Association for Public Policy Analysis & Management

The Affordable Care Act expanded access to health insurance for low-income populations during a time of rising rates of societal concerns regarding substance-use disorders (SUDs) and related health consequences. For example, from 2002 to 2015, the number of US deaths due to drug overdoses increases 220 percent (CDC, 2017). Access to health insurance is a necessary setting for providing meaningful solutions to adverse health consequences from SUDs, but it is unclear whether coverage is sufficient, given the difficulties in access to highly effective treatment methods, as well as non-health care-amenable reasons for SUDs. In this research, we exploit cross-state variation in adoption of the ACA Medicaid expansion in 2014 as the main source of variation. We also compare outcomes for the affected age range (19-64) relative to those who are older or younger. We also use within-state variation in the degree of the expansion in coverage (e.g. across counties with low and high uninsurance rates prior to the ACA), to examine the effect of health insurance coverage on SUDs overdose related deaths and emergency department (ED) visits.

Our source of data for SUD death rates (both opioid and non-opioid related, including heroin related) is the National Vital Statistics System of the Centers for Disease Control and Prevention Multiple Cause of Death (MCOD). We use data from 1999-2015, allowing us to assess death rates upto two years post expansion. Our data on Emergency Department come from the Healthcare Cost and Utilization Project (HCUP)’s State Emergency Department Database (SEDD) at the county level for 5 states and at the state level for 15 states. We create population-level rates of adverse outcomes by dividing the state or county based totals by the population estimates.

Our method of inquiry is to test whether the rate of SUDs deaths (and overdose ED visits) decreased after vs before Medicaid expansion, in Medicaid expansion states vs non-expanding states. We also examine whether decreases in deaths and adverse events are greater in age ranges (19-64 vs others), geographical areas (counties), and socio-economic groups (by educational attainment and race) more affected by the expansion.