Abstract 136: Impact of Massachusetts Health Reform on Racial and Ethnic Disparities in Use of Inpatient Cardiovascular Surgeries
Authors: Hanchate Amresh D , Zheng Xin , Lasser Karen E , McCormick Danny , D'Amore Meredith , Kapoor Alok , Kressin Nancy R. 
Published: March 2022

BACKGROUND
The 2006 Massachusetts (MA) health reform increased insurance coverage to near-universal levels, but its impact on access to care or disparities in access is unclear. We examined post-reform change in racial/ethnic differences in use of two cardiovascular (CV) procedures, percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG), for which disparities in use have been noted in numerous past studies. As use of these procedures is sensitive to outpatient referral, impact of reform on procedure use can serve as a marker for impact on access to care. We hypothesized that reform will result in increased use of procedures, and that the increase in use will be greater among minorities. We contrasted the results with those for two comparable orthopedic procedures (total knee replacement [TKR] and total hip replacement [THR]).

METHODS
Using the comprehensive MA Hospital Inpatient Data of all discharges in all non-Federal hospitals from 1/1/2004 to 9/30/2009, we obtained state-level counts of individual procedures stratified into 30 cohorts by age (40-44, 45-49, 50-54, 55-59 & 60-64), sex and race/ethnicity (Whites, Blacks and Hispanics) for each quarter. To separate the impact of MA reform from secular changes, we used corresponding data from New York (SPARCS Inpatient Data) to capture changes unrelated to MA reform. To convert procedure counts into rates (# procedures/10,000 population), we obtained Census data to create a measure of population at risk for each cohort. Treating a quarter as the unit of time, the study period comprised of 10 pre-reform, 6 transition and 7 post-reform quarters. Applying a difference-in-difference specification, we used segmented time series Poisson regression models to estimate the impact of MA reform on the procedure rates for Blacks and Hispanics relative to those for Whites.

RESULTS
There was a secular decrease in MA in the use of PTCA and CABG (-8.0% per year for each) throughout the study period. In MA, compared to Whites, pre-reform rates of both procedures were lower among Blacks (Incidence Rate Ratio [IRR]: PTCA=0.79 & CABG=0.73; all p values < 0.001) but similar among Hispanics. For the post-reform period, the procedure rate in MA was unchanged for PTCA but was 11% higher (95%CI=[2%, 20%]) for CABG. MA reform was associated with 11% higher post-reform rates of PTCA+CABG (combined) use among Hispanics, albeit with marginal significance (95% CI=[-1%, 25%]), than that among Whites; no significant impact was noted for Blacks (2%; 95% CI=[-10%, 16%]). Orthopedic procedures experienced secular increases in use. Reform was associated with increased use of both procedures among Blacks (16%, 95% CI=[3%, 31%]) and Hispanics (42%, 95% CI=[20%, 69%]) than that among Whites.

CONCLUSIONS
MA health reform may have increased the use of CV and orthopedic procedures among minorities. While orthopedic procedure use increased among both Blacks and Hispanics, the increase for CV procedures was smaller in magnitude and limited to Hispanics. Impact of reform on use may vary with procedure type due to differences in pent-up demand and acuity of conditions treated.