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

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.