Duke 2008 | ASHE | Equity and Efficiency in Health and Healthcare

Previous studies examining disparities in health care expenditure have assessed mean differences /disparities across racial and ethnic groups, often overlooking differences in the tails of the distributions of both the dependent and continuous predictor variables. When they have corrected for differences in patient characteristics, they have examined mean differences conditional on the distributions of characteristics across the groups With attention turning to caring for particularly vulnerable populations, it may be useful to policymakers to assess whether discrepancies are exacerbated or diminished at the high end of expenditures where individuals are likely to have more critical health issues.

The objectives of this study are to assess African-American-white and Hispanic-white disparities in total health care expenditure across the distribution of dependent and predictor variables. As one moves toward the outer quantiles of expenditure conditional on the covariates, do the differences by group increase or abate? Is there any point in the response that African Americans and Hispanics catch up with non-Hispanic whites as one gets into the right tail of the distribution? Based on the results, we will recommend methods for future disparities work, and inform policy by assessing disparities among individuals that receive the most medical resources. Data used are from the 2001 - 2004 Medical Expenditure Panel Surveys (MEPS), weighted to be nationally representative of the white, African-American, and Hispanic population in the United States. These data have more complete and reliable health status measures than other waves of the MEPS. Disparities are measured as differences between actual white expenditures and model predictions generated using the distribution of covariates for each minority group and coefficients from the non-Hispanic white group. Quantile regression was used to measure the differences in disparities at the 25th, median, 75th, 90th, and 95th quantiles. Tests for differences over the distribution of health care expenditures were conducted using simultaneous quantile regression with bootstrapped standard errors corrected for design effects. Overall model fit and the fit for major covariates was verified using the modified Hosmer ? Lemeshow test. Preliminary results find that African-American-white and Hispanic-white disparities diminish in upper quantiles of expenditure, but remain significantly below that of non-Hispanic whites throughout the distribution. The magnitude of these disparities is sensitive to adjustment of demographic, health status, and SES variables, but disparities persist qualitatively. In addition, the known differences in access (any use) persist after correction for patient characteristics. Numerous studies have documented African-American-white and Hispanic-white disparities in access to medical care. This study assesses the magnitude of these disparities across the distribution of health care expenditures. While disparities are reduced in higher quantiles compared to the median and lower quantiles, these high expenditure minority groups are still receiving significantly disparate care. Disparity reduction programs should consider the prioritization of improved access to quality care among minorities with critical health issues. The authors recommend that future research on medical expenditure disparities use methods that measure disparities throughout the distribution, especially if their concern is primarily about the sickest end of the spectrum.