Widening Excess Mortality During the COVID-19 Pandemic in Individuals Who Self-Harmed.

Studies on COVID-19 pandemic-associated changes in mortality following self-harm remain scarce and inconclusive. To compare mortality risks in individuals who had self-harmed to those for individuals who had not, before and during the COVID-19 pandemic (Waves 1 and 2) in Wales, the United Kingdom, using population-based routinely collected data. We linked whole population health data to all-cause mortality following an episode of self-harm between April 2016 and March 2021. Propensity score matching, Cox regression, and difference-in-differences were applied to compute changes in excess mortality (as ratios of hazard ratios, RHRs) before and during the pandemic for individuals who self-harmed. The difference in mortality for individuals who self-harmed compared to those who did not widened during Wave 1 (RHR = 2.03, 95% CI: 1.04-4.03) and Wave 2 (RHR = 2.19, 95% CI: 1.12-4.29) from before the pandemic. Stratification by sex and age group produced no significant subgroup differences although risk for younger than 65 years group were higher. Limitations include small sample size and incomplete data on cause-specific deaths during the pandemic. Our results underscore continuous monitoring of mortality of individuals who self-harm and effective interventions to address any increases in mortality.