Assessment of a Risk Index for Suicide Attempts Among US Army Soldiers With Suicide Ideation

Abstract

The Department of Veterans Affairs recently began requiring annual suicide ideation (SI) screening of all patients and additional structured questions for patients reporting SI. Related changes are under consideration at the Department of Defense. These changes will presumably lead to higher SI detection, which will require hiring additional clinical staff and/or developing a clinical decision support system to focus in-depth suicide risk assessments on patients considered high risk. To carry out a proof-of-concept study for whether a brief structured question battery from a survey of US Army soldiers can help target in-depth suicide risk assessments by identifying soldiers with self-reported lifetime SI who are at highest risk of subsequent administratively recorded nonfatal suicide attempts (SAs). Cohort study with prospective observational design. Data were collected from May 2011 to February 2013. Participants were followed up through December 2014. Analyses were conducted from March to November 2018. A logistic regression model was used to assess risk for subsequent administratively recorded nonfatal SAs. A total of 3649 Regular Army soldiers in 3 Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) surveys who reported lifetime SI were followed up for 18 to 45 months from baseline to assess administratively reported nonfatal SAs. Outcome was administratively recorded nonfatal SAs between survey response and December 2014. Predictors were survey variables. The 3649 survey respondents were 80.5% male and had a median (interquartile range) age of 29 (25-36) years (range, 18-55 years); 69.4% were white non-Hispanic, 14.6% were black, 9.0% were Hispanic, 7.0% were another racial/ethnic group. Sixty-five respondents had administratively recorded nonfatal SAs between survey response and December 2014. One additional respondent died by suicide without making a nonfatal SA but was excluded from analysis based on previous evidence that predictors are different for suicide death and nonfatal SAs. Significant risk factors were SI recency (odds ratio [OR], 7.2; 95% CI, 2.9-18.0) and persistence (OR, 2.6; 95% CI, 1.0-6.8), positive screens for mental disorders (OR, 26.2; 95% CI, 6.1-112.0), and Army career characteristics (OR for junior enlisted rank, 30.0; 95% CI, 3.3-272.5 and OR for senior enlisted rank, 6.7; 95% CI, 0.8-54.9). Cross-validated area under the curve was 0.78. The 10% of respondents with highest estimated risk accounted for 39.2% of subsequent SAs. Results suggest the feasibility of developing a clinically useful risk index for SA among soldiers with SI using a small number of self-report questions. If implemented, a continuous quality improvement approach should be taken to refine the structured question series.