A national cohort study of the association between the polytrauma clinical triad and suicide-related behavior among US veterans who served in Iraq and Afghanistan

Objectives. We examined the association of posttraumatic stress disorder (PTSD), traumatic brain injury, and chronic pain-the polytrauma clinical triad (PCT)-independently and with other conditions, with suicide-related behavior (SRB) risk among Operation Enduring Freedom (OEF; Afghanistan) and Operation Iraqi Freedom (OIF) veterans. Methods. We used Department of Veterans Affairs (VA) administrative data to identify OEF and OIF veterans receiving VA care in fiscal years 2009-2011; we used International Classification of Diseases, Ninth Revision, Clinical Modification codes to characterize 211 652 cohort members. Descriptive statistics were followed by multinomial logistic regression analyses predicting SRB. Results. Co-occurrence of PCT conditions was associated with significant increase in suicide ideation risk (odds ratio [OR] = 1.9; 95% confidence interval [CI] = 1.5, 2.4) or attempt and ideation (OR = 2.6; 95% CI = 1.5, 4.6), but did not exceed increased risk with PTSD alone (ideation: OR = 2.3; 95% CI = 2.0, 2.6; attempt: OR = 2.0; 95% CI = 1.4, 2.9; ideation and attempt: OR = 1.8; 95% CI = 1.2, 2.8). Ideation risk was significantly elevated when PTSD was comorbid with depression (OR = 4.2; 95% CI = 3.6, 4.8) or substance abuse (OR = 4.7; 95% CI = 3.9, 5.6). Conclusions. Although PCT was a moderate SRB predictor, interactions among PCT conditions, particularly PTSD, and depression or substance abuse had larger risk increases.