Table 3.

Prediction of 24-hour urine creatinine excretion in the discovery cohort (n = 9199)

Model	AIC, women	AIC, men	Adjusted R-squared	Deviance	P-value
Adjustment for sex and study cohort	65,070	70,573	0.205	849	<0.001
Add weight (w)a	64,504	69,841	0.275	764	<0.001
Add height (h)a	64,282	69,786	0.309	717	<0.001
Add age (a)a,b	64,068	69,661	0.328	691	<0.001
Add height × weight interaction term	64,068	69,663	0.329	691	0.336
Add serum creatinine concentration (s)c,d	63,606	69,137	0.336	672	<0.001

AIC, Akaike Information Criteria.

^aSelected functional forms are inverse of weight for both sexes; inverse of height squared for both sexes; age squared for women and age cubed for men.

^bFinal demographic and anthropometric model (model 1). Formulas are: Females: log(E[creatinine]) = 8.1–35.1∗w⁻¹–14,526∗h⁻²–0.5∗a². Males: log(E[creatinine]) = 8.2–54.1∗w⁻¹–7885∗h⁻²–0.4∗a³.

^cSerum creatinine concentrations modeled as natural splines with knots at 0.7, the median and the 75^th percentile for women and knots at 0.9, the median and the 75^th percentile for men.

^dFinal demographic, anthropometric, and serum creatinine model (model 2; n = 9143 participants with nonmissing serum creatinine values).