Presentation
Sailors’ adaptation to night work with fixed and rotating duty times - first evidence from a sea trial.
SessionLBR2: Late-Breaking Results
DescriptionIn rotating watch schedules, duty times of sailors change from day to day so sailors can take turns in standing watch during unphysiological night times. The downside is that the sailors have to adapt to different times for work and rest each day. Vice versa, fixed schedules allow to get used to daily recurring work and rest times. But it is an open question whether humans can adapt to constant night work at sea.
Land-based studies of shift work show that most workers cannot adapt to permanent night shifts, and thus, rotating shifts are recommended. In military seafaring, rotating schedules are common, but recent guidelines recommend fixed schedules, which are standard in merchant shipping.
To determine the effects of fixed and rotating schedules on sailors, we conducted a sea trial in an A-B-B-B-A design aboard a German Frigate, collecting data regarding subjective sleepiness and fatigue, psychomotor vigilance performance and actigraphy in a rotating (A) and a fixed (B) 3-section watch schedule.
First LMM data analyses (N=80) for sleepiness, assessed daily at each watch turnover with the Karolinska Sleepiness Scale, revealed an interaction of daytime and schedule, (β=-0.08, t(1371)=-1.906, p=.057) indicating similar levels of sleepiness during daytime in the rotating (M=4.39,SE=0.23) and the fixed schedule (M=4.43,SE=0.16). During nighttime, higher sleepiness was reported in the rotating (M=6.12,SE=0,23) than in the fixed schedule (M=5.82,SE=0.17). This is the first direct evidence that aboard a ship, adaptation to night work may be better with constant than with rotating duty times.
Land-based studies of shift work show that most workers cannot adapt to permanent night shifts, and thus, rotating shifts are recommended. In military seafaring, rotating schedules are common, but recent guidelines recommend fixed schedules, which are standard in merchant shipping.
To determine the effects of fixed and rotating schedules on sailors, we conducted a sea trial in an A-B-B-B-A design aboard a German Frigate, collecting data regarding subjective sleepiness and fatigue, psychomotor vigilance performance and actigraphy in a rotating (A) and a fixed (B) 3-section watch schedule.
First LMM data analyses (N=80) for sleepiness, assessed daily at each watch turnover with the Karolinska Sleepiness Scale, revealed an interaction of daytime and schedule, (β=-0.08, t(1371)=-1.906, p=.057) indicating similar levels of sleepiness during daytime in the rotating (M=4.39,SE=0.23) and the fixed schedule (M=4.43,SE=0.16). During nighttime, higher sleepiness was reported in the rotating (M=6.12,SE=0,23) than in the fixed schedule (M=5.82,SE=0.17). This is the first direct evidence that aboard a ship, adaptation to night work may be better with constant than with rotating duty times.
Event Type
Late Breaking Results
TimeWednesday, September 11th3:40pm - 3:50pm MST
LocationFLW Salon B