Massachusetts Reform and Disparities in Inpatient Care Utilization

Background: The 2006 Massachusetts health reform substantially decreased uninsurance rates. Yet, little is known about the reform's impact on actual health care utilization among poor and minority populations, particularly for receipt of inpatient surgical procedures that are commonly initiated by outpatient physician referral. Methods: Using discharge data on Massachusetts hospitalizations for 21 months before and after health reform implementation (7/1/2006-12/31/2007), we identified all nonobstetrical major therapeutic procedures for patients aged 40 or older and for which >= 70% of hospitalizations were initiated by outpatient physician referral. Stratifying by race/ethnicity and patient residential zip code median (area) income, we estimated prereform and postreform procedure rates, and their changes, for those aged 40-64 (nonelderly), adjusting for secular changes unrelated to reform by comparing to corresponding procedure rate changes for those aged 70 years and above (elderly), whose coverage (Medicare) was not affected by reform. Results: Overall increases in procedure rates (among 17 procedures identified) between prereform and postreform periods were higher for nonelderly low area income (8%, P = 0.04) and medium area income (8%, P < 0.001) cohorts than for the high area income cohort (4%); and for Hispanics and blacks (23% and 21%, respectively; P < 0.001) than for whites (7%). Adjusting for secular changes unrelated to reform, postreform increases in procedure utilization among nonelderly were: by area income, low = 13% (95% confidence interval (CI) = [9%, 17%]), medium = 15% (95% CI [6%, 24%]), and high = 2% (95% CI [-3%, 8%]); and by race/ethnicity, Hispanics = 22% (95% CI [5%, 38%]), blacks = 5% (95% CI [-20%, 30%]), and whites = 7% (95% CI [5%, 10%]). Conclusions: Postreform use of major inpatient procedures increased more among nonelderly lower and medium area income populations, Hispanics, and whites, suggesting potential improvements in access to outpatient care for these vulnerable subpopulations.