The contribution of method choice to gender disparity in suicide mortality: A population-based study in Hong Kong and the United States of America

Background: In most countries, more females than males attempt suicide, yet suicide mortality is typically higher for males. The aim of this study was to investigate how suicide method choice contributed to gender disparity in suicide mortality. Methods: This study used population-based data collected in Hong Kong (HK) and the United States of America (USA) (2007-2014), comprising suicide deaths and medically treated suicide attempts. We calculated suicide rates, suicide act rates, and case fatality rates (CFRs), by gender and suicide method in HK and the USA respectively. Decomposition analysis was used to quantify the contribution of gender differences in method choice and method-specific CFRs to the excess male suicide rates in each region. Results: Gender disparity in suicide mortality was mostly driven by gender differences in method used in suicide acts. In HK, gender difference in choosing jumping as the method in suicide acts explained 44.5% of the gender imbalance in suicide rates, whilst in USA, 62.4% of male excess in suicide rates was explained by gender difference in using firearms in suicide acts. Limitations: Cases of suicide attempts in this study were restricted to those severe enough to require medical attention. Conclusion: Gender-specific suicide method choice largely determined gender patterns in suicide. Our findings highlighted the importance of developing locally tailored suicide prevention strategies targeting commonly used and highly lethal suicide methods. Future research is needed to explore underlying reasons for gender differences in method choice.