title: Subjective and objective evaluation of sleep and performance in daytime versus nighttime sleep in extended-hours shift-workers at an underground mine.
abstract: Extended hours of shift work has the potential for adverse consequences for workers, particularly during the nightshift, such as poorer sleep quality during the day, increased worker fatigue, and fatigue-related accidents and decreased work performance. This study examined subjective and objective measurements of sleep and performance in a group of underground miners before and after the change from a backward-rotating 8-hour to a forward-rotating 10-hour shift schedule. The purpose of this study was to evaluate the short- and long-term impact of a shift schedule change on sleep and performance. The results demonstrated improved subjective and objective measures of sleep and performance on the new 10-hour nightshift schedule. The 10-hour nightshift workers subjectively reported more refreshing sleep, fewer performance impairments and driving difficulties than 8-hour nightshift workers. The results of the objective measures of sleep and performance on the 10-hour nightshifts were overall similar or possibly better than those measured on the 10-hour dayshifts. These are some of the first data to suggest that a nightshift that does not encompass the entire night period could have significant benefits to shift-workers. We suggest that these benefits are mostly the result of the timing of the new nightshift start and end times rather than other shift-schedule factors.
authors.affiliation: Sleep Research Laboratory and the Department of Psychiatry, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
authors.forename: Jamil L
authors.initials: JL
authors.lastname: Hossain
authors.forename: Lawrence W
authors.initials: LW
authors.lastname: Reinish
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Heslegrave
authors.forename: Gordon W
authors.initials: GW
authors.lastname: Hall
authors.forename: Leonid
authors.initials: L
authors.lastname: Kayumov
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Chung
authors.forename: Pintu
authors.initials: P
authors.lastname: Bhuiya
authors.forename: Dragona
authors.initials: D
authors.lastname: Jovanovic
authors.forename: Nada
authors.initials: N
authors.lastname: Huterer
authors.forename: Jana
authors.initials: J
authors.lastname: Volkov
authors.forename: Colin M
authors.initials: CM
authors.lastname: Shapiro
mesh_terms: D000062:Accidents, Occupational / Q000517:prevention & control; D000328:Adult; D000704:Analysis of Variance; D005221:Fatigue / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008906:Mining; D009784:Occupational Diseases / Q000175:diagnosis* / Q000503:physiopathology; D017286:Polysomnography; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000503:physiopathology; D011795:Surveys and Questionnaires; D013647:Task Performance and Analysis; D014940:Work Schedule Tolerance