Creatinine Clearance (Cockcroft-Gault) Without BMI Adjustment
Calculates CrCl using the Cockcroft-Gault Equation
Jennifer Glen
Provided by
EVAL FoundationMin 0 – Max 200
Min 0 – Max 500
Min 0 – Max 50
Usage
Cockcroft-Gault (CG) equation was the the first (1976) equation to estimate kidney function using non-standardized creatinine measurements for determining creatinine clearance, which estimates glomerular filtration rate (GFR). Primary uses include chronic kidney disease staging, and discontinuing or adjusting medication dosage. While creatinine clearance may over-estimate GFR by 10-20%, creatinine clearance is the standard for drug dosing adjustments.
The CG equation has fallen out of favor with the advent of newer creatinine assays using internationally standardized creatinine measurements which has a tendency to bias the CG equation toward overestimation of GFR (10-40%). Additionally, variations in body composition among patients can also contribute to inaccuracies at weight extremes (Brown, 2013 & Winter, 2012). Based on expert opinion, additional adjustments to the CG equation are included based on body weight and BMI. Despite these limitations, the CG equation remains relevant as may drug dosing recommendation for patients with decreased kidney function were based on creatinine clearance calculations from the CG equation.
Note: The estimated GFR measured in the MDRD and the CKD-EPI equations demonstrate better concordance with measured GFR that does the CG equation. These equations are also appropriate for determining drug dosing.
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Summary
The Cockcroft-Gault (CG) Equation is one of many methods employed to estimate creatinine clearance. To improve accuracy researchers have recommended additional adjustments to the CG equation to address inaccuracies at weight extremes (Brown, 2013 & Winter, 2012). Additional weight adjustments are made based on Body Mass Index (BMI), to include ideal body weight (IBW) and adjusted body weight (ABW). The weight adjustments are not included in this tool. Refer to the Creatinine Clearance with adjustment options located on the Explore page.
Rules
Creatinine Clearance (CrCl), mL/min: Cockcroft-Gault Equation
=(140 - age) x (weight, kg) x (0.85 if female) / (72 x Creatinine, mg/dL)
All questions & possible results
Default SectionTitle not visible
Sex
Select one option:
- Female
- Male
Age
A number between 0 and 200, in years.
Weight
A number between 0 and 500, in kg or lbs.
Creatinine
A number between 0 and 50, in mg/dL or µmol/L.
Possible results
Creatinine clearance (Original Cockcroft-Gault)
According to the KDIGO clinical practice guidelines (2012), patients are classified into a CKD stage using both eGFR and albuminuria status. Decreased GFR, increased urinary albumin excretion, or both are considered high risk for progressive kidney disease. Referral to nephrology for further management is indicated for high risk patients.
Literature
- Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. — Cockcroft DW, Gault MH.
- Impact of various body weights and serum creatinine concentrations on the bias and accuracy of the Cockcroft-Gault equation. Pharmacotherapy. 2012 Jul;32(7):604-12. — Winter MA, Guhr KN, Berg GM.
- Functional range of creatinine clearance for renal drug dosing: a practical solution to the controversy of which weight to use in the Cockcroft-Gault equation. Ann Pharmacother. 2013 Jul-Aug;47(7-8):1039-44. — Brown DL, Masselink AJ, Lalla CD.
