Abstract 117: Massachusetts Health Care Reform Reduced Racial/Ethnic Disparities in Elective Percutaneous Coronary Intervention and Coronary Artery Bypass Graft Surgery

Abstract

Objective: Percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) are documented to be used less often among racial/ethnic minorities. Insurance coverage expansions, such as the 2006 Massachusetts (MA) reform and the 2010 Affordable Care Act, have the potential to reduce disparities in access to health care. Using the quasi-experimental setting of MA reform, we examined the causal impact of coverage expansion on disparities in use of elective and non-elective PCI and CABG. Study Design: We applied a difference-in-differences design for adults aged 40 to 64 (those most at risk for these procedures among the target beneficiaries of reform) stratified by race/ethnicity (Whites, Blacks and Hispanics). We estimated population rates of procedure use (# procedures per 100,000 census population) during the 2 years prior to the start of reform (7/1/2006) and the 2 years following coverage expansion (1/1/2008). To isolate the impact of reform, we adjusted for secular changes unrelated to reform based on a comparison of the pre-post change in the target subpopulation (MA residents aged 40 to 64) with corresponding changes among (a) residents of three comparison states (New Jersey, New York and Pennsylvania) aged 40 to 64, and (b) residents of MA aged 65 and older. We obtained counts of elective and non-elective PCI and CABG procedures from 2004-2010 state discharge data. Population counts were obtained from the census data files. Stratifying the population by race/ethnicity, age and sex, we estimated Poisson regression models with fixed effects for state and time. Findings: During the pre-reform period the total combined numbers of elective PCI and CABG procedures, by race/ethnicity, were: 11,919 (Whites), 227 (Blacks) and 251 (Hispanics). Pre-reform procedure rates (# procedures per 100,000) were significantly lower among Blacks (71) and Hispanics (80) compared to Whites (139). There was a secular decrease in overall rates of elective PCI and CABG, with a larger decrease among the target cohort of MA residents aged 40 to 64 (-41%) than among comparison-state residents aged 40-64 (-28%) and MA residents aged 65 and older (-32%). Adjusted for secular trends, MA reform was associated with an increase in elective procedures among Blacks (7%, 95% confidence interval [CI]=[3%, 11%]) and Hispanics (4%, 95% CI=[2%, 6%]), but a decrease among Whites (-7%, 95% CI=[-8%, -6%]). For non-elective PCI and CABG procedures, MA reform was associated with no change among Whites, Blacks and Hispanics. Conclusion: MA health reform may have increased the use of elective PCI and CABG among Blacks and Hispanics, thereby indicating possible improved access to outpatient care and reduction of disparities. Implications: Despite a sizable secular decrease in procedure use among all subpopulations, procedure use may have increased among minority groups with previously unmet need or with newly identified need.