The role of race in rural-urban suicide disparities

Purpose To assess the role that race-ethnicity plays in modifying the observed rural-urban disparity in suicide among Veteran Health Administration (VHA) users. Methods We performed a retrospective cohort study of 10,737,864 VHA users between 2003 and 2017, using cross-linked VHA medical records and National Death Index mortality data to assess longitudinal race-stratified rural-urban differences in age- and sex-adjusted annual suicide rates. We used Poisson regression and generated incident rate ratios (IRRs) to formally assess the impact of race on the rural-urban suicide disparity. Given evidence of effect modification, we performed additional race-stratified Poisson regression models. Findings Rurality is significantly associated with a higher risk of suicide in models which do not control for race (IRR = 1.14, 95% CI: 1.10-1.17). However, when race is added to the model, rural residence is no longer significant (0.98, CI: 0.95-1.01). Stratified models demonstrate that rural residence is significantly associated with a higher suicide risk among Hispanic VHA users (1.41, CI: 1.11-1.79), but it is not substantially associated with suicide among White (0.97, CI: 0.94-1.00) and Black (1.03, CI: 0.86-1.23) VHA users. White VHA users have considerably higher suicide rates than Black and Hispanic VHA users, though the suicide rate among Hispanic VHA users, particularly those in rural settings, increased markedly over the period of observation. Conclusions Race significantly modifies the relationship between rural residence and suicide risk. Studies seeking to assess suicide disparity between rural and urban VHA user populations must include adjustment or stratification by race.