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

摘要

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. The mental health of service members and veterans has been an issue of growing concern since the beginning of the US conflicts in Iraq and Afghanistan, 1–5 with marked increases in the incidence of psychological disorders among veterans accompanied by a corresponding increase in suicides and suicide-related behavior (SRB). 6,7 Although suicide has historically been lower among service members than members of the general population (the so-called healthy warrior effect), 8 suicide rates among both service members and younger veterans have been on the increase during Operation Enduring Freedom (OEF; Afghanistan) and Operation Iraqi Freedom (OIF). 9,10 Although Kang and Bullman 8 found in 2008 that suicide risk was not significantly higher among OEF and OIF veterans compared with the US population as a whole, they did identify an elevated suicide rate among former active duty service members and those diagnosed with mental disorders, suggesting the presence of vulnerable subgroups within this population. It was recently estimated that some 22 veterans died by suicide every day in 2010 11 and both the Department of Defense and the Department of Veterans Affairs (VA) have identified suicide prevention as a key priority in ongoing initiatives. 12 Among the risk factors for suicide among veterans, the most predictive appear to be previous history of suicide attempt 13 or previous diagnosis of psychiatric disorders including posttraumatic stress disorder (PTSD), depression, substance abuse, bipolar disorder, and schizophrenia. 14–17 Approximately one fifth of OEF or OIF veterans seeking care within VA have been diagnosed with PTSD. 18 Although the increase in suicide risk associated with PTSD may be smaller than for other psychiatric diagnoses, 16,19 PTSD appears to predict increased suicide ideation in both veterans 6,20 and nonveterans. 21 Jakupcak et al. 19 have found that veterans with even subthreshold PTSD are at increased risk for suicide ideation. Like PTSD, traumatic brain injury (TBI) has also been associated with increased suicide ideation and attempts as well as completed suicides, 6,22,23 and may be associated with damage to the frontal lobe that can increase impulsivity and suicidality. 24 Incidence of TBI has gone up sharply over the past decade, 25 and high comorbidity between TBI and PTSD has often made it difficult to distinguish their unique effects on suicide risk. At least 1 study found that TBI of any severity is associated with an increased rate of completed suicides among veterans that is not accounted for by psychiatric comorbidity 22 ; others have reported increased suicide risk among military personnel with TBI when assessed within a few days of their injuries. 26 More recent evidence indicates that military personnel who have experienced multiple TBIs are at incrementally increased risk for suicidality even when the study controlled for PTSD and depression severity. 23 By contrast, studies by Barnes et al. 6 and Skopp et al. 27 have reported that mild TBI does not significantly increase risk of suicide ideation or intent among active duty service members or veterans with PTSD, suggesting that there is room for additional clarification of TBI and its role in affecting SRBs. Alongside these signature injuries of the wars in Iraq and Afghanistan, studies also identify high rates of chronic pain among OEF and OIF veterans. 28–31 The co-occurrence of PTSD, TBI, and chronic pain, affecting as many as 42% of those receiving polytrauma care, has come to be known as t