LAUSR

On United States Navy (USN) ships, most sailors are shift workers, required to support 24/7 operations. However, ~15% of the ship’s company are solely dayworkers who do not work in shifts. It is often assumed that the quality of life for dayworkers is better than that of shift workers. This study compared the well-being of dayworkers with that of shift workers. Longitudinal, naturalistic observations were made of sailors (N=926; 18-59 years of age, ~80% males, ~84% enlisted personnel) on seven US Navy ships while performing their normal underway duties. Sleep-related attributes (actigraphy, Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Insomnia Severity Index), mood (Profile of Mood States), and work/rest patterns were assessed. Dayworkers (DW; n=98) were on average older (p=0.001) and more senior (p=0.001) than shift workers (SW). Of the dayworkers, 31% reported elevated daytime sleepiness (SW:45.5%; p=0.008), 64.2% were poor sleepers (SW:82.6%; p<0.001), and 26.3% had ISI score≥15 (SW:24.8%; p=0.782). Also, 13.8% of the dayworkers had ESS>10 and ISI≥15 (SW:16.8%; p=0.626).Dayworkers had better mood (Total Mood Disturbance, anger/hostility, vigor, fatigue; all p<0.050), slept more (7.03±0.74hrs sleep/day; SW:6.52±1.03hrs; p<0.001) and had more consolidated sleep (1.1±0.3 sleep episodes/day; SW:1.4±0.6; p<0.001). Yet, split sleep was commonplace for both groups (DW:~62%; SW:~92%).The two groups do not differ (all p>0.300) in their use of caffeinated beverages (82%-86%), use of nicotine products (30%-36%), or having a regular exercise routine (69%-75%). In both groups, ~9% of sailors drank caffeinated beverages, used nicotine products and did not have an exercise routine (p=0.999). Dayworkers worked 10.1 hours/day, i.e., 1.7 hours/day less than watchstanders (p<0.001). Quality of life of dayworkers is a bit better when compared to shift workers, but sleep-related issues are evident in almost all US Navy sailors. Living and working on a naval vessel takes a toll on almost everyone aboard. A culture change is required! Supported by the Naval Medical Research Center’s Advanced Medical Development Program, the US Navy 21st Century Sailor Office, and the US Navy OPNAV N1.