Medicaid Expansion Impact on Cardiovascular Mortality Rates

A recent observational study has found that counties in state that expanded Medicaid had significantly smaller increases in cardiovascular mortality rates compared to nonexpansion states.

The study compared cardiovascular mortality rates among adults between the ages of 45 and 64 in expansion and nonexpansion states and found that counties in expansion states had a median of 4.3 fewer deaths per 100,000 than nonexpansion states.

Using the Centers for Disease Control and Prevention’s Wide-ranging Online Data for Epidemiologic Research to obtain cardiovascular mortality rates in individuals 45 to 64 years of age from 2010 to 2016 from all 50 states and Washington DC. Investigators obtained data on percentages of residents who were female, black, Hispanic, living in poverty, and unemployed form the US Census Bureau and the Bureau of Labor Statistics. Investigators also obtained the median inflation adjusted income.

The primary outcome for the study was county-level, age-adjusted cardiovascular mortality rates per 100,000 adults in the study age group. For sensitivity measures, investigators also examined rates among residents between the ages of 25 and 64 and the ages of 65 and 74.

The main intervention within the study was the expansion of Medicaid eligibility under the Affordable Care Act in 2014. Investigators did not include Michigan, New Hampshire, Pennsylvania, Indiana, Alaska, and Montana within their analysis due to a later expansion of Medicaid. Due to previous eligibility expansion in Massachusetts and coverage of up to 100% of the FPL population in Wisconsin, these 2 states were excluded from the main analysis. California, Connecticut, the District of Columbia, Minnesota, New Jersey and Washington were excluded from the main analysis because of limited expansions prior to 2014 — Authors noted that these states, along with the 6 late-adopters were included in the sensitivity analysis, despite being excluded from the main analysis.

Investigators designated 2010 through 2013 as the preexpansion period and 2014 through 2016 were used as the post expansion period. In states where expansion occurred later, the period began in the year expansion was implemented.

Investigators included counties in 29 expansion states plus the District of Columbia in the intervention group and counties in 19 nonexpansion states in the control group. A total of 79.7 million middle-aged adults were included in the study. The number of counties included ranged between 902 to 931 in the expansion group and between 985 and 1029 for the nonexpansion group. Counties with fewer that 10 deaths per year (less than 5%) were censored from the analysis.

The age-adjusted cardiovascular mortality rates for residents aged 45 to 64 were significantly lower in counties in expansion states compared with counties in nonexpansion states between 2010 (147.9 versus 177.6 deaths per 100,000 each year) and 2013 (145.6 versus 177.8 deaths per 100,000), Authors added that trends between these groups were similar. Accounting for differences in covariates significantly reduced the differences between the two groups. Counties in expansion states had a mean of 4.3 fewer deaths per 100,000 residents than they would have had they followed the same trends as counties in nonexpansion states.

Authors noted several limitations within their study. They were unable to make a causal association between expansion and differences in cardiovascular mortality rates between the 2 groups of counties. Despite the target of Medicaid expansion being low income adults, the study’s outcome measured all income categories. Investigators did not analyze individual disease to explain which were driving the overall mortality trend.

Based on the results of the study, authors suggest that policymakers need to further debate for additional changes to the eligibility and expansion of Medicaid.

The study, titled “Association of Medicaid Expansion With Cardiovascular Mortality,” is published in JAMA Cardiology.