The latest such evidence comes from LDI Fellows Paula Chatterjee and Atheendar Venkataramani, who analyzed trends in drug overdose deaths in three states that expanded Medicaid eligibility before the Affordable Care Act (ACA). Arizona, Maine, and New York all expanded Medicaid program eligibility in the early 2000s. The authors found that rates of drug overdose deaths rose less sharply in these states than in all non-expansion states (Figure 1a), as well as in non-expansion, neighboring states (Figure 1b). The pattern held when they adjusted for secular trends and state-specific social policies, such as minimum wage and welfare and food stamp program generosity.
Assessing the relationship between coverage expansion and overdose deaths is challenging in the midst of a national crisis. Drug overdose mortality rates were already increasing prior to implementation of ACA Medicaid expansions in 2014 (the Centers for Disease Control and Prevention declared prescription opioid overdoses an epidemic in 2011). For this reason, Chatterjee and Venkataramani chose to look at earlier expansions, which took place on the eve of the national epidemic. They estimate that from the time of these expansions through 2008, expansion states averaged four (per 100,000 people) fewer deaths from drug overdose annually than non-expansion states.