Operational assessment of the 5-h on/10-h off watchstanding schedule on a US Navy ship: sleep patterns, mood and psychomotor vigilance performance of crewmembers in the nuclear reactor department

Ergonomics ◽  
2015 ◽  
Vol 59 (5) ◽  
pp. 657-664 ◽  
Author(s):  
Nita Lewis Shattuck ◽  
Panagiotis Matsangas
Author(s):  
Anna Sjörs Dahlman ◽  
Panagiotis Matsangas ◽  
Nita Lewis Shattuck

As part of a broader study, this work investigates if habitual exercise protects against mood deterioration and daytime sleepiness in Sailors during underway operations. Previous work has shown that unfavorable watchstanding schedules have negative effects on sleep quality, subjective levels of fatigue, mood, and psychomotor vigilance performance. The participants were crewmembers of a U.S. Navy aircraft carrier (N=193), working on two different watchstanding schedules. Epworth Sleepiness Scale (ESS) and profile of mood state (POMS) scores were compared between participants who reported exercising < 3 times/week and ≥3 times/week. During the course of the underway, ESS and POMS scores changed more favorably for the crewmembers who exercised 3 or more times/week compared to their peers who exercised less. The effect of working out was more prominent in the less favorable shift schedule. These results suggest that habitual exercise can be a protective buffer against some of the negative effects of watchstanding while underway.


SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A313-A313
Author(s):  
N L Shattuck ◽  
P Matsangas

Abstract Introduction Approximately 18% of US Navy sailors are females. Research has shown gender-related differences in the prevalence of sleep disorders in active duty personnel (Foster et al., 2017). Specifically, insomnia, depression, and anxiety are more prevalent in females, while obstructive sleep apnea is more prevalent in males. We have studied the sleep patterns and fatigue levels of crew members on more than 30 US Navy ships. The current study focuses on gender differences in well-being, sleep-related behaviors, and psychomotor vigilance performance of sailors in the US Navy. Methods Using a longitudinal, naturalistic observation paradigm, data were collected from crewmembers on nine USN ships while performing their normal underway duties. Participants (N=1,056) tended to be young (on average 27 years of age), predominantly male (80.6%), and enlisted (84.8%). We assessed average daytime alertness (Epworth Sleepiness Scale), insomnia symptoms (Insomnia Severity Index), mood (Profile of Mood States), and sleep quality (Pittsburgh Sleep Quality Index). Sleep was assessed with actigraphy and logbooks. Sailors performed a 3-minute version of the Psychomotor Vigilance Task (PVT), which was built into their wrist-worn actigraph. Results Compared to males, female sailors reported more depressive symptoms (p=0.042) and less vigor (p&lt;0.001). Females slept more (daily sleep duration: p&lt;0.001) but their sleep was split into more episodes than their male counterparts (p=0.029). Fewer females reported a regular exercise routine (p=0.033). In addition, females report consuming fewer energy drinks (p=0.007), and using fewer nicotine products (p=0.013). Lastly, consistent with findings from civilian populations, female sailors had slower reaction times on the PVT (p&lt;0.001) and experienced more lapses combined with false starts (p&lt;0.001) than their male counterparts. Conclusion Compared to their male peers, female sailors tend to report higher levels of depression and lower levels of vigor. They experience more pronounced split sleep, are less likely to report having an exercise routine, and have poorer performance on the PVT. Fewer females report using energy drinks and nicotine products. Support This research was 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.


Author(s):  
Jillian Dorrian ◽  
Naomi Rogers ◽  
David Dinges

SLEEP ◽  
2020 ◽  
Vol 43 (12) ◽  
Author(s):  
Panagiotis Matsangas ◽  
Nita Lewis Shattuck

Abstract Study Objectives This field study (a) assessed sleep quality of sailors on the U.S. Navy (USN) ships while underway, (b) investigated whether the Pittsburgh Sleep Quality Index (PSQI) scores were affected by occupational factors and sleep attributes, and (c) assessed whether the PSQI could predict impaired psychomotor vigilance performance. Methods Longitudinal field assessment of fit-for-duty USN sailors performing their underway duties (N = 944, 79.0% males, median age 26 years). Participants completed questionnaires, wore actigraphs, completed logs, and performed the wrist-worn 3-min Psychomotor Vigilance Task (PVT). Results Sailors slept on average 6.60 ± 1.01 h/day with 86.9% splitting their sleep into more than one episode/day. The median PSQI Global score was 8 (interquartile range [IQR] = 5); 80.4% of the population were classified as “poor sleepers” with PSQI scores &gt;5. PSQI scores were affected by sailor occupational group, rank, daily sleep duration, and number of sleep episodes/day. Sleep quality showed a U-shape association with daily sleep duration due to the confounding effect of split sleep. Sailors with PSQI scores &gt;9 had 21.1% slower reaction times (p &lt; 0.001) and 32.8%–61.5% more lapses combined with false starts (all p &lt; 0.001) than sailors with PSQI scores ≤9. Compared to males and officers, females and enlisted personnel had 86% and 23% higher risk, respectively, of having PSQI scores &gt;9. Sailors in the PSQI &gt; 9 group had more pronounced split sleep. Conclusions Working on Navy ships is associated with elevated PSQI scores, a high incidence of poor sleep, and degraded psychomotor vigilance performance. The widely used PSQI score&gt;5 criterion should be further validated in active-duty service member populations.


SLEEP ◽  
2018 ◽  
Vol 41 (suppl_1) ◽  
pp. A229-A229
Author(s):  
P SAINI ◽  
E Bremer ◽  
S Broyles ◽  
D Rye ◽  
L Trotti

2006 ◽  
Vol 168 (2) ◽  
pp. 312-317 ◽  
Author(s):  
Katharina Blatter ◽  
Peter Graw ◽  
Mirjam Münch ◽  
Vera Knoblauch ◽  
Anna Wirz-Justice ◽  
...  

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