Disenrollment from Medicare managed care among beneficiaries with and without a cancer diagnosis

Abstract

Background: Medicare managed care may offer enrollees lower out-of-pocket costs and provide benefits that are not available in the traditional fee-for-service Medicare program. However, managed care plans may also restrict provider choice in an effort to control costs. We compared rates of voluntary disenrollment from Medicare managed care to traditional fee-for-service Medicare among Medicare managed care enrollees with and without a cancer diagnosis.

Methods: We identified Medicare managed care enrollees aged 65 years or older who were diagnosed with a first primary breast (n = 28 331), colorectal (n = 26 494), prostate (n = 29 046), or lung (n = 31 243) cancer from January 1, 1995, through December 31, 2002, in Surveillance, Epidemiology, and End Results (SEER) cancer registry records linked with Medicare enrollment files. Cancer patients were pair-matched to cancer-free enrollees by age, sex, race, and geographic location. We estimated rates of voluntary disenrollment to fee-for-service Medicare in the 2 years after each cancer patient's diagnosis, adjusted for plan characteristics and Medicare managed care penetration, by use of Cox proportional hazards regression.

Results: In the 2 years after diagnosis, cancer patients were less likely to disenroll from Medicare managed care than their matched cancer-free peers (for breast cancer, adjusted hazard ratio [HR] for disenrollment = 0.78, 95% confidence interval [CI] = 0.74 to 0.82; for colorectal cancer, HR = 0.84, 95% CI = 0.80 to 0.88; for prostate cancer, HR = 0.86, 95% CI = 0.82 to 0.90; and for lung cancer, HR = 0.81, 95% CI = 0.76 to 0.86). Results were consistent across strata of age, sex, race, SEER registry, and cancer stage.

Conclusion: A new cancer diagnosis between 1995 and 2002 did not precipitate voluntary disenrollment from Medicare managed care to traditional fee-for-service Medicare.

Figure 1

Kaplan–Meier analysis of voluntary disenrollment to fee-for-service Medicare among Medicare managed care enrollees with and without cancer. A) Breast cancer. B) Colorectal cancer. C) Prostate cancer. D) Lung cancer. The percent of beneficiaries with cancer (solid lines) and without cancer (dashed lines) who remained continuously enrolled in Medicare managed care after a cancer diagnosis (or matched beneficiary's cancer diagnosis) is shown. In each analysis, a log-rank test of time to voluntary disenrollment indicated that unadjusted differences between enrollees with and without cancer were statistically significant (P < .001). Enrollees with and without cancer were pair matched on age, sex, race, and geographic area. Observations were censored when one of the following events occurred: death; admission to hospice; or withdrawal, termination, or nonrenewal of the enrollee's managed care plan.

Figure 2

Kaplan–Meier analysis of voluntary disenrollment to fee-for-service Medicare in Medicare managed care enrollees with colorectal cancer, stratified by stage at diagnosis. A log-rank test of time to voluntary disenrollment indicated that unadjusted differences by stage at diagnosis were not statistically significant (P = .16). Observations were censored when one of the following events occurred: death; admission to hospice; or withdrawal, termination, or nonrenewal of the enrollee's managed care plan.