Subjective and objective evaluation of sleep and performance in daytime versus nighttime sleep in extended-hours shift-workers at an underground mine.
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.
Hossain
Jamil L
JL
Sleep Research Laboratory and the Department of Psychiatry, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
Reinish
Lawrence W
LW
Heslegrave
Ronald J
RJ
Hall
Gordon W
GW
Kayumov
Leonid
L
Chung
Sharon A
SA
Bhuiya
Pintu
P
Jovanovic
Dragona
D
Huterer
Nada
N
Volkov
Jana
J
Shapiro
Colin M
CM
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