HMO-enrolled Medicare patients who suffered a heart attack in California fared no worse—perhaps even a little better—than those who were covered by fee-for-service, according to a new UCSF study.
“The important finding was not the difference between HMOs and fee-for-service plans,” said author Harold Luft, PhD. “Rather, some HMOs were significantly better than others, as well as fee-for-service.” Luft is director of the UCSF Institute for Health Policy Studies.
The factor that appeared to make a difference was how patient referrals were handled. Some HMOs and most fee-for-service providers performed a coronary artery bypass graft (CABG) in the facility to which the patient was initially taken. But research on surgical outcomes has continually shown that high-volume surgical practices perform better, and this also applies to CABG procedures, according to Luft. The UCSF research found that HMOs in the study whose patients were treated only in higher-volume medical practices had more favorable outcomes.
Titled “Variations in Patterns of Care and Outcomes after Acute Myocardial Infarction,” the study is published in the August issue of Health Services Research.
“The best-performing HMOs were consistently referring their patients to high volume centers,” Luft said. “Future investigations should look at specific practice guidelines, quality review and other features and not simply pit fee-for-service against HMO.”
In this study, Luft assessed risk-adjusted results for HMOs and fee-for-service plans using hospital discharge and death certificate data. Luft linked that data set with Medicare enrollment files for those patients 65 and older discharged from California hospitals between 1994 and 1996.
Heart disease is the leading cause of death in the United States, killing more than 500,000 people each year. Cardiovascular disease cost the nation more than $200 billion in health care expenditures and lost productivity in 1992, according to Luft.
CABG surgery is an open-heart operation in which an artery or a piece of vein taken from the leg is attached to the blood vessel to detour blood around the blockage. CABG is the most common major heart surgery in the Western world.
Although a study of HMOs in Massachusetts yielded quite different findings, Luft “was not surprised” because there are substantial differences in the ways HMOs operate.
Because this study was performed with unidentified data, Luft could not say which HMOs performed best, although he would like to continue the study with identified data.