Comparison of CKD-EPI, C-G and MDRD equations for estimating glomerular filtration rate in chronic kidney disease population in South-Western Nigeria

Background: Ethnic variabilities make reliability of formula equations for assessing glomerular filtration rate (GFR) doubtful in many  populations. We compared Cockroft-Gault (CG), modification of diet in renal disease (MDRD), and chronic kidney diseases epidemiology  collaboration (CKD-EPI) equations in adult Nigerian CKD subjects. Methodology: We measured 24-hour-urinary creatinine clearance of 311 adult CKD patients and compared with the three estimated  equations. Bland-Altman plots were used to assess agreement between estimated equations and measured creatinine clearance (mGFR).  Receiver-operating curve (ROC) analysis was used to assess the diagnostic power of the equations. Equation with accuracy within 30% of mGFR of ≥90% was considered acceptable for use. Results: Mean age was 41.9±12.7 years with 182(58.5%) females. The mean GFR using  CKD-EPI, 2 MDRD and CG equations were 69.5±33.9, 65.9±33.0 and 66.2±30.9 mls/min/1.73m respectively 2 (mGFR 68.3±31.1mls/min /1.73m ). The 3 equations showed positive correlation to mGFR (r=0.95) but CKD-EPI had the least bias. Conclusion: All three equations  can be used but CKD-EPI equation is preferable in Nigerian CKD patients, especially with GFR> 60mls/min.