Association Between State Medicaid Eligibility Thresholds and Deaths Due to Substance Use Disorders.

Importance: The United States is currently facing an epidemic of deaths related to substance use disorder (SUD), with totals exceeding those due to motor vehicle crashes and gun violence. The epidemic has led to decreased life expectancy in some populations. In recent years, Medicaid eligibility has expanded in some states, and the association of this expansion with SUD-related deaths is yet to be examined. Objective: To examine the association between eligibility thresholds for state Medicaid coverage and SUD-related deaths. Design, Setting, and Participants: Economic evaluation study using a retrospective analysis of state-level data between 2002 and 2015 to determine the association between the Medicaid eligibility threshold and SUD-related deaths, controlling for other relevant policies, state socioeconomic characteristics, fixed effects, and a time trend. Policy variables were lagged by 1 year to allow time for associations to materialize. Data were collected and analyzed from 2016 to 2017. Exposures: The policy of interest was the state Medicaid eligibility threshold, ie, the highest allowed income that qualifies a person for Medicaid, expressed as a percentage of the federal poverty level. State policies related to mental health, overdose treatment, and law enforcement of drug crimes were included as controls. Main Outcomes and Measures: The primary outcome was number of SUD-related deaths, obtained from data provided by the Centers for Disease Control and Prevention. Results: Across 700 state-year observations, the mean (SD) number of SUD-related deaths was 21.15 (6.05) per 100 000 population. Between 2002 and 2015, the national SUD-related death rate increased from 16.0 to 27.5 per 100 000, while the average Medicaid eligibility threshold increased from 87.2% to 97.1% of the federal poverty level. Over this period, every 100-percentage point increase in the Medicaid eligibility threshold (eg, from 50% to 150% of the federal poverty level) was associated with 1.373 (95% CI, -2.732 to -0.014) fewer SUD-related deaths per 100 000 residents, a reduction of 6.50%. In the 22 states with net contractions in eligibility thresholds between 2005 and 2015, an estimated increase of 570 SUD-related deaths (95% CI, -143 to 1283) occurred. In the 28 states that increased eligibility thresholds, an estimated 1045 SUD-related deaths (95% CI, -209 to 2299) may have been prevented. Conclusions and Relevance: These findings suggest that the overall increase in SUD-related deaths between 2002 and 2015 may have been greater had the average eligibility threshold for Medicaid not increased over this period. Broader eligibility for Medicaid coverage may be one tool to help reduce SUD-related deaths.