Estimated GFR Trajectories of People Entering CKD Stage 4 and Subsequent Kidney Disease Outcomes and Mortality

Abstract

Background: Estimated glomerular filtration rate (eGFR) trajectories of people entering chronic kidney disease (CKD) stage 4 and their associations with subsequent kidney disease outcomes or death are not known.

Study design: Longitudinal observational cohort study.

Setting & participants: 26,246 patients in the Veterans Affairs Healthcare System who entered CKD stage 4 in fiscal year 2008 followed up until October 2013.

Factors: 5-year eGFR trajectories, demographic and health characteristics.

Outcomes: Composite kidney disease outcome of kidney failure, dialysis therapy or transplantation, and death.

Results: Latent class group modeling and functional characterization suggest the presence of 3 distinct trajectory classes: class 1 (72%), consistent slow decline with absolute eGFR change of -2.45 (IQR, -3.89 to -1.16) mL/min/1.73m(2) per year; class 2 (18%), consistent fast decline and eGFR change of -8.60 (IQR, -11.29 to -6.66) mL/min/1.73m(2) per year; and class 3 (10%), early nondecline and late fast decline with eGFR change of -0.4mL/min/1.73m(2) per year in years 1 to 3 and -7.98 and -21.36mL/min/1.73m(2) per year in years 4 and 5, respectively. During 4.34 years of follow-up, 9,809 (37%) patients had the composite kidney disease outcome and 14,550 (55%) patients died. Compared to the referent group (trajectory class 1), HRs for 1-year risk for composite kidney disease outcome for trajectory classes 2 and 3 were 1.13 (95% CI, 1.05-1.22) and 0.67 (95% CI, 0.59-0.75), whereas HRs for 1-year risk for death for classes 2 and 3 were 1.17 (95% CI, 1.10-1.28) and 1.29 (95% CI, 1.18-1.42), respectively. The 1-year risk for composite kidney disease outcome was 32% and was 42% more likely than the risk for death in trajectory classes 1 and 2, respectively, whereas the risk for death was 67% more likely than the risk for composite kidney disease outcome in trajectory class 3.

Limitations: Inclusion criteria and mostly male participants limit generalizability of study results.

Conclusions: We characterized 3 different eGFR trajectory classes of people entering CKD stage 4. Our results suggest that the pattern of eGFR trajectory informs the risk for kidney disease outcomes and death.

Keywords: Chronic kidney disease (CKD); comorbid conditions; concordant; dialysis; discordant; disease progression; eGFR trajectories; end-stage renal disease (ESRD); estimated glomerular filtration rate (eGFR); kidney disease outcomes; kidney failure; kidney function trajectory; mortality; rate of kidney function decline; renal function trajectory; renal outcomes; stage 4 CKD; transplant; viral infections.