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.

Value of corrected QT interval dispersion in identifying patients initiating dialysis at increased risk of total and cardiovascular mortality.

Cardiovascular disease remains the most common cause of premature death in end-stage renal disease (ESRD). Although several predictors of cardiac death have been reported, identifying individuals most at risk remains difficult. Previous studies in nonuremic populations have associated cardiac mortality, in particular sudden death, with increased QT dispersion (QTd); defined as the difference between the maximal and minimal QT interval on a standard electrocardiogram. The present study aimed to determine the prognostic value of QTd and corrected QTd (QTdc) in predicting total, cardiovascular, and arrhythmia-related mortality in ESRD patients initiating dialysis. The study was a retrospective cohort of adult ESRD patients starting peritoneal dialysis or hemodialysis between 1990 and 1994. Statistical analysis was by Cox proportional hazard modeling and Kaplan-Meier analysis. Primary study endpoints were total, cardiovascular, and arrhythmia-related mortality. Nonfatal cardiovascular events were a secondary endpoint. A total of 147 patients were studied for a period of 5 to 9 years. In Cox modeling, QTdc was an independent predictor of total (relative risk [RR] = 1.53; difference for RR = 50 msec; P = 0.0001) and cardiovascular mortality (RR = 1.57; difference for RR = 50 msec; P = 0.028) and trended toward arrhythmia-related mortality (P = 0.061). Total mortality also was predicted independently by lack of renal transplantation, radiographic cardiomegaly, and predialysis serum albumin. In multivariate analysis, QTdc was associated weakly with serum calcium, mean QT interval, and presence of diabetes mellitus. QTdc may be a useful marker for identifying dialysis patients at an increased risk for overall and cardiovascular mortality.

Analysis of the association of dialyzer reuse practices and patient outcomes.

This historic prospective study assessed the relationship between dialyzer reuse practices and hemodialysis patient mortality through 1 year of follow-up. Medicare patient demographic and survival data were combined with dialyzer reuse data from the Centers for Disease Control and Prevention's annual survey of dialysis-related diseases. Data were analyzed for the US Medicare hemodialysis population of never transplanted patients prevalent on January 1, 1989, and January 1, 1990, who were treated in freestanding dialysis units that used primarily conventional (not high-flux) dialyzers. Time to mortality, or transplant, and other censoring on December 31st of each year was regressed with proportional hazards models on patient, dialysis unit, and reuse measures. Age-, race-, and diagnosis-standardized mortality ratios for dialysis units were also regressed with weighted least squares techniques against dialysis unit and reuse measures. The results showed that patients treated in dialysis units that disinfected dialyzers with a peracetic acid, hydrogen peroxide, acetic acid mixture, or glutaraldehyde experienced higher mortality than patients treated in units that used formalin or in units that did not reuse dialyzers. The relative risk of mortality, compared with patients treated in nonreuse dialysis units, was 1.17 (P = 0.010) for glutaraldehyde and 1.13 (P < 0.001) for the peracetic acid mixture. The relative risk for formalin compared with the reference group of nonreuse was 1.06 (P = 0.088). With adjustment for several patient and dialysis unit characteristics, dialyzer reuse with certain germicides was associated with a significantly elevated mortality risk. This elevated risk, the etiology of which is currently not known, may represent a large number of potentially avoidable deaths per year. Only a large, nationally based analysis of this type has sufficient sample size to detect mortality risks such as these.