0229 Examining Changes in Subjective Sleep Quality among U.S. Army Tankers Before and During a Mission Readiness Training Exercise

Sustained sleep restriction associated with military operations results in a large sample of individuals who present with insomnia-like symptoms. While units deploy and train together, unit hierarchy can result in group differences. Studying active-duty Soldiers presents the unique opportunity to examine how this organization can influence sleep in the larger group. In this analysis, we examine the variance in subjective sleep quality between groups. 246 tankers from battalions within a brigade participated in a study planned around a mission readiness training exercise. Crewmen completed a baseline (T1) and retrospective (T2) survey capturing subjective sleep quality. Insomnia Severity Index (ISI) scores and subjective sleep duration from the Pittsburgh Sleep Quality Index (PSQI) were analyzed. Battalion differences within the brigade were tested using t-tests and analysis of variance (ANOVA). For sleep duration, Soldiers reported sleeping significantly less hours per night (M=4.98, SE=0.23) at T2 compared to T1 (M=5.59, SE=0.10), t (118) = 2.52, p= 0.013. At the battalion level, there was a significant interaction for sleep duration, F (3, 115) = 6.34, p=0.001. Battalions W, Y, and Z reported sleeping significantly less at T2 compared to T1. Conversely, Battalion X reported sleeping significantly less at T1 than T2. ISI severity of all crews indicated subthreshold insomnia, in which Soldiers reported significantly more sleep problems at T2 (M=13.25, SE=0.89) than T1 (M=10.25, SE=0.72), t (143) = -2.98, p= 0.005. Additionally, there was a significant interaction for the ISI among battalions, F (3, 40) = 3.34, p=0.03. Battalions W, Y, and Z reported significantly more sleep problems at T2 than T1. Battalion X reported significantly more sleep problems at T1 than T2. Across the unit, tank crews reported restricted sleep and subthreshold insomnia symptoms prior to as well as during training despite battalion group differences. It is possible that sleep quality may impact mental health, group dynamics, leadership, and unit culture. Department of Defense Military Operational Medicine Research Program (MOMRP).