Table 3. Effect Estimates of Suicide Attempts by Combat Exposure Among Active-Duty Service Members Who Deployed in Support of the Operations in Iraq and Afghanistan (n = 57 841).
| Combat exposurea | Model 1: Unadjusted, HR (95% CI) | Adjusted HR (95% CI) | |
|---|---|---|---|
| Model 2: Adjusted for demographic and military-specific factorsb | Model 3: Adjusted for demographic, military-specific, and mental health factorsc | ||
| Overall | |||
| Any combat experience | |||
| No | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Yes | 1.39 (1.01-1.92)d | 1.14 (0.81-1.62) | 1.02 (0.72-1.44) |
| Combat severity | |||
| No combat: 0 items | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Low combat: 1-3 items | 0.92 (0.62-1.38) | 0.89 (0.59-1.34) | 0.84 (0.56-1.26) |
| Medium combat: 4-7 items | 1.37 (0.93-2.00) | 1.22 (0.81-1.84) | 1.09 (0.72-1.64) |
| High combat: 8-13 items | 2.11 (1.46-3.04)d | 1.77 (1.15-2.72)d | 1.41 (0.91-2.18) |
| Individual combat items | |||
| Feeling in great danger of being killed | 1.51 (1.16-1.98)d | 1.24 (0.93-1.66) | 1.08 (0.81-1.46) |
| Being attacked or ambushed | 1.90 (1.46-2.48)d | 1.71 (1.29-2.27)d | 1.55 (1.16-2.06)d |
| Receiving small arms fire | 1.54 (1.19-1.99)d | 1.30 (0.98-1.72) | 1.17 (0.88-1.56) |
| Clearing/searching homes or buildings | 1.69 (1.28-2.23)d | 1.46 (1.07-1.99)d | 1.32 (0.97-1.81) |
| Having an IED or a booby trap explode near you | 1.83 (1.41-2.37)d | 1.50 (1.13-2.00)d | 1.33 (0.99-1.78) |
| Being wounded or injured | 1.61 (1.14-2.29)d | 1.33 (0.93-1.90) | 1.10 (0.77-1.59) |
| Seeing dead bodies or human remains | 1.69 (1.31-2.18)d | 1.51 (1.14-2.00)d | 1.34 (1.01-1.78)d |
| Handling or uncovering human remains | 1.59 (1.19-2.13)d | 1.35 (0.99-1.84) | 1.17 (0.86-1.61) |
| Knowing someone seriously injured or killed | 1.58 (1.22-2.05)d | 1.31 (0.98-1.76) | 1.17 (0.87-1.57) |
| Seeing Americans seriously injured or killed | 1.52 (1.17-1.96)d | 1.35 (1.03-1.78)d | 1.20 (0.90-1.58) |
| Having a member of your unit seriously injured or killed | 1.55 (1.20-2.00)d | 1.22 (0.91-1.63) | 1.09 (0.81-1.46) |
| Being directly responsible for the death of an enemy combatant | 1.76 (1.26-2.44)d | 1.60 (1.12-2.27)d | 1.38 (0.96-1.98)e |
| Being directly responsible for the death of a noncombatant | 2.68 (1.56-4.61)d | 2.33 (1.34-4.03)d | 1.81 (1.04-3.16)d |
Abbreviations: HR, hazard ratio; IED, improvised explosive device; PTSD, posttraumatic stress disorder.
Each combat exposure was run in a separate model.
A separate model was conducted for each combat exposure as the main exposure, adjusted for age, sex, race/ethnicity, marital status, educational attainment, service branch, and pay grade.
A separate model was conducted for each combat exposure as the main exposure, adjusted for age, sex, race/ethnicity, marital status, educational attainment, service branch, pay grade, and PTSD and/or depression.
P < .05.
Mental health significantly moderated the association of being directly responsible for the death of an enemy combatant with a suicide attempt; therefore, the model was stratified by mental health status. Of the stratified groups, only 1 indicated that being directly responsible for the death of an enemy combatant was significantly associated with increased risk of suicide attempt. Among those with depression only, being directly responsible for the death of an enemy combatant significantly increased the risk of a suicide attempt (adjusted HR, 5.85; 95% CI, 2.26-15.17).