Predictive performance of the estimating equations of renal function in Sri Lankan subjects

Abstract

Objectives: This study validates two popular predictive equations of renal function firstly, Modifications of Diet in Renal Disease and secondly, Chronic Kidney Disease Epidemiology Collaboration equations for Sri Lankan cohort. We used data of the patients referred to Renal Research lab of University of Colombo for creatinine clearance measurement. Results: Predictive performances varied with the gender. Creatinine clearance and predicted renal functions were compared. Both fared unsatisfactorily with R2 ranging from 0.632 to 0.652, and overestimated renal function by 6-15%. The proportion chronic kidney disease staging 1 and 2 returned by Chronic Kidney Disease Epidemiology Collaboration equation showed significant difference, in females. Modifications of Diet in Renal Disease equation significantly under-estimated advanced chronic kidney disease in females. Chronic Kidney Disease Epidemiology Collaboration equation had better accuracy. The study sample had more females, Asian and lower body size and better renal functions than historic cohorts. Thai and Pakistani studies show both equations and their Asian adaptations fare poorly. Chronic kidney disease stages differ significantly with the equation used. Predictive equations have fared unsatisfactorily by overestimating renal functions. We recommend further studies using gold standards of measuring renal function.