In 1976, the Cockcroft-Gault equation for creatinine clearance (CCr) was developed, simplifying the estimation of glomerular filtration rate (GFR) based on the level of serum creatinine (SCr) alone (Cockcroft, 1976).
CCr (mL/min) = (140 - Age) x Weight / (72 x [SCr])
- SCr: in mg/mL
- Age: in Years
- Weight: in kilograms (kg)
This equation is no longer recommended for routine use as:
- It is a calculation of CCr, not GFR - the same overestimating limitations apply (Clarke, 2016).
- It was developed using data from 249 men with creatinine clearance from approximately 30 to 130 mL/m2. It did not adjust for body surface area (National Kidney Foundation).
- It was not established using standardized creatinine assays, with subsequent loss of accuracy (Coresh, 2006).
