Comparison of mortality and intermediate outcomes between medicare dialysis patients in HMO and fee for service.

End-stage renal disease (ESRD) is the only disease entitlement for Medicare; therefore, most patients with ESRD have Medicare coverage. Patients with ESRD are prohibited by law from enrolling in health maintenance organizations (HMOs), the only group prohibited within Medicare. However, they may remain in an HMO if they enrolled in such a plan before their kidneys failed. Thus, it is possible to compare patients with ESRD in HMOs with those in fee-for-service (FFS) plans. To determine whether mortality, transplantation rates, and intermediate outcomes differed between Medicare ESRD beneficiaries enrolled in HMO versus FFS providers, a retrospective cohort analysis was performed of patients with ESRD from three Health Care Financing Administration data sets containing administrative and outcome information for Medicare ESRD beneficiaries from 1990 to 1998. On December 31, 1998, a total of 278,510 prevalent patients with ESRD were in FFS plans, and 18,332 patients were in HMOs. HMO patients were older and more likely to be white and male and have diabetes mellitus and comorbid cardiovascular conditions than FFS patients. Unadjusted 2-year survival rates were 48.4% and 49.3% for FFS and HMO patients, respectively. In a multivariate model, HMO status had no significant effect on mortality, which was greater with older age, male sex, and white race. In 1998, unadjusted renal transplantation rates were 23.5% and 15.5% for FFS and HMO patients, respectively; age adjustment abrogated the apparent difference. For FFS and HMO patients, adequate hemodialysis was delivered to 72% and 82%, and 56% and 62% had hematocrits greater than the benchmark, respectively. There was no statistical difference in these outcomes in multivariate comparison. In conclusion, care by HMO for patients with an expensive chronic illness can achieve outcomes similar to those for FFS patients. Claims of poorer care and worse outcomes for patients with ESRD enrolled onto an HMO, an argument used to justify continued prohibition against widespread participation by patients with ESRD, are not supported.