Relationships between substance use treatment facilities and alcohol-attributable mortality across US counties

Background: Formal substance use treatment is a key resource for recovery among people with alcohol use disorders. Limited county-level availability of substance use treatment facilities may restrict access to care and ultimately contribute to worsening health outcomes and mortality. However, it is unknown whether the availability of such facilities is associated with county-level alcohol-attributable mortality risk. Methods: We used Bayesian hierarchical Poisson spatial regression models to assess the relationship between population-weighted county-level treatment facility availability and rates of (1) fully chronic alcoholattributable mortality, (2) alcohol poisonings, and (3) suicides by exposure to alcohol in 2019-2020. Localized treatment facility availability was calculated using a weighted method incorporating Census block grouplevel population counts. We adjusted for county-level demographic and socioeconomic factors, hospital density, population density, overall mortality rate, densities of mental health practitioner offices, U.S. Census region, year, and season. Results: There was county-level heterogeneity in the availability of substance use treatment facilities, with northeastern county treatment facility densities at least twice as high as other regions. Higher county-level densities of treatment facilities were related to increased county-level risk for chronic fully alcoholattributable deaths and alcohol poisonings but not suicides by exposure to alcohol. Conclusions: Availability of substance use treatment facilities and the services they offer is heterogeneous across U.S. counties. The positive relationship between population-weighted county-level densities of treatment facilities and chronic fully alcohol-attributable mortality and alcohol poisonings may suggest that treatment facilities are placed in areas of greatest demand; yet, population-level needs may not fully met by these facilities.