Substitution of Methods in Suicide Deaths - Firearm Injury and Hanging.

Background: Prevention strategies for suicide emphasize restrictions on firearm access. These restrictions may lose efficacy if individuals substitute other lethal suicide methods. Aims: The objective of this study is to determine the extent to which individuals who die by suicide in the United States substitute hanging for firearm injury. Methods: This study is a repeated cross-sectional analysis of suicide deaths in the United States from 2003 to 2021. Multiple regression was used to estimate the effect of firearm access proxies on individual suicide methods (hanging vs. firearm injury). Results: The probability of death by hanging was significantly and negatively associated with proxies of firearm access. Limitations: This study does not compare crude rates of suicide by state, which rise on average with rates of firearm ownership. The National Violent Death Reporting System expanded over the sample period, so early years have incomplete ascertainment. Rates of gun ownership and gun safety law scales are measured as proxies. Conclusions: Although means restriction around firearm access is a critical tool for suicide prevention, complementary strategies for prevention around hanging merit further study.