Association between GFR Estimated by Multiple Methods at Dialysis Commencement and Patient Survival

Abstract

SummaryBackground and objectives The Initiating Dialysis Early and Late study showed that planned early or late initiation of dialysis, based on the Cockcroft and Gault estimation of GFR, was associated with identical clinical outcomes. This study examined the association of all-cause mortality with estimated GFR at dialysis commencement, which was determined using multiple formulas.Design, setting, participants, & measurements Initiating Dialysis Early and Late trial participants were stratified into tertiles according to the estimated GFR measured by Cockcroft and Gault, Modification of Diet in Renal Disease, or Chronic Kidney Disease-Epidemiology Collaboration formula at dialysis commencement. Patient survival was determined using multivariable Cox proportional hazards model regression.Results Only Initiating Dialysis Early and Late trial participants who commenced on dialysis were included in this study (n=768). A total of 275 patients died during the study. After adjustment for age, sex, racial origin, body mass index, diabetes, and cardiovascular disease, no significant differences in survival were observed between estimated GFR tertiles determined by Cockcroft and Gault (lowest tertile adjusted hazard ratio, 1.11; 95% confidence interval, 0.82 to 1.49; middle tertile hazard ratio, 1.29; 95% confidence interval, 0.96 to 1.74; highest tertile reference), Modification of Diet in Renal Disease (lowest tertile hazard ratio, 0.88; 95% confidence interval, 0.63 to 1.24; middle tertile hazard ratio, 1.20; 95% confidence interval, 0.90 to 1.61; highest tertile reference), and Chronic Kidney Disease-Epidemiology Collaboration equations (lowest tertile hazard ratio, 0.93; 95% confidence interval, 0.67 to 1.27; middle tertile hazard ratio, 1.15; 95% confidence interval, 0.86 to 1.54; highest tertile reference).Conclusion Estimated GFR at dialysis commencement was not significantly associated with patient survival, regardless of the formula used. However, a clinically important association cannot be excluded, because observed confidence intervals were wide.

Dialysis initiation, modality choice, access, and prescription: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

“…Indeed, the IDEAL study did not demonstrate any clinical benefit in commencing dialysis at higher levels of eGFR, and the variability in measurement of eGFR in CKD G5 is such that it should not be considered to reliably reflect kidney function. 31 Registry data indicate mean predialysis eGFR varies among countries (approximately 5 ml/min per 1.73 m 2 in Taiwan; average 8.5 in the UK, 7.3 in Australia, 6.4 in New Zealand, 9-10 in Canada and France, and 11 in the US). [32][33][34][35] Generally, current guidelines do not support preemptive dialysis initiation, [36][37][38] although an exception is the 2011 European guideline.…”

The Impact of Timing of Dialysis Initiation on Mortality in Patients with Peritoneal Dialysis

“…Recently, a randomized controlled trial, the Initiating Dialysis Early and Late (IDEAL) study, demonstrated that a planned early dialysis initiation (eGFR 10 -14 mL/ min/1.73m 2 ) was not associated with improvement in survival or clinical outcomes compared with late dialysis initiation (eGFR 5 -7 mL/min/1.73m 2 ) (18,19).…”

Rate of Decline of Kidney Function, Modality Choice, and Survival in Elderly Patients with Advanced Kidney Disease

“…The premise underlying the use of eGFR as an indicator of kidney function in this setting can also be questioned. The method is based on measurements of serum creatinine, which in this setting may be as reflective of muscle mass as of kidney function [25,26], though this issue would relate similarly to those on the dialysis and CKM pathways. The difference in timing of the follow-up eGFR measurement may also be important, since the measurement in those on the CKM pathway was taken nearer to death.…”