Evaluation and applicability of predictive equations of the glomerular filtration rate in chronic kidney disease

Prediction equations of glomerular filtration rate (GFR) may facilitate early detec-tion, evaluation and management of chronic kidney disease (CKD). However, the reliability of these equations was not extensively studied in our CKD population. Hence, the present study was aimed to determine the performance of modification of diet in renal disease (MDRD) and Cock-croft Gault formulas in predicting GFR in CKD patients and their relationship with the measured GFR. A total of 104 subjects (71 male and 33 female, aged 26-68 years) with different stages of CKD were recruited for this study; we excluded 51 patients due to improper collection of 24-h urine. The GFR was measured using 24-h creatinine clearance and predicted by the Cockcroft Gault, the 4-variable MDRD and the 6-variable MDRD equations. Prediction equations corre-lated well with the measured GFR. However, the predicted GFR using the 4-variable MDRD equation revealed a highly significant positive correlation with the GFR measured by creatinine clearance (r = 0.86, P < 0.001), followed by the 6-variable MDRD and Cockcroft-Gault equations with r = 0.85 and 0.77, P < 0.001, respectively. In conclusion, the present study predicts that the 4-variable MDRD is the best available equation for predicting GFR in our CKD population.