Table 2.

ANOVA models

	Model 1		Model 2		Model 3		Model 4
	F	Effect	F	Effect	F	Effect	F	Effect
Constant		6.47		6.42		6.55		5.9
Body mass index, kg/m2	295*	−0.14	294*	−0.14	364*	−0.15	170*	−0.08
Sex	99*	Men = −0.054	102*	Men = −0.056	73*	Men = −0.045	8*	Men = −0.012
Age, yr	32*	−0.167	25*	−0.186	25*	−0.159	113*	−0.266
Creatinine clearance			4		186*	0.04	19*	0.01
Urine ammonia					659*	−0.12
Urine sulfate							839*	−0.1
Gastrointestinal anion							6,299*	0.16
Serum total CO2							25*	0.09
Age × sex	3	†	3	†	4	†	4*	†
Multiple R2		0.084		0.085		0.156		0.498

^*Significance at P < 0.01; all effects except age were per 10 units of the variable; effects for age were the linear contrast slope.

^†Many cross products use sex, not shown for lack of important contribution to the model.