Trends in Geographic Proximity to Substance Use Disorder Treatment.

INTRODUCTION: This study aims to assess the trends in the number and characteristics of substance use disorder treatment facilities within the county of residence of adults aged 50+ years over time.

METHODS: Using retrospective longitudinal data from the 1992-2018 Health and Retirement Study merged with the county-level data on all licensed treatment facilities in the country, linear mixed models were estimated to calculate geographic accessibility to substance use disorder treatment, adjusted for person-level demographics, state-level controls, and calendar year-fixed effects. Analysis was conducted in 2022.

RESULTS: Overall, older adults experienced a decline in the average number of substance use disorder treatment facilities within their counties of residence from 4.80 per 100,000 residents (95% CI=4.69, 4.92) in 1992 to 4.50 (95% CI=4.35, 4.64) in 2018. However, the number accepting Medicare increased from 0.26 (95% CI=0.21, 0.30) in 1992 to 1.88 (95% CI=1.80, 1.96) facilities per 100,000 (42% of facilities); Medicaid increased from 0.20 (95% CI=0.13, 0.26) in 1992 to 3.50 (95% CI=3.39, 3.62) facilities per 100,000 (78% of facilities) in 2018. Older adults living in more rural areas experienced the most growth in substance use disorder treatment facilities per capita in their counties but with less significant growth in facilities offering medication for opioid use disorder than those living in more urban areas.

CONCLUSIONS: Despite increases in the number of substance use disorder treatment facilities in rural areas, there has been less growth in nearby facilities offering evidence-based medication treatment for opioid use disorder.