The impact of hypnotics usage on daytime function and associated factor for the usage in shiftwork nurses

Abstract

Introduction It has been known that a certain number of shiftwork nurses have shift work disorder (SWD) and regularly take hypnotics. @However, impact of hypnotics usage on health-related quality of life (QOL) and daytime function in shiftwork nurses remain unclear. Especially, condition of usage of high dose or multiple kinds of hypnotics, which is likely to cause dependency of hypnotics, has not been investigated in this population. To clarify this issue, we investigated QOL and work performance status of hypnotic user and explored the factors associated with multiple hypnotics usage in shiftwork nurses. Materials and methods We conducted a questionnaire-based, cross-sectional survey on nurses working in university hospitals. The questionnaires included items relevant to age, gender, family member structure, work environment, history of work-related accidents/errors, social functioning 8 (SF8), chronotype, sleep problems, status of hypnotics usage, the Center for Epidemiological Studies Depression Scale (CESD) and presence/absence of SWD. Responses were obtained from 1202 nurses. Among them, 997 female shift work nurses including 696 two-shift workers and 281 three-shift workers were subjected for the analyses. Results The prevalence of hypnotics usage in the sampled shiftwork nurses was 10.0% (6.9% were single hypnotics users and 3.1% were multiple hypnotics users). The diazepam equivalent dose of benzoziazepine or benzoziazepine agonist hypnotics were significantly higher in the multiple hypnotics users than in the single hypnotics users. The number of nurses having insomnia were not different between the single hypnotics users and the multiple hypnotics users. The sampled sfiftwork nurses with usage of multiple hypnotics showed lower QOL, more severe depressive symptoms and greater frequencies of work-related accidents / errors than those with usage of single hypnotics. A multiple logistic regression analyses revealed that age (over 27 years old), insomnia, existence of SWD, longer working hours and having an eveningness-oriented chronotype were significantly associated with usage of hypnotics. However, as for multiple hypnotics, only existence of SWD was significantly associated with the usage. Conclusion The present study indicated that usage of multiple hypnotics does not necessarily bring about improvement of insomnia or QOL in shiftwork nurses. It was also suggested that prevention of SWD is needed to avoid multiple hypnotics usage in this population. Acknowledgements We thank members of the Department of Somnology of Tokyo Medical University for technical support.