To calculate the Cockcroft-Gault formula for women, what additional step is necessary after the main calculation?

To calculate the Cockcroft-Gault formula for women accurately, the additional step required after the main calculation is to multiply by 0.85. This adjustment is made because women typically have a lower body mass and muscle mass compared to men, which can affect the estimation of creatinine clearance. The main calculation provides an estimate of renal function based on serum creatinine, age, weight, and height, but the multiplication by 0.85 is necessary to account for the physiological differences between genders.

This step helps to ensure that the calculated renal function more accurately reflects the actual kidney function in women, aligning the estimate closer to clinical reality. Such adjustments in formulas are common in medical calculations to enhance accuracy, particularly when gender differences are known to impact the underlying biological variables being measured.