International Archives of Occupational and Environmental Health (2018) 91:695–704
Eﬀects of night-time on-call work on heart rate variability before bed
and sleep quality in visiting nurses
· Noriko Ishii
· Hideya Kodama
Received: 15 June 2017 / Accepted: 22 May 2018 / Published online: 28 May 2018
© Springer-Verlag GmbH Germany, part of Springer Nature 2018
Purpose In Japan, many visiting nurses work carrying cell phones to respond to calls from users even at night (on-call
work). The purpose of this study was to investigate whether on-call work aﬀected heart rate variability (HRV) before bed
and decreased sleep quality in visiting nurses even if their sleep was not interrupted due to actual calls.
Methods Thirty-one visiting nurses (mean age, 49.8 years; standard deviation, 6.3 years) were asked to record their 2.5-min
resting HRV before bed, and to undergo one-channel sleep electroencephalography (EEG) and subjective sleep evaluations
upon waking (Oguri, Shirakawa, and Azumi Sleep Inventory) at home for 4–5 consecutive days, including both on-call and
non-on-call days. Paired data sets of outcome measures, including HRV parameters, sleep macrostructure variables, and
subjective sleep quality scores between on-call and non-on-call days were compared; the most recent measurements for each
category were used for each subject.
Results There were no diﬀerences in HRV measures and objective sleep EEG variables. A signiﬁcant increase in “sleepi-
ness on rising” and a decrease in “feeling refreshed” were observed on on-call days (P = 0.019 and 0.021, respectively),
and younger subjects (≤ 51 years old) demonstrated a signiﬁcant reduction in “sleepiness on rising” (signiﬁcant interaction
eﬀect, P = 0.029).
Conclusions Adverse eﬀects of on-call work on sleep quality in most visiting nurses are thought to be subjective, and rela-
tively young nurses tend to notice a decrease in sleep quality. On-call work itself does not appear to be a substantial stressor
that could aﬀect HRV and sleep structure.
Keywords Community-based care · Visiting nurses · Sleep quality · Heart rate variability · On-call work · Job stress
In Japan, to prepare for the rapidly growing elderly popula-
tion, a transformation from traditional hospital-based medi-
cal care to community-based integrated care that focuses
on home care is progressing (Matsuda et al. 2013). Under
such social circumstances, there is an expansion in the role
of visiting nurses who directly visit patients in their com-
munity or at home to provide care (Tachibana et al. 2001;
Kanbara et al. 2017). Visiting nurses are staﬀed at regional
visiting nurse stations and provide eﬀective support services
to patients (Akiyama et al. 2011; Kashiwagi et al. 2015).
Visiting nurse stations are required to respond to various tel-
ephone consultations (“calls”) from users at any hour during
the day. For this reason, many of these visiting nurses work
carrying cell phones to respond to emergency calls from
patients or others even at night or on weekends and holidays
(hereinafter “on-call work”) (Kikuchi and Ishii 2016). For
many visiting nurses, such on-call work, especially during
the night, may become a latent work-related stress factor that
cannot be ignored (Buyukhatipoglu et al. 2010; Heponiemi
et al. 2016; Kikuchi and Ishii 2016).
The interruption of sleep due to calls is associated with a
variety of physical and mental health risks in medical profes-
sionals who perform on-call work during the night (Saxena
and George 2005; Buyukhatipoglu et al. 2010; Wada et al.
2010; Tobaldini et al. 2013; Ernst et al. 2014; Heponiemi
et al. 2016). Thus, the adverse eﬀects on sleep quality are
a troublesome issue for visiting nurses. According to our
* Hideya Kodama
Akita University Graduate School of Medicine and Faculty
of Medicine, School of Health Sciences, Akita, Japan
Hokkaido University of Science, Faculty of Health Sciences,