Association Between the ACA Medicaid Expansions and Changes in Cardiovascular Risk Factors Among Low-Income Individuals

Background Evidence is limited as to whether the introduction of the Affordable Care Act (ACA)'s Medicaid expansions was associated with improvements in cardiovascular risk factors at the population level. Objective To examine the association between the ACA Medicaid expansions and changes in cardiovascular risk factors among low-income individuals during the first 3 years of the implementation of the ACA Medicaid expansions at the national level. Design A quasi-experimental difference-in-differences (DID) analysis to compare outcomes before (2005-2012) and after (2015-2016) the implementation of the ACA Medicaid expansions between individuals in states that expanded Medicaid and individuals in non-expansion states. Participants A nationally representative sample of individuals aged 19-64 years with family incomes below 138% of the federal poverty level from the 2005-2016 National Health and Nutrition Examination Survey (NHANES). Intervention ACA Medicaid expansions. Main Measures Cardiovascular risk factors included (1) systolic and diastolic blood pressure, (2) hemoglobin A1c (HbA1c) level, and (3) cholesterol levels (low-density lipoprotein cholesterol, triglyceride, and high-density lipoprotein cholesterol). Key Results A total of 9177 low-income individuals were included in our analysis. We found that the ACA Medicaid expansions were associated with a lower systolic blood pressure (DID estimate, - 3.03 mmHg; 95% CI, - 5.33 mmHg to - 0.73 mmHg; P = 0.01; P = 0.03 after adjustment for multiple comparisons) and lower HbA1c level (DID estimate, - 0.14 percentage points [pp]; 95% CI, - 0.24 pp to - 0.03 pp; P = 0.01; P = 0.03 after adjustment for multiple comparisons). We found no evidence that diastolic blood pressure and cholesterol levels changed following the ACA Medicaid expansions. Conclusion Using the nationally representative data of individuals who were affected by the ACA, we found that the ACA Medicaid expansions were associated with a modest improvement in cardiovascular risk factors related to hypertension and diabetes during the first 3 years of implementation.