Estimation of glomerular filtration rate from plasma creatinine concentration in children.

The relation between the true plasma creatinine concentration (Pc) and the glomerular filtration rate corrected for body surface area (GFR/SA) was investigated in 108 individuals, and the following formula was derived: GFR/SA (ml/min per 1-73m2SA) = 0-43 Ht (cm)/Pc (mg/100 ml). This formula was tested in a second group of 83 children, and its accuracy and precision was compared to the 24-hour creatinine clearance. It was found to be superior to the creatinine clearance overall, and was as good, even if all results involving suspect 24-hour-urine collections were eliminated from analysis. The formula in SI usage is: GFR/SA (ml/min per 1-73 m2SA) = 38 Ht (cm)1Pc (mumol/l).