摘要：Objectives. We assessed the risk of suicide among veterans compared with nonveterans. Methods. Cox proportional hazards models estimated the relative risk of suicide, by self-reported veteran status, among 500 822 adult male participants in the National Death Index (NDI)–linked National Health Interview Survey (NHIS), a nationally representative cohort study. Results. A total of 482 male veterans died by suicide during 1 837 886 person-years of follow-up (76% by firearm); 835 male nonveterans died by suicide during 4 438 515 person-years of follow-up (62% by firearm). Crude suicide rates for veterans and nonveterans were, respectively, 26.2 and 18.8 per 100 000 person-years. The risk of suicide was not significantly higher among veterans, compared with nonveterans, after adjustment for differences in age, race, and survey year (hazard ratio = 1.11; 95% confidence interval = 0.96, 1.29). Conclusions. Consistent with most studies of suicide risk among veterans of conflicts before Operation Iraqi Freedom/Operation Enduring Freedom, but in contrast to a previous study using the NDI-linked NHIS data, we found that male veterans responding to the NHIS were modestly, but not significantly, at higher risk for suicide compared with male nonveterans. In 2008, then Secretary of the Department of Veterans Affairs, James Peake, established the Blue Ribbon Working Group on Suicide Prevention to assess suicide risk among the veteran population. 1 The group issued 8 key findings, the first of which was that the literature was contradictory regarding whether veterans were at higher risk for suicide compared with nonveterans. The contradiction was traced to a single survey-based cohort study, published in 2007 by Kaplan et al, 2 which found a greater than 2-fold increased risk of suicide among veterans compared with nonveterans. By contrast, the other studies 3–6 found that suicide risk among veterans as a whole was not higher than that among age-, gender-, and race-matched members of the general population. Kaplan et al.’s study 2 differed in 2 important ways from the other work cited by the Working Group. 3–6 First, Kaplan et al. 2 relied on self-report to assess veteran status, whereas the other studies ascertained veteran status from databases maintained by the Department of Defense. Second, relative risk estimates in Kaplan et al. 2 were based on direct comparisons of suicide incidence among veterans to incidence among nonveterans, whereas other studies used standardized mortality ratios (SMRs) that tended to bias veteran risk toward the null because veterans and nonveterans were both included in the comparison group. Two additional studies were published after the Working Group released its findings. The first, a military cohort study, 7 assessed suicide risk among veterans who served in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) and who separated from the military before 2006 (i.e., before the unprecedented increase in suicide incidence among soldiers). 8 The second study 9 tracked mortality among male respondents in the Cancer Prevention Study. Both studies failed to find evidence of differential suicide risk attributable to veteran status. Our study reexamines the question of whether veterans were at increased risk for suicide using public data from the National Health Interview Survey (NHIS; 1986–2000) that have been linked to the National Death Index (NDI) through 2006—the same data source used in the study by Kaplan et al., 2 now available for several additional years of baseline interviews and mortality follow-up. Like the previous NHIS–NDI study, the present study was limited to pre-OIF/OEF veterans. Because access to firearms is a risk factor for suicide, 10,11 and because veterans are more likely to own firearms than are nonveterans, 12 the present study examined not only the relation between veteran status and overall suicide risk, as did the original NHIS–NDI study, but also whether any such risk was differentially related to firearm versus nonfirearm suicide. Because our primary findings were discrepant with those reported by Kaplan et al., 2 we conducted sensitivity analyses that restricted data to the survey years (1986–1994) and mortality follow-up (through 1997) used in the study by Kaplan et al. 2 Covariates included in these comparative analyses were, by design, the same as those used by Kaplan et al. 2
