Table III.

Stratified correlations between PBF_DXA, BMI, and SF sum

	Boys		Girls
	BMI	SF sum	BMI	SF sum
Overall	0.83*	0.91*	0.84*	0.89*
Age group, years
8-11.9	0.86*	0.92*	0.84*	0.90*
12-14.9	0.78*	0.91*	0.86†	0.90†
15-17.9	0.84*	0.90*	0.83†	0.87†
18-19.9	0.87†	0.91†	0.89	0.88
Race
Non-Hispanic whites	0.83*	0.91*	0.85*	0.89*
Non-Hispanic blacks	0.84*	0.92*	0.85*	0.91*
Mexican-Americans	0.86*	0.93*	0.82*	0.90*
Body fatness‡
<Median	0.49*	0.68*	0.59*	0.75*
≥Median	0.76*	0.84*	0.77	0.79

P values assess whether the correlation between PBF_DXA and BMI is equal to the correlation between PBF_DXA and the SF sum.

^*P < .001;

^†P < .05. In a random sample of 3500, a correlation of 0.055 would be statistically significant (H₀: r = 0) at the 0.001 level.

^‡Body fatness was categorized into 2 groups on the basis of the median PBF_DXA for a child’s sex, age (year), and imputation number.