title: Comparison of creatinine clearance estimates with routine measured clearance in adult Jordanians with a kidney transplant.
abstract: OBJECTIVE
  There are conflicting data on using the Cockroft-Gault formula and the Modification of Diet in Renal Disease formula to assess graft function in kidney transplants. This study uses a cohort of Jordanian kidney transplant patients to assess performance of the Cockroft-Gault formula and the Modification of Diet in Renal Disease equations by using the criterion standard of measured creatinine clearance.
  
  
  METHODS
  Creatinine clearance measured by 24-hour urine creatinine in patients with a kidney transplant was compared with the estimated clearance using the Cockroft-Gault formula and the Modification of Diet in Renal Disease equations. Correlation, limits of agreement, and concordance analyses were used.
  
  
  RESULTS
  There was a positive correlation between both the Cockcroft-Gault (r=0.878; P < .001) and the Modification of Diet in Renal Disease (r=0.732; P < .001) equations with creatinine clearance. The former was statistically superior (P = .0416). Using Bland-Altman plots, the limits of agreement were wide for both methods. After log transformation, the limits of agreement were -0.06 to +0.27 for the Cockcroft-Gault formula, and -0.21 to + 0.26 for the Modification of Diet in Renal Disease. Concordance analyses showed a correlation coefficient of 0.7384 (95% CI: 0.6134 to 0.8273) when the Cockcroft-Gault formula was used, and 0.7257 (95% CI: 0.5622 to 0.8345) for the Modification of Diet in Renal Disease. Pearson P coefficient (precision) and bias correction factor Cb (accuracy) for the Cockcroft-Gault formula and for the Modification of Diet in Renal Disease were 0.8762, 0.8427, 0.7324, and 0.9908.
  
  
  CONCLUSIONS
  In Jordanian patients with a renal transplant, although the Cockcroft-Gault formula performed slightly better than the Modification of Diet in Renal Disease equation in estimating creatinine clearance, neither of these equations can accurately predict renal graft function.
authors.affiliation: Department of Internal Medicine, Division of Nephrology, University of Jordan, Amman, Jordan. aymiw@yahoo.com
authors.forename: Ayman M
authors.initials: AM
authors.lastname: Wahbeh
mesh_terms: D000328:Adult; D000367:Age Factors; D018912:Arabs; D015415:Biomarkers / Q000652:urine; D003404:Creatinine / Q000652:urine*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007597:Jordan / Q000453:epidemiology; D016030:Kidney Transplantation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011237:Predictive Value of Tests; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D003404:Creatinine