Equations of Gates for Estimating GFR from Serum Creatinine

 

Parameters:

(1) serum creatinine in mg/dL

(2) age in years (with age set to 20 if true age < 20 years)

 

estimated GFR for a male in mL per min per 1.73 square m BSA =

= 89.4 * (((creatinine)^(-1.2)) + (0.005 * (55 - (age in years)) * ((creatinine)^(-1.1))))

 

estimated GFR for a female in mL per min per 1.73 square m BSA =

= 60 * (((creatinine)^(-1.1)) + (0.005 * (56 - (age in years)) * ((creatinine)^(-1.1))))

 

where:

• The 0.005 (rounded up from 0.00475) factor indicates the annual decline in inulin clearance per year, assuming a decline of 4.75% every 10 years.

 

Performance:

• The author compared his method with those of (1) Jeliffe and (2) Cockcroft and Gault. This estimate performed fairly well except at very low and very high GFRs.