The appropriate use of serum creatinine level as a surrogate for time in th
e course of renal failure when dialysis commences requires it to be a signi
ficant predictor of mortality in incident patients with end-stage renal dis
ease (ESRD), This study evaluated factors that account for variations in cr
eatinine level before the initiation of dialysis and whether incident creat
inine level after controlling for these factors was a risk factor for morta
lity. This is a retrospective cohort study of patients from Maryland and Vi
rginia who initiated dialysis between April 1, 1995, and December 31, 1996,
with data ascertained from the Health Care Financing Administration Form 2
728, Multivariate models were used to evaluate both the factors that predic
t incident serum creatinine level and the association between creatinine le
vel and mortality. There were 5,388 patients followed up for an average of
23.6 +/- 0.2 months. Mean creatinine level was 9.2 +/- 0.1 mg/dL, with case
-mix factors most predictive of serum creatinine level and accounting for 9
% of its variance, Hematocrit and blood urea nitrogen levels as additional
surrogates far progression of renal disease accounted for 7.4% of the varia
nce, whereas the nutritional parameters, body mass index, and albumin level
only explained an additional 1% of the total variance in creatinine level.
Creatinine level was inversely correlated with mortality risk, and this re
lationship was sustained both with transformation into an estimated glomeru
lar filtration rate and multivariate adjustment for confounders (relative r
isk = 0.96; P < 0.0001), Creatinine values from an incident ESRD population
have a weak relationship with the timing of dialysis initiation but repres
ent a strong measure of health status. (C) 1999 by the National Kidney Foun
dation, Inc.