Abstract
Background: To date, knowledge is limited regarding time-dependent suicide risk in the years following return from deployment and whether such rates vary by military rank (i.e., enlisted, officer) or component (i.e., active duty, National Guard, reserve). To address these gaps in knowledge, the objectives of this study were to determine and compare postdeployment suicide rates and trends (percent change over time), and hazard rates for Army soldiers, by rank and component (measured at the end of the deployment). Methods: Longitudinal cohort study of 860,930 Army soldiers returning from Afghanistan/Iraq deployment in fiscal years 2008-2014 from the Substance Use and Psychological Injury Combat study. Death by suicide was observed from the end of the first deployment in the study period through 2018 (i.e., the most recently available mortality data) for up to 11 years of follow-up. Analyses were conducted in 2021-2022. Results: Adjusting for age, lowest-ranking Junior Enlisted (E1-E4) soldiers had a suicide rate 1.58 times higher than Senior Enlisted (E5-E9)/Warrant Officers (95% CI [1.24, 2.01]) and 2.41 times higher than Officers (95% CI [1.78, 3.29]). Suicide rates among lower-ranking enlisted soldiers remained elevated for 11 years postdeployment. Overall and annual postdeployment suicide rates did not differ significantly across components. Comparisons across rank and component for females were generally consistent with the full cohort results. Conclusions: Lower-ranking enlisted soldiers had the highest rate of suicide, underscoring the importance of understanding rank as it relates to social determinants of health. For over a decade following Afghanistan/Iraq deployment, lower-enlisted rank during deployment was associated with an elevated rate of suicide; thereby suggesting that postdeployment prevention interventions targeting lower-ranking military members are warranted.