Racial Disparities Widespread in Medicare Health Plans

BOSTON, Oct. 26 --The quality of care in Medicare managed- care plans is far from optimal for all enrollees, varies from plan to plan, and is unequal for black patients, researchers reported.

High-quality health plans had racial disparities in care that were generally similar to those of low-quality plans, according to a report in the Oct. 25 issue of the Journal of the American Medical Association. Only one plan achieved both high quality care and low racial disparity on more than one health-outcome health measure.

Furthermore, differences in racial outcomes were largely attributable to poor outcomes for black patients even within the same plan and not to enrollment of black patients into lower-performing plans, said a team including John Ayanian, M.D., of Harvard Medical School here, and Amal Trivedi, M.D., of Brown University in Providence, R.I.

Although other studies have assessed racial disparities in the Medicare program, this study is the first to examine disparities in a nationally representative sample, Drs. Ayanian and Trivedi said.

To assess plan variations in overall quality and racial disparity, the researchers used four outcome measures from the Health Plan Employer and Data Information Set (HEDIS). The study included results from a nationally representative sample of 431,573 individual observations from 151 Medicare health plans from 2002 to 2004. The plans were both private and non-profit, large and small, and covered 38 states.

In the study cohort, 12% of the observations were for black enrollees and 52% for female enrollees. Patients' mean age was 71. Blacks were more likely to be from newer plans, plans located in the South and Northeast, smaller plans, and for-profit plans.

Using multilevel multivariable regression models, the researchers measured outcomes for four significant health measures: glycosylated hemoglobin_c less than 9.5% or less than 9.0% for enrollees with diabetes; low-density lipoprotein cholesterol (LDL-C) less than 130 mg/dL for those with diabetes or after a coronary event; and blood pressure less than 140/90 mm Hg for patients with hypertension.

The health plans varied substantially both in overall quality and In racial disparity on each of the four outcome measures.

Overall, clinical performance on HEDIS outcome measures was lower for black enrollees than for white enrollees (P<.001 for all). The measures ranged from 6.8% lower for blood pressure control, to 8% lower for hemoglobin A_1c, and 9.3% and 14.4% lower for LDL-C control in diabetics and patients after a coronary event, respectively, the researchers reported.

For each measure, more than 70% of this disparity was due to different outcomes for black and white individuals enrolled in the same health plan rather than assignment of black enrollees to lower-performing plans, while a smaller proportion was due to a disproportionate enrollment of black individuals in lower-performing plans.

Medicare health plans varied widely in both their overall performance and the magnitude of racial disparity, Drs.Ayanian and Trivedi wrote. Nevertheless, the racial gap persisted even after controlling for age, education, income, and the location and size of the health plan, the researchers said.

For example, absolute differences between the top-ranked and bottom-ranked health plan on the four outcome measures ranged from 35% to 70%. Although some health plans did not exhibit significant disparities between white and black enrollees, other plans had absolute racial disparities exceeding 20% on these measures.

Moreover, the investigators noted that the proportion of black enrollees within a plan was not an independent predictor of clinical performance.

Despite substantial evidence that controlling blood pressure, glucose, and cholesterol can improve survival, 21% to 41% of enrollees did not achieve relatively liberal goals for these measures. The data clearly show that even high-performing plans do not provide effective care for all people.

As for black enrollees, clinical performance on the four outcome measures was even worse, with absolute rates that were 6.8% to 14.4% lower than those of their white counterparts.

A strength of the study, the researchers wrote, was its large and geographically diverse sample and the use of validated and audited quality measures.

Limitations included the lack of information on related measures, such as whether appropriate therapy was started or increased in patients with suboptimal control, and on prescription drug coverage.

The researchers also lacked information on physicians' practices within these Medicare plans, and finally they noted that they lacked data on Hispanic and other ethnic enrollees, for whom, they said, Medicare data on race and ethnicity are relatively inaccurate.

Summing up, the researchers suggested that for the Medicare program, plan-specific performance reports of the effect of racial disparities on outcome measures would provide useful information and a dimension of quality not currently assessed by the HEDIS reporting system.