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## Taipei Medical University

Skip to 0 minutes and 11 seconds Comparison in the patient population. In terms of body weight again. Cockroft equation tend to overestimate. In the overweight patient, the overestimate is about 15 percent. In diabetes patient, the overestimate is 18 percent. And the diabetic obesity, the overestimate could be as high as 55 percent. Another method by Jelliffe, it is the Jelliffe method. For male is the top formula. Creatinine clearance is equal to 98 minus point 8 times age minus 20 divided by serum creatinine. And for female, the formula says creatinine clearance is equal to 88 minus 0.7 times age minus 20 divided by serum creatinine. Or simply, for the female the value is 90 percent of male. This method was published by the investigator at UCLA Medical Center.

Skip to 1 minute and 30 seconds Another formula Salazar and Corcoran equation for men and for women. For men the top formula and for women the bottom formula. And both formula involves age, weight, height and the serum creatinine. And the formula were derived from overweight population. Therefore, it provides better estimate for obese population. And the formulas were published by investigators at SUNY Buffalo Medical Center. And interestingly, based on these two formula. For men, the maximum life expectancy is 137. And for obese women, the maximum life expectancy is 146. Which is not bad at all. And this is compared also very closely with a hundred forty as suggested by the Cockcroft equation. Schwartz formula is for pediatric patient.

Skip to 3 minutes and 5 seconds It says creatinine clearance is equal to K times height divided by serum creatinine. Now here K is a correction factor or adjustment factor. For example, point three three in Preemie infants. And the point five five in adolescent female. Please pay attention to the unit. Because this kind of formula is the so called empirical formula. You have to apply certain unit for the parameters in the formula. For example, in the Schwartz formula the height must be in centimeter, serum creatinine must be in milligram per decilitre. And the creatinine clearance is in the unit of milliliter per minutes. Now this formula was published by the investigator at University of Rochester Medical Center.

# Other Methods for creatinine clearance estimation

Prof. Lee introduces three other methods for creatinine clearance in this step.

Continuing from the previous step, he says that Cockroft-Gault tends to overestimate the creatinine clearance for those who are overweight, diabetes, or diabetic obesity.

Following that, we learn Jelliffe Method, Salazar & Corcoran Equation, and Schwartz Formula (for children).

In Salazar & Corcoran Equation, we find that the maximum life expectancy for men is 137. Besides, for obese women, the maximum life expectancy is 146. Therefore, it is compared very closely with 140 as suggested by the Cockcroft equation.

In Schwartz Formula, we should notice that the adjustment factor is based on the age of the pediatric patient.

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