A cross-sectional study of seafarers deployed on naval warships in the United States found that workload and uncomfortable mattresses could be targeted against chronic sleep deprivation, according to results published in the Journal of Sleep Research.
The study’s researchers emailed active Surface Force sailors (N = 11,738) to complete a survey on demographics, working conditions, and sleep. They asked participants how many hours of sleep they felt rested, how many hours they sleep at home, how many hours they can sleep on board, and how many hours they sleep on board.
The average reported sleep time on board was 327 (standard deviation [SD], 92) minutes.
The amount of time needed to feel well rested was normally distributed, with the majority requiring about 7 hours of sleep; more mass ranged from 7-9 hours. The distribution of sleeping time determined at home corresponded strongly with the answers to the time required to feel well rested.
The distribution of sleeping accommodations and the sleep actually received on board was distorted, with the sailors having fewer opportunities to sleep on board, so that they felt adequately rested.
No associations were observed between sleep time on board for gender, age, salary grade, time on board, years of service, department, ship class or operating phase. All subgroups received between 71% and 84% of the sleep required to feel well rested.
The strongest correlations between sleep received were between workload (Pearson r, -0.33), required meetings (Pearson r, -0.26), required inspections (Pearson r, -0.25), exercises (Pearson r, – 0.24), uncomfortable mattress (Pearson r, -0.17) and invasive light (Pearson r, -0.15).
This study was limited by its cross-sectional design. In addition, no causal relationships could be established between chronically inadequate sleep on board and the environment.
These data showed that active seafarers did not get enough sleep on board. Optimizing workloads and providing comfortable mattresses can be effective strategies for promoting adequate sleep in the United States Navy.
Russell DW, Markwald RR, Jameson JT. Self-Reported Sleep and Lack of Sleep: Results of a Major Initiative by Sailors attached to US Navy warships. J sleep. 2021; e13397. doi: 10.1111 / jsr.13397