Shorter- and Longer-Term Risk for Suicide Among Male US Military Veterans in the Year After Discharge From Psychiatric Hospitalization

Objective: Risk for suicide is highest in the first 3 months (days 1-90) after discharge from acute psychiatric hospitalization yet remains elevated for the remainder of the year (days 91-365). The purpose of this study was to compare risk factors for suicide in the first 90 days to those over the remainder of the year to identify changes across time frames. Methods: The study included 316,707 male veterans discharged from Veterans Health Administration acute psychiatric inpatient units from 2008 through 2013. Proportional hazard regression models were used to identify predictors of suicide death in the first 90 days and in days 91-365, defined via ICD-10 codes. Adjusted piecewise proportional hazard regression was used to compare risk across time frames. Results: Among the 1,037 veterans (< 1%) who died by suicide, 471 (45%) died between days 1 and 90 and 566 (55%) died between days 91 and 365. There was little change regarding the strength of risk factors over time, with two exceptions: risk increased among those aged 18-29 years compared to those aged >= 65 years (days 1-90: hazard ratio [HR] = 0.83; 95% CI, 0.57-1.20 vs days 91-365: HR = 1.42; 95% CI, 1.03-1.97; P < .05), whereas, risk associated with suicidal ideation decreased (days 1-90: HR = 1.89; 95% CI, 1.57-2.28 vs days 91-365: HR = 1.40; 95% CI, 1.17-1.66, P < .05). Conclusions: The strength of association between common risk factors and suicide remains relatively stable during the year following psychiatric hospitalization. However, risk among veterans aged 19-29 years increased over time, whereas risk among those with suicidal ideation decreased.