The association between proportion of night shifts and musculoskeletal pain and headaches in nurses: a cross-sectional study

Abstract

ABSTRACTObjectivesTo investigate whether a higher proportion of night shifts is associated with a higher occurrence of musculoskeletal pain and headaches. Furthermore, to investigate whether sleep duration can mediate this potential association.MethodThe study included 684 nurses in rotating shift work (day, evening, night) who responded to a daily questionnaire about working hours, sleep, and pain for 28 consecutive days. The data were treated as cross-sectional data.ResultsA negative binomial regression analysis adjusted for age and BMI revealed that working a higher proportion of night shifts is not associated with a higher occurrence of musculoskeletal pain and headaches. On the contrary, those working ≥ 50 % night shifts had a significantly lower occurrence of pain in the lower extremities than those who worked <25 % night shifts (IRR 0.69 95 % CI 0.51, 0.94). There was no indication of a mediation effect with total sleep time (TST).ConclusionThe results of this study indicate that working a higher monthly proportion of night shifts is not associated with a higher occurrence of musculoskeletal pain and headaches.What is already known on this topic?A few studies have investigated the association between proportion of night shifts and musculoskeletal pain and headaches, but the findings are conflicting, and the studies are largely based on retrospective questionnaires.What this study addsThis study gives further knowledge about the association between proportion of night shifts and musculoskeletal pain and headaches.How this study might affect research, practice or policyThe results have implications for the design of future studies on the effect of shift work on musculoskeletal pain and headache. The negative effect of night shifts are not necessarily dose-dependent, and real-life studies must seek to account for the “healthy worker effect”.