Risk Factors Associated With Attempted Suicide Among US Army Soldiers Without a History of Mental Health Diagnosis

Abstract

Importance: The US Army suicide attempt rate increased sharply during the wars in Afghanistan and Iraq. Although soldiers with a prior mental health diagnosis (MH-Dx) are known to be at risk, little is known about risk among those with no history of diagnosis.

Objective: To examine risk factors for suicide attempt among soldiers without a previous MH-Dx.

Design, setting, and participants: In this retrospective longitudinal cohort study using administrative data from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS), person-month records were identified for all active-duty Regular Army enlisted soldiers who had a medically documented suicide attempt from January 1, 2004, through December 31, 2009 (n = 9650), and an equal-probability sample of control person-months (n = 153 528). Data analysis in our study was from September 16, 2017, to June 6, 2018. In a stratified sample, it was examined whether risk factors for suicide attempt varied by history of MH-Dx.

Main outcomes and measures: Suicide attempts were identified using Department of Defense Suicide Event Report records and International Classification of Diseases, Ninth Revision, Clinical Modification E95 × diagnostic codes. Mental health diagnoses and related codes, as well as sociodemographic, service-related, physical health care, injury, subjection to crime, crime perpetration, and family violence variables, were constructed from Army personnel, medical, legal, and family services records.

Results: Among 9650 enlisted soldiers with a documented suicide attempt (74.8% male), 3507 (36.3%) did not have a previous MH-Dx. Among soldiers with no previous diagnosis, the highest adjusted odds of suicide attempt were for the following: female sex (odds ratio [OR], 2.6; 95% CI, 2.4-2.8), less than high school education (OR, 1.9; 95% CI, 1.8-2.0), first year of service (OR, 6.0; 95% CI, 4.7-7.7), previously deployed (OR, 2.4; 95% CI, 2.1-2.8), promotion delayed 2 months or less (OR, 2.1; 95% CI, 1.7-2.6), past-year demotion (OR, 1.6; 95% CI, 1.3-1.8), 8 or more outpatient physical health care visits in the past 2 months (OR, 3.3; 95% CI, 2.9-3.8), past-month injury-related outpatient (OR, 3.0; 95% CI, 2.8-3.3) and inpatient (OR, 3.8; 95% CI, 2.3-6.3) health care visits, previous combat injury (OR, 1.6; 95% CI, 1.0-2.4), subjection to minor violent crime (OR, 1.6; 95% CI, 1.1-2.4), major violent crime perpetration (OR, 2.0; 95% CI, 1.3-3.0), and family violence (OR, 2.9; 95% CI, 1.9-4.4). Most of these variables were also associated with suicide attempts among soldiers with a previous MH-Dx, although the strength of associations differed.

Conclusions and relevance: Suicide attempt risk among soldiers with unrecognized mental health problems is a significant and important challenge. Administrative records from personnel, medical, legal, and family services systems can assist in identifying soldiers at risk.

Figure.. Standardized Risk of Suicide Attempt by Number of Days With an Outpatient Physical Health Care Visit in the Past 2 Months Among Regular Army Enlisted Soldiers With and Without a History of Mental Health Diagnosis

The sample of Regular Army enlisted soldiers (9650 cases [153 528 control person-months]) is a subset of the total Regular Army sample (193 617 person-months) from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) Historical Administrative Data Study. Control person-months were assigned a weight of 200 to adjust for undersampling. The standardized risk estimate (SRE) (number of soldiers with a suicide attempt per 100 000 person-years) was calculated assuming that other predictors were at their samplewide means. The SREs were calculated using a logistic regression analysis that adjusted for sociodemographics (sex, current age, race/ethnicity, education, and marital status) and service-related variables, including age at Army entry, time in service (1, 2, 3-4, 5-10, or >10 years), deployment status (never, currently, or previously deployed), delayed promotion, demotion, and military occupation (combat arms, special forces, combat medic, or other). The model also included a dummy predictor variable for calendar month and year to control for secular trends.