153EMF The Medicaid Expansion and Racial Disparities in Transfers to Hospitals Capable of Performing Percutaneous Coronary Intervention After Acute Myocardial Infarction

Abstract

Racial disparities in rates of transfer to hospitals capable of performing invasive coronary reperfusion after acute myocardial infarction (AMI) have been previously documented. It is not known to what extent insurance coverage affects these disparities in rates of transfer. The Affordable Care Act (ACA) expanded insurance access to millions of Americans and has had a particular impact on rates of insurance for low-income populations and racial and ethnic minorities. Our objectives were to estimate the effect of the ACA’s Medicaid expansion on racial disparities in rates of transfer to percutaneous coronary intervention (PCI)-capable hospitals for patients admitted with AMI, both non-ST-segment elevation and ST-segment elevation myocardial infarction (NSTEMI and STEMI). We utilized a triple differences approach to compare racial disparities in rates of transfer to PCI-capable hospitals for patients with AMI who initially presented to hospitals without these capabilities in California, a state that expanded Medicaid (through the ACA, statewide, and pre-ACA expansion in certain counties) and Florida, a state that did not, before and after expansion. We used California non-public patient discharge data, hospital financial and utilization data from the California Office of Statewide Health Planning and Development, and Florida state inpatient and emergency department data from the Healthcare Cost and Utilization Project and included all Medicaid and uninsured patients ages 18-64 admitted with AMI from 2010 through 2015. We controlled for comorbidities, sex, age, date of admission, and urbanicity of patient’s home county. Standard errors were clustered at the hospital level. We did not find an association between the Medicaid expansion and changes in the likelihood of transferring to PCI-capable hospitals between white and nonwhite patients who initially presented to non-PCI-capable hospitals with AMI defined as both NSTEMI or STEMI. However, among patients with non-ST-segment myocardial infarction (NSTEMI) who initially presented to hospitals without PCI capabilities, there was a 14 percent increase (95% confidence interval 0.01, 0.28) in likelihood of transfer to a hospital capable of performing these procedures for nonwhite patients compared with white patients. The Medicaid expansion was associated with an increase in the likelihood of transferring to a PCI-capable hospital for nonwhite patients who initially presented to non-PCI-capable hospitals with NSTEMI, relative to white patients. We did not observe the same association when patients with ST-segment myocardial infarction (STEMI) were included in the analyses, potentially because there are clearer treatment guidelines for STEMI, and the treatment of NSTEMI may be more variable and subject to the influence of factors such as insurance coverage.