Clinical studies
A simple comorbidity scale predicts clinical outcomes and costs in dialysis patients

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Abstract

PURPOSE: In a university-based dialysis program, we found that 25% of the patients accounted for 50% of the costs and 42% of the deaths. We determined whether the Charlson Comorbidity Index, a simple measure of comorbid conditions, could predict clinical outcomes and costs in these patients.

METHODS: Patients on hemodialysis or peritoneal dialysis from July 1996 to June 1998 at the University of Pittsburgh outpatient dialysis unit were studied. Comorbidity scores and outcomes were determined by reviewing the Medical Archival Retrieval System database and outpatient records.

RESULTS: Two hundred sixty-eight patients were observed for 293 patient-years. The Comorbidity Index strongly predicted admission rate (relative risk per each unit increase = 1.20; 95% confidence interval [CI]: 1.16 to 1.23, P = 0.0001), hospital days and inpatient costs (both P <0.0001), and mortality (relative risk per unit increase = 1.24, 95% CI: 1.11 to 1.39, P = 0.0002.). Age and diabetes, used in the Health Care Financing Administration dialysis capitation model, correlated poorly with outcomes.

CONCLUSIONS: The modified Charlson Comorbidity Index predicts outcomes and costs in dialysis patients. This index may be useful in determining appropriate payment for care of dialysis patients under capitated payment schemes and as a research tool to stratify dialysis patients in order to compare the outcomes of various interventions.

Section snippets

Patients and methods

The study sample included all patients on hemodialysis or peritoneal dialysis at the University of Pittsburgh outpatient dialysis unit from July 1, 1996, to June 30, 1998. Home hemodialysis patients, patients transferred from another country, and patients for whom information could not be obtained were excluded. Patients were observed until the end of the study period, death, transplant, or transfer out of the unit.

Demographic data and information on comorbid conditions were obtained from the

Results

Of the 291 dialysis patients in our unit, 268 patients were studied for a total of 293 patient years (mean [± SD] of 1.1 ± 0.7 years per patient). Two patients transferred their care from another country, information could not be obtained on 6 patients, and 15 patients receiving home hemodialysis were excluded.

The patients’ mean age was 53 ± 16 years (Table 2). Diabetes was the leading cause of end-stage renal disease. Compared with national data from the United States Renal Data System, the

Discussion

The Health Care Financing Administration is exploring the use of capitated payment schemes, rather than the current fee-for-service plans, to control the costs of caring for patients with end-stage renal disease 3, 14. A capitated approach is attractive because a small number of patients account for these costs, and a small number of physicians, usually nephrologists, control nearly all aspects of their care (8). Despite these advantages, there is little experience in capitating the care of

Acknowledgements

We thank Mr. Jeff Rohay of Network 4 for statistical analysis. We acknowledge the critical review and suggestions by Dr. Beth Piraino, Dr. Linda Fried, and Ms. Judith Bernadini.

References (23)

  • V.E Pollack et al.

    Continuous quality improvement in chronic diseasea computerized medical record enables description of severity index to evaluate outcomes in ESRD

    Am J Kidney Dis

    (1992)
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    Supported by a grant from Dialysis Clinic, Inc. Nashville, Tennessee. Srinivasan Beddhu was recipient of a grant from the Emma Samuel Winters Foundation.

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