Prediction of creatinine clearance from plasma creatinine: comparison of five formulae.

1. Glomerular filtration rate is commonly assessed by measurement of endogenous creatinine clearance (CLcr). Several formulae have been described to calculate CLcr from plasma creatinine and we have evaluated the effectiveness of five formulae in 95 healthy subjects (17 F and 78 M, 20-25 years) and in 72 patients attending a renal clinic (48F and 24 M, 14-69 years). Endogenous CLcr was measured and the CLcr was also estimated by five formulae. 2. In healthy subjects CLcr calculated by the formulae of Cockcroft & Gault (1976) and Mawer et al. (1972) gave higher correlation coefficients than the other three formulae. 3. When all of the subjects with a wide range of CLcr (3.1-164) were considered all formulae gave good correlations, but the formula of Cockcroft & Gault (1976) gave the best estimate.