Voluntary disenrollment from Medicare managed care: market factors and disabled beneficiaries.

Disenrollment rates from Medicare managed care plans have been reported to the public as an indicator of health plan quality. Previous studies have shown that voluntary disenrollment rates differ among vulnerable subgroups, and that these rates can reflect patient care experiences. We hypothesized that disabled beneficiaries may be affected differently than other beneficiaries by competitive market factors, due to higher expected expenditures...