Search tips
Search criteria 


Logo of hsresearchLink to Publisher's site
Health Serv Res. 1999 April; 34(1 Pt 2): 365–375.
PMCID: PMC1089007

How much better can we predict dialysis patient survival using clinical data?


OBJECTIVE: To use three approaches to compare dialysis survival prediction based on variables included in the Standardized Mortality Ratio (SMR) with prediction based on a clinically enriched set of variables. DATA SOURCE: The United States Renal Data System Case Mix Severity data set containing demographic, clinical, functional, nutritional, and treatment details about a random sample of 4,797 adult dialysis patients from 291 treatment units, incident to dialysis in 1986 and 1987. STUDY DESIGN: This observational study uses baseline patient characteristics in two proportional hazards survival models: the BASE model incorporates age, race, sex, and cause of end-stage renal disease (ESRD); the FULL model includes these and additional clinical information. We compare each model's performance using (1) the c-index, (2) observed median survival in strata of predicted risk, and (3) predicted survival for patients with different characteristics. PRINCIPAL FINDINGS: The FULL model's c-index (0.709, 0.708-0.711) is significantly higher than that of the BASE model (0.675, 0.675-0.676), indicating better discrimination. Second, the sickest patients identified by the FULL model were in fact sicker than those identified as sickest by the BASE model, with observed median survival of 451 days versus 524. Third, survival predictions for sickest patients using the FULL model are one-third shorter than those based on the BASE model. CONCLUSIONS: The model with more detailed clinical information predicted survival better than the BASE model. Clinical characteristics enable more accurate predictions, particularly for the sickest patients. Thus, clinical characteristics should be considered when making quality assessments for dialysis patients.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.0M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Collins AJ, Hanson G, Umen A, Kjellstrand C, Keshaviah P. Changing risk factor demographics in end-stage renal disease patients entering hemodialysis and the impact on long-term mortality. Am J Kidney Dis. 1990 May;15(5):422–432. [PubMed]
  • Fisher ES, Whaley FS, Krushat WM, Malenka DJ, Fleming C, Baron JA, Hsia DC. The accuracy of Medicare's hospital claims data: progress has been made, but problems remain. Am J Public Health. 1992 Feb;82(2):243–248. [PubMed]
  • Held PJ, Port FK, Turenne MN, Gaylin DS, Hamburger RJ, Wolfe RA. Continuous ambulatory peritoneal dialysis and hemodialysis: comparison of patient mortality with adjustment for comorbid conditions. Kidney Int. 1994 Apr;45(4):1163–1169. [PubMed]
  • McClellan WM, Flanders WD, Gutman RA. Variable mortality rates among dialysis treatment centers. Ann Intern Med. 1992 Aug 15;117(4):332–336. [PubMed]
  • McClellan W, Soucie JM. Facility mortality rates for new end-stage renal disease patients: implications for quality improvement. Am J Kidney Dis. 1994 Aug;24(2):280–289. [PubMed]
  • Rettig RA, Sadler JH, Meyer KB, Wasson JH, Parkerson GR, Jr, Kantz B, Hays RD, Patrick DL. Assessing health and quality of life outcomes in dialysis: a report on an Institute of Medicine workshop. Am J Kidney Dis. 1997 Jul;30(1):140–155. [PubMed]
  • Shapiro MF, Park RE, Keesey J, Brook RH. The effect of alternative case-mix adjustments on mortality differences between municipal and voluntary hospitals in New York City. Health Serv Res. 1994 Apr;29(1):95–112. [PMC free article] [PubMed]
  • Wolfe RA. The standardized mortality ratio revisited: improvements, innovations, and limitations. Am J Kidney Dis. 1994 Aug;24(2):290–297. [PubMed]

Articles from Health Services Research are provided here courtesy of Health Research & Educational Trust