Creatinine Clearance (Cockcroft-Gault)
Estimates creatinine clearance using the Cockcroft-Gault formula. Preferred for drug dosing decisions (especially DOACs) per MHRA guidance, as eGFR may overestimate renal function in certain populations.
years
Age in years.
kg
Actual body weight. At extremes of weight, consider ideal body weight or adjusted body weight per local guidance.
mg/dL
Serum creatinine in mg/dL. If umol/L, divide by 88.4.
Female multiplier = 0.85.
References
- Calculating kidney function - UK Specialist Pharmacy Service — NHS/SPS (2022)
- Comparison of Measured Creatinine Clearance and Calculated GFR in Single Kidney Patients — Journal of Nephrology/PMC (2011)
Note: MHRA recommends Cockcroft-Gault for DOAC dosing decisions. CrCl is not the same as GFR - it overestimates GFR by 10-20% due to tubular creatinine secretion. Consider calculating with ideal, adjusted, and actual body weight when near dose thresholds.
Warnings & Limitations
- Controversy exists over which weight to use at extremes of body weight.
- In morbid obesity, actual body weight may overestimate; consider adjusted body weight.
- In frail patients, actual body weight may underestimate renal function.
- Requires stable creatinine (not valid in acute kidney injury).