Study findings favor non-profit HMO care

Investor-owned health maintenance organizations fall short of non-profit HMOs in 14 quality-of-care indicators, according to a recent study published in the Journal of the American Medical Association (vol. 281, no. 2).

The study, co-authored by David U. Himmelstein, Steffie Woolhandler, Ida Hellander and Sidney M. Wolfe, compared the 1996 Health Plan Employer Data and Information Set quality-of-care data for 329 HMO plans (248 investor-owned and 81 non-profit), representing 56% of total HMO enrollment in the United States. HEDIS is a standardized set of quality measures set up by the National Committee of Quality Assurance to accredit HMOs.

"The differences we observed in this study appear to be clinically significant," according to the authors. "For instance, if all 23.3 million American women between ages 50 and 69 years were enrolled in investor-owned rather than non-profit plans, an estimated 5,925 additional breast cancer deaths would be expected (based on our finding of a 4.8% difference in screening rates and previous estimates that biennial screening in this age group would result in 52 fewer breast cancer deaths by age 80 years per 10,000 women screened)."

But those who disagree with the conclusions drawn from the study claim that the differences in the quality-of-care percentages have little to do with actual profit motive.

According to Mark Callahan, director of outcomes research for the New York Presbyterian Health Care System, the conclusions drawn from the study reflect differences among HMO models - not their tax statuses.

"The problem I see with the study is that most of the non-profit HMOs use what are called staff, or group, models," Callahan said. "Staff, or group, models mean you have groups of physicians who are joined to the hip [and] who are joined at the hip to the HMO. Most of the for-profit HMOs use network or independent practice association models where doctors in private practice contract with multiple HMOs to take care of their patients."

According to Callahan, the staff or group models used by non-profit HMOs have integrated information systems that allow them to track patients better. "I think what this study is measuring is that group and staff models do a better job of delivering these kinds of care than do IPA and network models," he said.

The American Association of Health Plans, a national trade organization representing HMOs, Preferred Provider Organizations and other similar health plans, had a similar reaction.

"The study...seeks to attribute [performance] to differences in the tax status of the various managed care plans," said the organization in a statement. "We believe the study understates other differences, especially those attributable to data collection in the various model types." PR