[Formula creatinine clearance as a substitute for 24-hour creatine clearance in children with kidney transplantation].

Despite many theoretical advantages, formula-creatininclearance (Schwartz et al, Journal of Pediatrics 1976) has not found broad clinical acceptance in everyday pediatric patient care. In this study we report our results of long term observations (11.7 +/- 6.8 (1.7-24.8) months) of measured and computed creatininclearance in 27 children after renal transplantation (15 boys, 12 girls, mean age 14.5 +/- 4.2 (5.5-20) years) at the Kinderdialyse of the Universitäts-Kinderklinik of Vienna. We found a wide scattered correlation between the measured and computed creatininclearance values with a 90% confidence interval between -30% to +60% of the 24 hour creatininclearance. Formula creatininclearance (SD 17.8%) was markedly better reproducable than the 24 hour creatininclearancethe (SD 37.8%), the intraindividuell collecting error (36.1%) was almost twice the interindividuell "coefficient" error (20.27%). We therefore conclude that the 24 hour creatininclearance is by far not as accurate as the complexity of the procedure pretends and support broad clinical acceptance for the formula creatininclearance.