Sleep Patterns, Mood, Psychomotor Vigilance Performance, and Command Resilience of Watchstanders on the Five and Dime Watchbill.

摘要

This study assesses crew rest and sleep patterns, psychomotor vigilance performance, work demands and rest opportunities, organization commitment, and psychological safety and command resilience of Sailors in the Reactor Department on USS Nimitz (CVN 68) (N = 77) working the 5hrs-on/10hrs-off (5/10) watchstanding schedule. Although crewmembers on the 5/10 received approximately seven hours of sleep per day, they reported experiencing excessive fatigue and dissatisfaction with the schedule. This contradiction is best explained by examining sleep and rest periods over a 72-hour period, during which a crewmember sleeps at three distinctly different time periods each day. On the first day of the cycle, the Sailor typically receives an early-terminated 4-hour sleep episode followed by two periods of sustained wakefulness, 22 and 20 hours. During these periods, daytime napping only partially ameliorates the fatigue and sleep debt accrued during these periods of sustained wakefulness. Given this pattern, it is not surprising that at the end of the underway phase, the crewmembers moods had worsened significantly compared to moods at the beginning of the underway period. Psychomotor vigilance performance in the 5/10 is comparable to the performance of Sailors on the 6hrs-on/6hrs-off (6/6) schedule. It is significantly degraded compared to Sailors on the modified 6hrs-on/18hrs-off (6/18) and the 3hrs-on/9hrs-off (3/9) schedules. Specifically, the 5/10 had 21.4% slower PVT reaction times, and 71.5% more lapses plus false starts than the 3/9. Our findings suggest that the 5/10 watch, combined with other work duties, leads to poor sleep hygiene. Crewmembers on the 5/10 suffer from sustained wakefulness because of extended workdays and circadian-misaligned sleep times. In general, the self-reported survey results suggest low degrees of resilience, psychological commitment to the organization, and psychological safety.