HMOs Offer Research Opportunities to Epidemiologists

NEW ORLEANS--Integrated health care systems, such as HMOs, offer clearadvantages for epidemiologic research, Edward Wagner, MD, MPH, said atthe American Society of Preventive Oncology (ASPO) annual meeting. Dr.Wagner is director of the Center for Health Studies of Group Health Cooperative,a Seattle-based HMO.

HMOs have a defined population of enrollees, he said, so that interventionstudies can be done without the use of volunteers, who are more likelyto show a good outcome and skew the results.

Two Group Health intervention studies, one with volunteer smokers andone with nonvolunteer smokers, showed that smokers who volunteered forthe study were much more likely to quit smoking than nonvolunteer smokers.Said Dr. Wagner: "There is much to be learned about differences involunteers and nonvolunteers in research programs."

HMOs also offer a defined population of providers. The gatekeeper systemimproves disease prevention, he said, because intervention is done by anaccountable provider. Computerized data can be linked to outcomes measurements,and specific providers can be evaluated by comparing their outcomes withevidence-based practice-based guidelines.

Dr. Wagner illustrated the advantages of defined populations of patientsand accountable providers by citing a low back pain study showing thatphysicians providing less pain medication and encouraging return to activityhad better results than physicians who treated low back pain with moremedication and bed rest.

Complete Health Data Bases

HMOs maintain increasingly complete health and health care utilizationdata on their enrollees, he said. Because HMOs offer comprehensive services,these computerized data bases contain information about the full rangeof health care received by each patient. "This facilitates studiesrelying exclusively or heavily on administrative data bases, which aremuch less bothersome to patients and less expensive," he said.

The availability of computerized pharmacy data at Group Health facilitatedthe development of a case mix measure--the chronic disease score. "Useof this measure allows researchers to adjust for the severity of illness,an important advantage in epidemiologic studies," Dr. Wagner said.

In addition, HMO computerized data bases can be linked with other importantdata bases, such as death and disease or regional cancer registries, toprovide further epidemiologic information on each enrollee.

"The research and prevention opportunities of HMOs depend on havinga large, representative population that is stable, receives all servicesfrom the plan, has accountable primary care providers, and makes data accessible,"he said. "We exploit this at Group Health."

A Different Philosophy

Managed care, with its emerging focus on outcomes measurements, offersopportunities to provide care that is most beneficial to most of the population,said another speaker at the ASPO meeting, Robert M. Kaplan, PhD, of theDepartment of Family and Preventive Medicine, University of California,San Diego.

This philosophy differs from that of the traditional biomedical model,he said. The traditional model emphasizes the diagnosis and treatment ofdisease, while the outcomes model focuses on extension of life and qualityof life. "Appropriate diagnosis and treatment should extend life expectancyand improve quality of life," he said, "but quality of life outcomesare rarely measured and are sometimes neglected in treatment decisions."

Dr. Kaplan said that there are some circumstances in which aggressivescreening may lead to treatment decisions that reduce quality of life withno clear evidence that life expectancy is improved. For example, the traditionalmodel for prostate cancer favors screening older men, while the outcomesmodel favors informing men of the complexities and involving them in decisionmaking.

Properly run managed care is the right setting for pursuing the outcomesmodel, since it seeks to maximize benefit to an entire population, Dr.Kaplan said. He added, however, that this model also emphasizes patientdecision-making and quality of life.