Retrospective and comparative assessment of MDRD, CKD-EPI, and EKFC equations for estimating glomerular filtration rate in a clinically heterogeneous hospital population

BACKGROUND: Chronic kidney disease (CKD) is projected to become the fifth leading cause of death by 2040. Accurate estimation of glomerular filtration rate (eGFR) is essential for diagnosis, staging, and management. Our laboratory still uses Modification of Diet in Renal Disease (MDRD) traceable to the Isotope Dilution Mass Spectrometry (IDMS) equation, which is now considered outdated due to reduced accuracy at higher eGFR values. More recent equations may offer improved performance. This study aimed to compare these four eGFR equations from both analytical and clinical perspectives to support the change of equation used in our laboratory. METHODS: Retrospectively, this study compared the routinely used MDRD equation with alternative eGFR formulas in order to evaluate the impact of adopting newer equations. RESULTS: . Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2009 had the strongest agreement and similar staging, while CKD-EPI 2021 generated higher eGFR values. European Kidney Function Consortium (EKFC) reclassified about 12% of patients into more advanced stages, possibly influencing clinical management. CONCLUSIONS: Both CKD-EPI 2009 and EKFC proved to be suitable alternatives to MDRD-IDMS. However, CKD-EPI 2009 was identified as the most potentially appropriate equation for implementation in our hospital setting due to the characteristics of the served population and its balanced impact on CKD stage reclassification.