A new prognostic index for one-year survival in incident hemodialysis patients.
OBJECTIVE
Although scoring comorbidities for patients beginning chronic hemodialysis has proved significant and has led researchers to develop several indexes, none of them has been extensively accepted. The aim of this study was to: 1) develop a prognostic index for patients entering renal replacement therapy; and 2) identify which one of the available scores better predicts one-year survival.


METHODS
Records from 5,360 incident dialysis-requiring ESRD individuals were studied and a novel comorbidity index (NI) was developed. The agreement of this NI with the Charlson age-comorbidity, Kahn-Wright, ACPI, and Hemmelgarn indexes was assessed to identify which one better predicts one-year survival. The Cox proportional hazard regression with time-dependent covariates was used to analyze survival and the area under the receiver operating characteristic (ROC) curve was calculated to assess the ability of this score to discriminate between prognoses and to compare this NI with indexes already in use.


RESULTS
16 of the original 19 predictor variables displayed hazard ratios =1.2. Although the area under the ROC curves for all the indexes compared were significantly different from 0.5, the NI showed better performance characteristics (0.74 vs. 0.70 for Charlson's, 0.68 for ACPI, 0.67 for Khan-Wright's and 0.63 for Hemmelgarn's). Compared with the Charlson score, the z statistic was 7.78 (p<0.001). One-year survival estimate for the high-risk group was 43% with the NI and ranged from 66% to 72% when assessed through other indexes.


CONCLUSIONS
We recommend the use of this NI because it better predicts the one-year survival probability of incident hemodialysis-requiring ESRD individuals.
Committee on Epidemiology and Registration, Argentina Society of Nephrology, Buenos Aires, Argentina. smarinovich@fibertel.com.ar
Sergio
S
Marinovich
Carlos
C
Lavorato
Claudio
C
Moriñigo
Eduardo
E
Celia
Liliana
L
Bisignano
Mariano
M
Soratti
Daniela
D
Hansen-Krogh
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001118:Argentina; D015897:Comorbidity; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012372:ROC Curve; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome