Increases in market share of managed care--the percentage of people in an area enrolled in managed care plans--have been associated with decreases in resource use and expenditures for managed care enrollees. Expenditures in the fee-for-service health care sector have also been observed to decrease with increased managed care market share in what is often referred to as the spillover effect. However, whether this decrease in expenditures is also associated with changes in the quality of care received by patients, including cancer patients, is not known.

To examine associations between managed care market share and changes in the quality of care delivered to cancer patients in the fee-for-service sector, Nancy L. Keating, M.D., M.P.H., of Harvard Medical School in Boston, and colleagues studied a sample of Medicare beneficiaries who had been diagnosed with breast or colorectal cancer between 1993 and 1999.

The authors found that increases in the market share of managed care in a county were not associated with several indicators of quality of care in that county, including receipt of surveillance mammography after cancer diagnosis, receipt of radiation after breast-conserving surgery, receipt of adjuvant chemotherapy for stage III colorectal cancer, or surveillance colonoscopy after treatment for colorectal cancer. However, market share increases were associated with increased rates of one quality-of-care measure, surveillance of colorectal cancer patients with carcinoembryonic antigen, a blood test recommended for certain patients with colorectal cancer. Overall, they concluded that increases in the managed care market share had limited or no effect on the quality of care cancer patients received.
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Contact: Sarah L. Zielinski
jncimedia@oupjournals.org
301-841-1287
Journal of the National Cancer Institute
15-Feb-2005