Under HMOs, Medicaid patients fare worse than commercial HMO patients

Once viewed as a panacea to the nation's health care problems, HMOs have fallen out of favor.

Commercially insured patients who flooded into HMOs, or managed care, in the early 1990s left in droves by the end of the decade. Medicaid patients, however, don't always have the luxury of choosing their health plans, and the proportion of Medicaid beneficiaries enrolling in HMOs continues to increase.

A new study by researchers at Harvard Medical School and Harvard School of Public Health shows that under HMOs, Medicaid patients fare worse than commercial HMO patients on 10 of 11 quality measures. Though policy makers once hoped that HMOs would eliminate the quality of care gap between the Medicaid and commercial populations, this clearly hasn't happened.

“There was a lot of hope that managed care would eliminate disparities between the Medicaid population and the commercial population,” says Bruce Landon, an associate professor at Harvard Medical School and first author on the paper, which appears in the Journal of the American Medical Association on Oct. 10. “HMOs may have moved care in that direction, but there is still a gap in the care that Medicaid and commercial patients receive.”

Using data from 383 health plans, the researchers looked at four groups:

• Medicaid beneficiaries enrolled in HMOs that serve only the Medicaid population.
• Medicaid beneficiaries enrolled in HMOs that serve both the Medicaid population and the commercial population.
• Commercial patients enrolled in HMOs that serve both the Medicaid population and the commercial population.
• Commercial patients enrolled in HMOs that serve only the commercial population.

HMOs serving only the Medicaid population and HMOs serving both the Medicaid and the commercial populations appear to provide about the same quality of care to Medicaid patients. But the care falls short of that provided to commercial patients in HMOs. Even within the same health plan, commercial enrollees received higher quality of care on almost all of the measures examined.

“Across the 10 measures, we saw quality of care differences ranging from 5 to 25 percent, a difference that has substantial clinical implications for patients with chronic conditions such as diabetes,” says senior author Arnold Epstein, who is a professor at the Harvard School of Public Health. “Medicaid patients received better care than commercial patients in only one area—Chlamydia screening.”

The study did not include Medicaid patients who are not enrolled in managed care, so it is certainly possible that HMOs serve the Medicaid population better than traditional Medicaid. But HMOs do not eliminate the quality of care gap between Medicaid patients and the commercial population.

The researchers measured care in three main areas—prevention and screening, chronic disease management, and care for pregnant women—and discovered striking differences. For example, female Medicaid beneficiaries receive 25 percent less postpartum care than their commercial counterparts, and Medicaid patients with diabetes were 15 percent more likely to have unacceptable blood sugar levels than their commercial counterparts.

“Part of the gap might be explained by the patients themselves, for it's possible that the Medicaid population is less able to adhere to doctors' recommendations than the commercial population,” says Landon, who is also an associate professor of medicine at the Beth Israel Deaconess Medical Center. “But I suspect Medicaid patients may also fare worse because they visit doctors and hospitals of lower quality.”

“This study suggests that policy makers must develop new, novel strategies if we are going to eliminate the quality of care gap between the Medicaid and commercial populations,” adds Epstein, who is also a professor of medicine at Brigham and Women's Hospital.

This research was supported by a grant from the Robert Wood Johnson Foundation.