Employees with shift work disorder experience excessive sleepiness also onnon-work days: a cross-sectional survey linked to working hours register in Finnishhospitals

摘要

A considerable proportion of shift workers have work schedule-related insomniaand/or excessive sleepiness, a phenomenon described as shift work disorder (SWD). There isyet a lack of evidence on whether or not employees recover from symptoms of SWD betweenwork shifts. We studied whether SWD and its subtypes are associated with insomnia andexcessive sleepiness during weekly non-work days and with 24-h sleep time. Hospitalemployees answered a survey on SWD, insomnia and excessive sleepiness on weekly non-workdays, and 24-h sleep. To identify shift workers with night shifts (n=2,900, 18% with SWD)and SWD, we linked survey responses to employers’ register on working hours. SWD includedthree subtypes: insomnia only (SWD-I, 4%, n=102), excessive sleepiness only (SWD-Es, 8%,n=244), and both insomnia and excessive sleepiness (SWD-IEs, 6%, n=183). Based onregression analyses, SWD was associated with excessive sleepiness on non-work days (OR:1.42, 95% CI: 1.07–1.88) and with insomnia on non-work days (0.53, 0.31–0.91). SWD-I wasassociated with excessive sleepiness on non-work days (2.25, 1.31–3.87) and with shortersleep (7–7.5 h: 1.96, 1.06–3.63; ≤6.5h: 2.39, 1.24–4.59; reference: ≥8 h). The resultssuggest that especially employees with SWD-I may need longer time to overcome excessivesleepiness than allowed by their roster.