Abstract 9257: The Effect of Massachusetts Health Reform on Racial Disparities in 30-Day Readmissions for Acute Myocardial Infarction
Background: Following Massachusetts (MA) health reform, the percent of uninsured residents fell from 8.4% to 3.4%, with larger gains among minorities. Prior studies have not examined the effect of this policy change on 30-day readmission rates for myocardial infarction (MI). We hypothesized that racial disparities in such admissions would decline in MA among adults age 18-64 following the reform.
Methods: Using MA inpatient discharge data from 2004-2009, we compared 30-day readmissions after hospitalization for acute MI among white and black patients, prior to and following reform implementation. We defined the pre-reform period as 2004-2006, and the post-reform period as 2008-2009. We used chi-square tests to compare 30-day readmissions for MI between groups. Controlling for age, gender, and Charlson Comorbidity Score, we used multiple logistic regression to calculate risk-adjusted odds of 30-day readmission. Treating adults > 65 (who are mostly covered by Medicare and thus unaffected by the reform) as the comparison cohort, we used difference-in-difference specification to identify the post-reform change adjusted for secular changes unrelated to reform.
Results: Pre-reform, black patients age 18-64 had higher readmission rates than white patients (18.1% vs. 11.2%; p=0.001), this difference persisted post-reform (17.0% vs. 10.2%; p <0.001). Among patients age ≥65, in the pre-reform period, black patients also had higher readmission rates than whites (29.2% vs. 23.9%; p=0.02); this also persisted post-reform (27.8% vs. 22.2%; p=0.01). The readmission rate for blacks age18-64 did not change significantly from pre-reform to post-reform (18.1% vs. 17.0%, adjusted OR (AOR), 0.9; 95% CI, 0.6- 1.3); nor did the readmission rate for blacks, age ≥65, change significantly (29.2% vs. 27.8%, AOR, 0.8; 95% CI, 0.6- 1.2). The difference in the change in AOR for blacks pre- and post- reform, age 18-64, and the change in AOR for blacks pre- and post- reform, age > 65 (“difference-in-difference”) was not significant (p=0.6).
Conclusions: Black patients were more likely than whites to be readmitted after hospitalization for MI, both before and after health reform. MA health reform had no measurable impact on disparities in 30-day readmissions for MI.
- © 2011 by American Heart Association, Inc.