RESUMEN
Cockcroft and Gault's formula is frequently used to estimate creatinine (Ccr) in clinical practice. To determine the accuracy of such estimation in Korean patients, we measured simultaneously, serum creatinine and 24-hour urinary creatinine excretion in 696 Korean patients (male:350, female:346). Measured Ccr was significantly different from estimated Ccr in several age groups and the decrease of creatinine excretion with age is less than Cockcroft and Gault's estimation. We assumed that this difference can be due to difference of the body habitus and difference of urinary creatinine excretion per body weight between different races. So we divided the sample population into two groups and derived the new formula in one group with regression analysis between age and 24 hour urinary creatinine excretion per body weight for estimation of Ccr as Cockcroft and Gault derived their formula and applied it to another group to compare the new formula with Cockcroft and Gault's formula in Korean patients. The new formula was Ccr (mL/min)=[ (260-age)x weight (kg)]/[160 x serumCr (mg/dL)] for male and Ccr (mL/min)-[ (236-age) x weight (kg)]/[180 x serum Cr (mg/dL)] for female. Predictive accuracy of the new formula was significantly better than the Cockcroft and Gault's formula in the other sample population and also in subgroup of the patients with azotemia.