Spatial and Environmental Correlates of Prevalence of Treatment for Substance Use Disorders, Retention, and SUD Services Utilization in South Sardinia.

This study explored the economic, social, and spatial correlates of treatment prevalence, retention, and service utilization for substance use disorder (SUD) in South Sardinia. Data from 1,667 patients with an ICD-10 diagnosis of SUD were extracted from the medical records of individuals assisted by three public addiction services in 2019. We used a spatial autoregressive model, a parametric proportional hazard model, and Poisson regression to examine the associations of spatial factors and residents' socioeconomic status with the prevalence of treatment at the census block level, treatment retention, and SUD service utilization at the individual level. The prevalence was higher among residents of areas closer to competent treatment centers, with the worst building conservation status, a lower percentage of high school and university graduates, and a higher percentage of unemployed, divorced, separated, or widowed residents. Men who were older at the time of their first treatment access; primary users of cocaine, cannabis, and alcohol; had higher education level; and who lived far from competent treatment centers and closer to drug trafficking centers interrupted their treatment earlier. Primary heroin users experienced more SUD treatment encounters. Living in economically and socially disadvantaged areas and near treatment facilities was associated with a higher prevalence, whereas living near drug-dealing centers and far from competent treatment centers was associated with a decrease in treatment retention.