ease of removal (patient and clinician), as reported by the author9. The search string for Cochrane Central Register of Controlled Trials (CENTRAL) was adapted for use in other databases, all being searched from inception to May 2011: Cochrane Wounds Group Specialised Register, CENTRAL, Ovid MEDLINE, Ovid Embase and EBSCO CINAHL (Appendix S1, supporting information). The Ovid MEDLINE search was combined with the Cochrane Highly Sensitive Search Strategy for identifying randomized trials in MEDLINE: sensitivity- and precision-maximizing version (2008 revision)10. The Embase and CINAHL searches were combined with the trial filters developed by the Scottish Intercollegiate Guidelines Network11. Bibliographies of all retrieved and relevant publications identified were searched for further studies, and attempts made to contact researchers where additional unpublished data were needed. No additional hand searches to those conducted by the Cochrane Wounds Group (which inform the CENTRAL database) were performed, nor were manufacturers contacted regarding studies for inclusion. Data extraction Two authors independently screened the titles and abstracts of all identified studies against the inclusion criteria. Articles with the potential to fulfil the criteria were obtained in full and checked for eligibility. Disagreements with regard to final inclusion were resolved by discussion and a third, independent, opinion. The following data were extracted: country of origin of trial; type of surgery; wound contamination (Table 1); eligibility criteria and baseline participant data; trial methodology reported; details of the dressing/treatment regimen received by each group; outcome data for primary and secondary outcomes; duration of follow-up; and number of withdrawals. Risk of bias assessment If any of the trials reported methodology demonstrating inadequate or unclear quality (as determined by the Cochrane Collaboration tool for assessing risk of bias) for the three key areas of trial design (generating the randomization sequence, allocation concealment and blinded outcome assessment), the trial was classified as having a high risk of bias12. Statistical analysis Data were stratified according to dressing type and wound contamination level. Estimates for dichotomous outcomes were reported as risk ratios (RR). Continuous data were reported as mean differences (MD), and overall effect sizes were calculated with 95 per cent confidence intervals (c.i.). χ2 test with P < 0·100 and an I2 value above 50 per cent were taken to indicate statistical heterogeneity. Where levels of clinical and statistical heterogeneity permitted, data were pooled using meta-analysis (conducted using Review Manager 5·1, available from http://ims.cochrane.org/revman/download)13. A random-effects model was applied if I2 values exceeded 50 per cent in the absence of clinical heterogeneity. For the primary outcome (SSI) it was assumed that where randomized participants were not included in an analysis, they did not have an SSI (that is, they were considered in the denominator but not the numerator). Given the relatively small number of SSI events anticipated, this seemed the most appropriate assumption. Where a trial did not specify participant group numbers before dropout, only complete case data were presented. Data for all secondary outcomes were presented as complete case analysis. For sensitivity analysis, data were presented by the contamination level of the surgery. A post hoc sensitivity analysis for SSI was also done, pooling data across surgical contamination types. Results A total of 16 RCTs involving 2594 participants met the inclusion criteria (Fig. 2); their study characteristics are shown in Table 314–29. Four of the 16 trials were three-armed trials, of which one was treated as a two-armed trial by combining the results from the two arms that randomized two different brands of film dressing14. Only five of the included trials had been published in the past 10 years14–18. The remaining 11 trials were between 12 and 31 years old19–29. Nine of the trials examined clean wounds, five examined clean and/or clean-contaminated wounds, and two examined clean and/or clean-contaminated and/or possibly contaminated wounds. Fig. 2 Open in new tabDownload slide PRISMA flow diagram for the trial. RCT, randomized clinical trial Table 3 Summary of all included trials Reference . Country . Duration of follow-up (days) . Wound contamination level . Interventions and no. randomized* . Primary outcome (SSI) . Secondary outcomes . BWCD versus exposed wounds (2 trials, 319 participants)  Phan et al.22 (1993) Belgium 20 Clean and clean-contaminated Group A: BWCD, 102 (86) A: 21 of 86 NS Group B: Exposed wound and Vaseline ointment, 105 (93) B: 29 of 93  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups Film dressing versus exposed wounds (1 trial, 107 participants)  Law and Ellis21 (1987)† UK NS Clean Group A: Film dressing, 54 A: 5 of 54 Cost: A, GBP 42·00; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups BWCD versus film dressing (8 trials, 1283 participants)‡  Cosker et al.14 (2005) UK NS Clean Group A: BWCD, 100 A: 5 of 100 NS Group B: 2 merged film dressing groups, 200 B: 9 of 200  De Win et al.23 (1998) Belgium 7–10 Clean Group A: BWCD, 6 A: 0 of 6 Cost: A, BEL 11·5; B, BEL 14·3 Group B: Film dressing, 8 B: 0 of 8  Gardezi et al.24 (1983) Pakistan NS Clean and clean-contaminated Group A: BWCD for 2 days, 50 A: 6 of 50 Pain: A, 1 of 50; B, 3 of 50 Group B: Film dressing for 7 days, 50 B: 3 of 50  Hewlett25 (1996) UK NS Clean and clean-contaminated Group A: BWCD, 39 NS Cost—dressing alone: A, GBP 1·60; B, GBP 1·46 Group B: Film dressing, 37 Cost—dressing and procedure packs: A, GBP 4·36; B, GBP 2·84  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 42·00 Group B: Film dressing, 54 B: 5 of 54 Scar: no difference between groups  Moshakis et al.19 (1984) UK 6–8 Clean Group A: BWCD, 59 NS Pain—patient assessment: A, 5·1(2·8); B, 1·6(1·5)† Group B: Film dressing, 61 Acceptability—patient assessment: A, 4·2(2·5); B, 1·3(1·2)† Acceptability—nurse assessment: A, 5·4; B, 1·2†  Rohde et al.26 (1981) Germany 10 Clean and clean-contaminated Group A: BWCD, 46 A: 24 of 46 Cost: A, DEM 10·40; B, DEM 3·60 Group B: Film dressing, 44 B: 14 of 44  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 1·59 Group B: Film dressing, 227 B: 9 of 227 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 166 of 227 BWCD versus hydrocolloid dressing (6 trials, 1084 participants)  Holm et al.28 (1998) Denmark 90 Clean and clean-contaminated, and possibly contaminated Group A: 2 days of BWCD, 37 A: 5 of 37 Scar width (mm): A, 2·3 (1–5); B, 1·8 (1–3)§ Group B: Hydrocolloid dressing, 36 B: 1 of 36  Michie and Hugill27 (1994) USA 183 Clean Group A: BWCD, 28 A: 0 of 28 Scar at 4 weeks—very or considerably supple: A, 23 of 26; B, 24 of 26. Group B: Hydrocolloid dressing, 28 B: 0 of 28 Scar at 4 weeks—raised: A, 14 of 26; B, 21 of 26 Pain over last 48 h at first and second postoperative visits on VAS 0–10: very low (< 1) in both groups  Persson et al.29 (1995) Sweden Until hospital Clean and clean-contaminated Group A: BWCD for 24 h followed by exposed, 30 A: 2 of 30 Pain—patients VAS 0–100 (mm): A, 40; B, 32  discharge Group B: Hydrocolloid dressing, 31 (7 postrandomized dropouts) B: 2 of 31  Shinohara et al.16 (2008) Japan 90 Clean and clean-contaminated, and possibly contaminated Group A: BWCD, 71 A: 4 of 71 Cost—per dressing: A, JPY 780; B, JPY 715 Group B: Hydrocolloid dressing, 63 B: 3 of 63 Scar width (mm): A, 2·3; B, 2·2†  Wikblad and Anderson20 (1995)† Sweden 28 Clean Group A: BWCD, 92 NS Cost—for days 1–5: A, USD 0·73; B, USD 3·60; C, USD 3·36 Group B: Hydrocolloid dressing, 77 Pain—no pain at removal on day 5: A, 76%; B, 61%; C, 14% Group C: Matrix hydrocolloid dressing, 81 Ease—difficult to remove (assessed by clinician): A, 5 of 84; B, 13 of 61; C, 45 of 60  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 3·93 Group B: Hydrocolloid dressing, 267 B: 6 of 267 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 202 of 267 Comparison of two different BWCDs (1 trial, 50 participants)  Lawrentschuk et al.15 (2002) Australia 5 Clean Group A: Absorbent BWCD, 25 A: 3 of 25 Group B: Paraffin tulle BWCD, 25 B: 0 of 25 BWCD versus fibrous hydrocolloid (hydrofibre) dressing (1 trial, 160 participants)  Vogt et al.17 (2007) Denmark 42 Clean Group A: BWCD, 80 A: 7 of 66 Cost—per patient: A, €10–11·8; B, €20·3–48·7 Group B: Hydrofibre dressing, 80 (24 participants, 14 from group A and 10 from group B postrandomization exclusions) B: 9 of 70 Pain—no. of patients with composite score of ‘good’ for discomfort on mobilization, dressing change and skin problems: A, 52 of 66; B, 59 of 70 BWCD versus polyurethane matrix hydrocolloid dressings (1 trial, 173 participants) see Wikblad and Anderson20) Comparisons of advanced dressings (2 trials, 652 participants; see Wikblad and Anderson20 and Wynne et al.18) Reference . Country . Duration of follow-up (days) . Wound contamination level . Interventions and no. randomized* . Primary outcome (SSI) . Secondary outcomes . BWCD versus exposed wounds (2 trials, 319 participants)  Phan et al.22 (1993) Belgium 20 Clean and clean-contaminated Group A: BWCD, 102 (86) A: 21 of 86 NS Group B: Exposed wound and Vaseline ointment, 105 (93) B: 29 of 93  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups Film dressing versus exposed wounds (1 trial, 107 participants)  Law and Ellis21 (1987)† UK NS Clean Group A: Film dressing, 54 A: 5 of 54 Cost: A, GBP 42·00; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups BWCD versus film dressing (8 trials, 1283 participants)‡  Cosker et al.14 (2005) UK NS Clean Group A: BWCD, 100 A: 5 of 100 NS Group B: 2 merged film dressing groups, 200 B: 9 of 200  De Win et al.23 (1998) Belgium 7–10 Clean Group A: BWCD, 6 A: 0 of 6 Cost: A, BEL 11·5; B, BEL 14·3 Group B: Film dressing, 8 B: 0 of 8  Gardezi et al.24 (1983) Pakistan NS Clean and clean-contaminated Group A: BWCD for 2 days, 50 A: 6 of 50 Pain: A, 1 of 50; B, 3 of 50 Group B: Film dressing for 7 days, 50 B: 3 of 50  Hewlett25 (1996) UK NS Clean and clean-contaminated Group A: BWCD, 39 NS Cost—dressing alone: A, GBP 1·60; B, GBP 1·46 Group B: Film dressing, 37 Cost—dressing and procedure packs: A, GBP 4·36; B, GBP 2·84  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 42·00 Group B: Film dressing, 54 B: 5 of 54 Scar: no difference between groups  Moshakis et al.19 (1984) UK 6–8 Clean Group A: BWCD, 59 NS Pain—patient assessment: A, 5·1(2·8); B, 1·6(1·5)† Group B: Film dressing, 61 Acceptability—patient assessment: A, 4·2(2·5); B, 1·3(1·2)† Acceptability—nurse assessment: A, 5·4; B, 1·2†  Rohde et al.26 (1981) Germany 10 Clean and clean-contaminated Group A: BWCD, 46 A: 24 of 46 Cost: A, DEM 10·40; B, DEM 3·60 Group B: Film dressing, 44 B: 14 of 44  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 1·59 Group B: Film dressing, 227 B: 9 of 227 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 166 of 227 BWCD versus hydrocolloid dressing (6 trials, 1084 participants)  Holm et al.28 (1998) Denmark 90 Clean and clean-contaminated, and possibly contaminated Group A: 2 days of BWCD, 37 A: 5 of 37 Scar width (mm): A, 2·3 (1–5); B, 1·8 (1–3)§ Group B: Hydrocolloid dressing, 36 B: 1 of 36  Michie and Hugill27 (1994) USA 183 Clean Group A: BWCD, 28 A: 0 of 28 Scar at 4 weeks—very or considerably supple: A, 23 of 26; B, 24 of 26. Group B: Hydrocolloid dressing, 28 B: 0 of 28 Scar at 4 weeks—raised: A, 14 of 26; B, 21 of 26 Pain over last 48 h at first and second postoperative visits on VAS 0–10: very low (< 1) in both groups  Persson et al.29 (1995) Sweden Until hospital Clean and clean-contaminated Group A: BWCD for 24 h followed by exposed, 30 A: 2 of 30 Pain—patients VAS 0–100 (mm): A, 40; B, 32  discharge Group B: Hydrocolloid dressing, 31 (7 postrandomized dropouts) B: 2 of 31  Shinohara et al.16 (2008) Japan 90 Clean and clean-contaminated, and possibly contaminated Group A: BWCD, 71 A: 4 of 71 Cost—per dressing: A, JPY 780; B, JPY 715 Group B: Hydrocolloid dressing, 63 B: 3 of 63 Scar width (mm): A, 2·3; B, 2·2†  Wikblad and Anderson20 (1995)† Sweden 28 Clean Group A: BWCD, 92 NS Cost—for days 1–5: A, USD 0·73; B, USD 3·60; C, USD 3·36 Group B: Hydrocolloid dressing, 77 Pain—no pain at removal on day 5: A, 76%; B, 61%; C, 14% Group C: Matrix hydrocolloid dressing, 81 Ease—difficult to remove (assessed by clinician): A, 5 of 84; B, 13 of 61; C, 45 of 60  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 3·93 Group B: Hydrocolloid dressing, 267 B: 6 of 267 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 202 of 267 Comparison of two different BWCDs (1 trial, 50 participants)  Lawrentschuk et al.15 (2002) Australia 5 Clean Group A: Absorbent BWCD, 25 A: 3 of 25 Group B: Paraffin tulle BWCD, 25 B: 0 of 25 BWCD versus fibrous hydrocolloid (hydrofibre) dressing (1 trial, 160 participants)  Vogt et al.17 (2007) Denmark 42 Clean Group A: BWCD, 80 A: 7 of 66 Cost—per patient: A, €10–11·8; B, €20·3–48·7 Group B: Hydrofibre dressing, 80 (24 participants, 14 from group A and 10 from group B postrandomization exclusions) B: 9 of 70 Pain—no. of patients with composite score of ‘good’ for discomfort on mobilization, dressing change and skin problems: A, 52 of 66; B, 59 of 70 BWCD versus polyurethane matrix hydrocolloid dressings (1 trial, 173 participants) see Wikblad and Anderson20) Comparisons of advanced dressings (2 trials, 652 participants; see Wikblad and Anderson20 and Wynne et al.18) * Values in parentheses denote patient attrition. † Three-armed trial; ‡ includes the three-armed trials of Law and Ellis21 and Wynne etal.18; †values are mean(s.d.); § values are mean (range). SSI, surgical-site infection; BWCD, basic wound contact dressing; NS, not stated; GBP, Great British Pound; BEL, Belgium Franc (now replaced by the Euro); DEM, Deutsche Mark (now replaced by the Euro); AUD, Australian Dollar; VAS, visual analogue scale; JPY, Japanese Yen; USD, United States Dollar). Open in new tab Table 3 Summary of all included trials Reference . Country . Duration of follow-up (days) . Wound contamination level . Interventions and no. randomized* . Primary outcome (SSI) . Secondary outcomes . BWCD versus exposed wounds (2 trials, 319 participants)  Phan et al.22 (1993) Belgium 20 Clean and clean-contaminated Group A: BWCD, 102 (86) A: 21 of 86 NS Group B: Exposed wound and Vaseline ointment, 105 (93) B: 29 of 93  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups Film dressing versus exposed wounds (1 trial, 107 participants)  Law and Ellis21 (1987)† UK NS Clean Group A: Film dressing, 54 A: 5 of 54 Cost: A, GBP 42·00; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups BWCD versus film dressing (8 trials, 1283 participants)‡  Cosker et al.14 (2005) UK NS Clean Group A: BWCD, 100 A: 5 of 100 NS Group B: 2 merged film dressing groups, 200 B: 9 of 200  De Win et al.23 (1998) Belgium 7–10 Clean Group A: BWCD, 6 A: 0 of 6 Cost: A, BEL 11·5; B, BEL 14·3 Group B: Film dressing, 8 B: 0 of 8  Gardezi et al.24 (1983) Pakistan NS Clean and clean-contaminated Group A: BWCD for 2 days, 50 A: 6 of 50 Pain: A, 1 of 50; B, 3 of 50 Group B: Film dressing for 7 days, 50 B: 3 of 50  Hewlett25 (1996) UK NS Clean and clean-contaminated Group A: BWCD, 39 NS Cost—dressing alone: A, GBP 1·60; B, GBP 1·46 Group B: Film dressing, 37 Cost—dressing and procedure packs: A, GBP 4·36; B, GBP 2·84  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 42·00 Group B: Film dressing, 54 B: 5 of 54 Scar: no difference between groups  Moshakis et al.19 (1984) UK 6–8 Clean Group A: BWCD, 59 NS Pain—patient assessment: A, 5·1(2·8); B, 1·6(1·5)† Group B: Film dressing, 61 Acceptability—patient assessment: A, 4·2(2·5); B, 1·3(1·2)† Acceptability—nurse assessment: A, 5·4; B, 1·2†  Rohde et al.26 (1981) Germany 10 Clean and clean-contaminated Group A: BWCD, 46 A: 24 of 46 Cost: A, DEM 10·40; B, DEM 3·60 Group B: Film dressing, 44 B: 14 of 44  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 1·59 Group B: Film dressing, 227 B: 9 of 227 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 166 of 227 BWCD versus hydrocolloid dressing (6 trials, 1084 participants)  Holm et al.28 (1998) Denmark 90 Clean and clean-contaminated, and possibly contaminated Group A: 2 days of BWCD, 37 A: 5 of 37 Scar width (mm): A, 2·3 (1–5); B, 1·8 (1–3)§ Group B: Hydrocolloid dressing, 36 B: 1 of 36  Michie and Hugill27 (1994) USA 183 Clean Group A: BWCD, 28 A: 0 of 28 Scar at 4 weeks—very or considerably supple: A, 23 of 26; B, 24 of 26. Group B: Hydrocolloid dressing, 28 B: 0 of 28 Scar at 4 weeks—raised: A, 14 of 26; B, 21 of 26 Pain over last 48 h at first and second postoperative visits on VAS 0–10: very low (< 1) in both groups  Persson et al.29 (1995) Sweden Until hospital Clean and clean-contaminated Group A: BWCD for 24 h followed by exposed, 30 A: 2 of 30 Pain—patients VAS 0–100 (mm): A, 40; B, 32  discharge Group B: Hydrocolloid dressing, 31 (7 postrandomized dropouts) B: 2 of 31  Shinohara et al.16 (2008) Japan 90 Clean and clean-contaminated, and possibly contaminated Group A: BWCD, 71 A: 4 of 71 Cost—per dressing: A, JPY 780; B, JPY 715 Group B: Hydrocolloid dressing, 63 B: 3 of 63 Scar width (mm): A, 2·3; B, 2·2†  Wikblad and Anderson20 (1995)† Sweden 28 Clean Group A: BWCD, 92 NS Cost—for days 1–5: A, USD 0·73; B, USD 3·60; C, USD 3·36 Group B: Hydrocolloid dressing, 77 Pain—no pain at removal on day 5: A, 76%; B, 61%; C, 14% Group C: Matrix hydrocolloid dressing, 81 Ease—difficult to remove (assessed by clinician): A, 5 of 84; B, 13 of 61; C, 45 of 60  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 3·93 Group B: Hydrocolloid dressing, 267 B: 6 of 267 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 202 of 267 Comparison of two different BWCDs (1 trial, 50 participants)  Lawrentschuk et al.15 (2002) Australia 5 Clean Group A: Absorbent BWCD, 25 A: 3 of 25 Group B: Paraffin tulle BWCD, 25 B: 0 of 25 BWCD versus fibrous hydrocolloid (hydrofibre) dressing (1 trial, 160 participants)  Vogt et al.17 (2007) Denmark 42 Clean Group A: BWCD, 80 A: 7 of 66 Cost—per patient: A, €10–11·8; B, €20·3–48·7 Group B: Hydrofibre dressing, 80 (24 participants, 14 from group A and 10 from group B postrandomization exclusions) B: 9 of 70 Pain—no. of patients with composite score of ‘good’ for discomfort on mobilization, dressing change and skin problems: A, 52 of 66; B, 59 of 70 BWCD versus polyurethane matrix hydrocolloid dressings (1 trial, 173 participants) see Wikblad and Anderson20) Comparisons of advanced dressings (2 trials, 652 participants; see Wikblad and Anderson20 and Wynne et al.18) Reference . Country . Duration of follow-up (days) . Wound contamination level . Interventions and no. randomized* . Primary outcome (SSI) . Secondary outcomes . BWCD versus exposed wounds (2 trials, 319 participants)  Phan et al.22 (1993) Belgium 20 Clean and clean-contaminated Group A: BWCD, 102 (86) A: 21 of 86 NS Group B: Exposed wound and Vaseline ointment, 105 (93) B: 29 of 93  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups Film dressing versus exposed wounds (1 trial, 107 participants)  Law and Ellis21 (1987)† UK NS Clean Group A: Film dressing, 54 A: 5 of 54 Cost: A, GBP 42·00; B, GBP 0·80 Group B: Exposed wound, 53 B: 1 of 53 Scar: no difference between groups BWCD versus film dressing (8 trials, 1283 participants)‡  Cosker et al.14 (2005) UK NS Clean Group A: BWCD, 100 A: 5 of 100 NS Group B: 2 merged film dressing groups, 200 B: 9 of 200  De Win et al.23 (1998) Belgium 7–10 Clean Group A: BWCD, 6 A: 0 of 6 Cost: A, BEL 11·5; B, BEL 14·3 Group B: Film dressing, 8 B: 0 of 8  Gardezi et al.24 (1983) Pakistan NS Clean and clean-contaminated Group A: BWCD for 2 days, 50 A: 6 of 50 Pain: A, 1 of 50; B, 3 of 50 Group B: Film dressing for 7 days, 50 B: 3 of 50  Hewlett25 (1996) UK NS Clean and clean-contaminated Group A: BWCD, 39 NS Cost—dressing alone: A, GBP 1·60; B, GBP 1·46 Group B: Film dressing, 37 Cost—dressing and procedure packs: A, GBP 4·36; B, GBP 2·84  Law and Ellis21 (1987)† UK NS Clean Group A: BWCD, 59 A: 3 of 59 Cost: A, GBP 6·60; B, GBP 42·00 Group B: Film dressing, 54 B: 5 of 54 Scar: no difference between groups  Moshakis et al.19 (1984) UK 6–8 Clean Group A: BWCD, 59 NS Pain—patient assessment: A, 5·1(2·8); B, 1·6(1·5)† Group B: Film dressing, 61 Acceptability—patient assessment: A, 4·2(2·5); B, 1·3(1·2)† Acceptability—nurse assessment: A, 5·4; B, 1·2†  Rohde et al.26 (1981) Germany 10 Clean and clean-contaminated Group A: BWCD, 46 A: 24 of 46 Cost: A, DEM 10·40; B, DEM 3·60 Group B: Film dressing, 44 B: 14 of 44  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 1·59 Group B: Film dressing, 227 B: 9 of 227 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 166 of 227 BWCD versus hydrocolloid dressing (6 trials, 1084 participants)  Holm et al.28 (1998) Denmark 90 Clean and clean-contaminated, and possibly contaminated Group A: 2 days of BWCD, 37 A: 5 of 37 Scar width (mm): A, 2·3 (1–5); B, 1·8 (1–3)§ Group B: Hydrocolloid dressing, 36 B: 1 of 36  Michie and Hugill27 (1994) USA 183 Clean Group A: BWCD, 28 A: 0 of 28 Scar at 4 weeks—very or considerably supple: A, 23 of 26; B, 24 of 26. Group B: Hydrocolloid dressing, 28 B: 0 of 28 Scar at 4 weeks—raised: A, 14 of 26; B, 21 of 26 Pain over last 48 h at first and second postoperative visits on VAS 0–10: very low (< 1) in both groups  Persson et al.29 (1995) Sweden Until hospital Clean and clean-contaminated Group A: BWCD for 24 h followed by exposed, 30 A: 2 of 30 Pain—patients VAS 0–100 (mm): A, 40; B, 32  discharge Group B: Hydrocolloid dressing, 31 (7 postrandomized dropouts) B: 2 of 31  Shinohara et al.16 (2008) Japan 90 Clean and clean-contaminated, and possibly contaminated Group A: BWCD, 71 A: 4 of 71 Cost—per dressing: A, JPY 780; B, JPY 715 Group B: Hydrocolloid dressing, 63 B: 3 of 63 Scar width (mm): A, 2·3; B, 2·2†  Wikblad and Anderson20 (1995)† Sweden 28 Clean Group A: BWCD, 92 NS Cost—for days 1–5: A, USD 0·73; B, USD 3·60; C, USD 3·36 Group B: Hydrocolloid dressing, 77 Pain—no pain at removal on day 5: A, 76%; B, 61%; C, 14% Group C: Matrix hydrocolloid dressing, 81 Ease—difficult to remove (assessed by clinician): A, 5 of 84; B, 13 of 61; C, 45 of 60  Wynne et al.18 (2004)† Australia 28 Clean Group A: BWCD, 243 A: 6 of 243 Cost—per person: A, AUD 0·52; B, AUD 3·93 Group B: Hydrocolloid dressing, 267 B: 6 of 267 Discomfort—on dressing removal (as reported by patient): A, 142 of 243; B, 202 of 267 Comparison of two different BWCDs (1 trial, 50 participants)  Lawrentschuk et al.15 (2002) Australia 5 Clean Group A: Absorbent BWCD, 25 A: 3 of 25 Group B: Paraffin tulle BWCD, 25 B: 0 of 25 BWCD versus fibrous hydrocolloid (hydrofibre) dressing (1 trial, 160 participants)  Vogt et al.17 (2007) Denmark 42 Clean Group A: BWCD, 80 A: 7 of 66 Cost—per patient: A, €10–11·8; B, €20·3–48·7 Group B: Hydrofibre dressing, 80 (24 participants, 14 from group A and 10 from group B postrandomization exclusions) B: 9 of 70 Pain—no. of patients with composite score of ‘good’ for discomfort on mobilization, dressing change and skin problems: A, 52 of 66; B, 59 of 70 BWCD versus polyurethane matrix hydrocolloid dressings (1 trial, 173 participants) see Wikblad and Anderson20) Comparisons of advanced dressings (2 trials, 652 participants; see Wikblad and Anderson20 and Wynne et al.18) * Values in parentheses denote patient attrition. † Three-armed trial; ‡ includes the three-armed trials of Law and Ellis21 and Wynne etal.18; †values are mean(s.d.); § values are mean (range). SSI, surgical-site infection; BWCD, basic wound contact dressing; NS, not stated; GBP, Great British Pound; BEL, Belgium Franc (now replaced by the Euro); DEM, Deutsche Mark (now replaced by the Euro); AUD, Australian Dollar; VAS, visual analogue scale; JPY, Japanese Yen; USD, United States Dollar). Open in new tab Risk of bias assessment Three trials were deemed to be at high risk of bias18–20. The quality of the remaining trials was unclear as their reports lacked adequate detail to be confident that they were at low risk of bias14–17,21–29. Effects of interventions: prevention of surgical-site infection (primary outcome) Table 3 shows the SSI rates and secondary outcome results of each trial grouped according to the different dressings compared; in total, eight comparisons between dressings (or wound exposure) were made. There were no significant differences in SSI rates between dressings or exposed wounds in any of the included trials. Data were available for meta-analysis for two comparisons. Basic wound contact dressings versus film dressings Data from four of the eight trials comparing BWCDs with film dressings involved clean surgical wounds and were pooled14,18,21,23. Although two of these studies were three-armed trials, this was the only meta-analysis conducted with their data, so the complete groups relevant to this pooling were used18,21. Data from the remaining fifth clean study could not be pooled because the article did not report SSI data19. Pooled data showed there was no significant difference in the number of SSIs between basic wound contact-dressed groups and film-dressed groups (RR 1·34, 95 per cent c.i. 0·70 to 2·55) (Fig. 3)14,18,21. Fig. 3 Open in new tabDownload slide Meta-analysis of surgical-site infection (SSI) rates for basic wound contact dressings compared with film dressings in clean surgery using a Mantel–Haenszel model. Odds ratios are shown with 95 per cent confidence intervals. De Win et al.23 was not included as there were no SSIs in either arm The remaining trials in the BWCD versus film dressing comparison either failed to report their surgical type and SSI data, or reported unclear surgical wound contamination types24–26. As it is not clear what impact the level of surgical contamination might have on the potential action of dressings in SSI prevention, a sensitivity analysis was performed with pooled data from all six trials that reported SSI data in this comparison, regardless of contamination level (Fig. 4)14,18,21,24,26. This showed there was no significant difference in the number of SSIs between BWCD and film-dressed groups (RR 0·84, 0·58 to 1·24). Fig. 4 Open in new tabDownload slide Meta-analysis of surgical-site infection (SSI) rates for basic wound contact dressings compared with film dressings in all trials (mixed contamination levels) using a Mantel–Haenszel model. Odds ratios are shown with 95 per cent confidence intervals. De Win et al.23 was not included as there were no SSIs in either arm Basic wound contact dressings versus hydrocolloid dressings Of the six trials investigating the effect of a BWCD compared with a hydrocolloid dressing16,18,20,27–29, only four reported SSI data across a mixture of wound contamination groups, so data were not pooled initially. In sensitivity analysis, pooling data from all trials reporting SSI rates, no significant difference in the number of SSIs between BWCD and hydrocolloid-dressed groups was seen (RR 0·70, 0·34 to 1·44) (Fig. 5)16,18,28,29. Fig. 5 Open in new tabDownload slide Meta-analysis of surgical-site infection (SSI) rates for basic wound contact dressings compared with hydrocolloid dressings in all trials (mixed contamination levels) using a Mantel–Haenszel model. Odds ratios are shown with 95 per cent confidence intervals. Michie and Hugill27 was not included as there were no SSIs in either arm Effects of interventions: secondary outcomes Costs Dressing cost was reported in a number of trials. Although exposed wounds were cheaper than dressed wounds, no single type of wound dressing (BWCD, hydrocolloid or film) was consistently cheaper than the others, with costs appearing to vary based on the individual dressing products used (Table 3)16–18,20,21,23,25,26. Pain Few studies provided meaningful data on pain. When comparing a BWCD with a film dressing, Moshakis and colleagues19 measured pain using a patient-assessed linear scale (1–10), where 1 corresponded to ‘no discomfort’ and 10 to ‘extremely uncomfortable or painful’; mean(s.d.) pain levels in the basic wound contact group were 5·1(2·8) compared with 1·6(1·5) in the film-dressed group, a statistically significant finding in favour of film dressings (MD − 3·50, 95 per cent c.i. − 4·29 to − 2·71). However, all analyses in this trial must be interpreted with caution, as it was deemed to be at high risk of bias. The study of Wynne and co-workers18 reported BWCDs to be less painful on removal than a hydrocolloid dressing, but the difference was not statistically significant (0·80, 0·63 to 1·01). Wikblad and Anderson20 compared pain on dressing removal for BWCDs and a hydrocolloid matrix dressing, and reported a statistically significant difference in the proportion of participants with no pain on removal in favour of the BWCD (0·17, 0·09 to 0·34); however, the large number of missing data should be noted. Scarring, acceptability and ease of removal Results from a variety of ad hoc scarring, acceptability and ease of removal measures were reported from the trials. No clear advantages for any of the dressing categories (or wound exposure) over the others were seen with respect to these outcomes (Table 3). Discussion This systematic review found no evidence that dressing surgical wounds reduces rates of SSI in comparison with leaving the wounds uncovered. Furthermore, no evidence was demonstrated to support the use of one type of dressing over another in SSI prevention. Many trials that investigated non-‘clean’ surgery evaluated a range of contamination levels, so it was not possible to draw conclusions for each scenario. A number of trials also had low numbers of participants and low event rates. Their results require cautious interpretation as this low statistical power leaves the equivalent findings at risk of a type II error, where a real difference in a dressing's effectiveness may exist but has not been demonstrated. In terms of secondary outcomes, there is only weak evidence to suggest that one dressing type has advantages over another. Moshakis et al.19 suggested that film dressings might be less painful for patients than BWCDs. This study, however, was deemed to be at high risk of bias owing to inadequate allocation concealment and the absence of evidence that statistical procedures had been employed to deal with the inclusion of some participants as their own controls (bilateral excisions). Wikblad and Anderson20 reported that BWCDs were significantly less painful on removal than hydrocolloid dressings, but as a large number of data were missing from this analysis it, too, was deemed to be at high risk of bias. A number of trials suggested that advanced dressings were more expensive than BWCDs; however, these limited cost evaluations did not capture all relevant data on resource use, or consider the costs versus the benefits of treatments18,20,21,23. Consequently, the cost-effectiveness data included in these studies are not suitable to guide a surgeon's dressing choice. As the justification to dress surgical wounds is not supported by reductions in SSI rates, decisions to use surgical wound dressings might be better based on the other properties and qualities that dressings can offer. Yet, this review highlights that few trials have sought to examine these properties or produce high-quality cost and benefit evaluations. Thus, based on the current evidence, wound dressing choice should be made simply with regard to unit dressing costs and the ability of different dressings to manage specific symptoms such as absorption of exudate. While this uncertainty regarding best dressings for surgical wounds remains, any investment in future research must maximize its value to clinicians. Given the large number of both dressing options and surgical procedures, future trials should focus on evaluating dressings or approaches that surgical teams use most often. It would be important to ask surgeons, nurses and patients what they feel are the most pressing questions, such as which type of dressing, or for what duration, a dressing should remain in place, as well as which outcomes are most important. Understanding these questions would allow research resources to be focused on addressing the most pressing issues. Supporting information Additional supporting information may be found in the online version of this article: Appendix S1 Search strategy employed for the systematic review of wound dressings in the prevention of surgical-site infections in surgical wounds healing by primary intention (Word document) Please note: John Wiley & Sons Ltd is not responsible for the functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. Acknowledgements This paper was generated from work that contributed towards the Cochrane Review published as Cochrane Database Syst Rev 2011; (7)CD003091. The authors would like to acknowledge the contribution of all peer referees who commented on that Cochrane Review. They also thank members of the editorial base of the Cochrane Wounds Group for their support. Disclosure: The authors declare no conflict of interest. References 1 Weiser TG , Regenbogen SE, Thompson KD, Haynes AB, Lipsitz SR, Berry WR et al. An estimation of the global volume of surgery: a modelling strategy based on available data . Lancet 2008 ; 372 : 139 – 144 . Google Scholar Crossref Search ADS PubMed WorldCat 2 Health Protection Agency . Surveillance of Surgical Site Infection in English Hospitals 1997–2002. A National Surveillance and Quality Improvement Programme . Health Protection Agency : London , 2002 . 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Google Scholar PubMed OpenURL Placeholder Text WorldCat Author notes Presented to the Tripartite Colorectal Meeting, Cairns, Queensland, Australia, July 2011, the International Surgical Congress of the Association of Surgeons of Great Britain and Ireland, Bournemouth, UK, May 2011, and the Annual Meeting of the Association of Coloproctology of Great Britain and Ireland, Birmingham, UK, June 2011; published in abstract form as Br J Surg 2011; 98: 19S, Colorectal Dis 2011; 13: 47 and Colorectal Dis 2011; 13: 83 Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
TI - Systematic review and meta-analysis of wound dressings in the prevention of surgical-site infections in surgical wounds healing by primary intention
JF - British Journal of Surgery
DO - 10.1002/bjs.8812
DA - 2012-08-02
UR - https://www.deepdyve.com/lp/oxford-university-press/systematic-review-and-meta-analysis-of-wound-dressings-in-the-fDMClx6FjR
SP - 1185
EP - 1194
VL - 99
IS - 9
DP - DeepDyve
ER -