Background The relationship between veteran status and firearm suicide has been evaluated previously, but multiple sources of bias limit conclusions. This study aimed to clarify the relationship between a history of military service and firearm suicide.

Methods Data obtained from suicide death certificates from nine states (1999–2009) were analysed. History of military service was validated using data obtained from the Department of Veterans Affairs and Department of Defense. Modified Poisson Regression with robust SEs was used to compute adjusted prevalence ratios for the common outcome of firearm use among suicide decedents.

Results Male veteran suicide decedents were 6% more likely to use firearms, and female veteran suicide decedents were 18% more likely to use firearms compared with their non-veteran peers.

Conclusions Prior estimates based on logistic regression and death certificate reporting of veteran status may have overestimated the relationship between veteran status and firearm use among suicide decedents.