Women who are enrolled in Medicare HMOs and who are diagnosed with breast cancer are more likely to be diagnosed at an earlier stage than women covered by fee-for-service Medicare, according to research in the Journal of the American Medical Association. A National Cancer Institute/Health Care Financing Administration study of 22,000 women with breast cancer shows that 10.8 percent of fee-for-service beneficiaries were diagnosed at late stages, compared with 7.6 percent of HMO enrollees. Differences in early-stage detection rates were statistically insignificant.

The authors, who were careful to refrain from claiming that managed care is superior to fee-for-service medicine, noted that early-diagnosis rates varied widely among HMOs. However, researchers examined records of women who were diagnosed between 1988 and 1993 — a time when most plans did not yet adhere to National Committee for Quality Assurance standards that suggest regular screening mammograms for enrollees.