Estimating glomerular filtration rate: comparison of chronic kidney disease epidemiology collaboration (CKD-EPI) and modification of diet in renal disease (MDRD) equations with the effect of age in a tertiary Hospital in Terengganu Malaysia

The CKD-EPI equation was developed to address the underestimation of the estimated glomerular filtration rate (GFR) by the Modification of Diet in Renal Disease (MDRD) equation at a level >60 mL/min/1.73m². The inclusion of diverse population in the development of the CKD-EPI equation has led to better eGFR estimation hence Ministry of Health Malaysia recommends the use of the CKD-EPI equation in their Clinical Practice Guideline 2018. The objective of this study is to evaluate the performance of CKD-EPI equation in our population focusing on the effect of age and inter-rater agreement between both equations particularly in elderly. Serum creatinine results was extracted from the lab information system (LIS) for a 1-year duration in a patient more and equal to 18 years old (≥18 years old). The first available creatinine result from 69,329 people were used to estimate GFR using both equations. The mean eGFR, prevalence of CKD and agreement between those two equations were compared. In comparison with MDRD equation, CKD- EPI equation revealed lower mean eGFR (82.63 vs 85.42 mL/min/1.73m², p<0.001) and reduced prevalence of chronic kidney disease (CKD) (25.7% vs. 28.4%). When subdivided by age, the prevalence of CKD reduced in age group 18-79 years but increased in elderly age >80 years. Numerical agreement of eGFR was excellent (ICC = 0.883) and categorical agreement of CKD was almost perfect in all age groups (ƙ= 0.932). CKD-EPI is an appropriate alternative for the MDRD equation in all ages including in the elderly. However further validation studies involving a large multiethnic and adequate elderly population in Malaysia are much needed.