Table 2. AUC Values for FRAX and OST Estimated Risk of BMD T Score of −2.5 or Less in the BMD Subset (N = 4607)^a.

Outcome	Race and ethnicity	No. of participants	No. of events	AUC (95% CI)b
				FRAX	OST
Femoral neck T score ≤−2.5	All	4607	235	0.72 (0.68-0.75)	0.83 (0.80-0.85)
	Black	628	14	0.74 (0.61-0.87)	0.85 (0.74-0.96)
	Hispanic	320	14	0.74 (0.60-0.88)	0.79 (0.65-0.93)
	White	3642	206	0.72 (0.68-0.75)	0.82 (0.80-0.85)
Any BMD site T score ≤−2.5c	All	4607	653	0.64 (0.62-0.66)	0.74 (0.72-0.76)
	Black	628	130	0.68 (0.63-0.73)	0.76 (0.71-0.81)
	Hispanic	320	37	0.68 (0.59-0.76)	0.76 (0.68-0.84)
	White	3642	484	0.68 (0.65-0.70)	0.75 (0.73-0.78)

Abbreviations: AUC, area under the receiver operating characteristic curve; BMD, bone mineral density; FRAX, Fracture Risk Assessment Tool; OST, Osteoporosis Screening Tool.

^a All models are adjusted for current hormone therapy use (yes or no) and the Calcium plus Vitamin D Trial intervention assignment (active, placebo, or not randomized). Because only 1 Asian participant had a femoral neck BMD T score of −2.5 or less, we do not display results for Asian participants.

^b Femoral neck AUC comparisons by race and ethnicity are as follows. For FRAX, P > .99 for Black vs Hispanic women, P = .77 for Black vs White women, and P = .79 for Hispanic vs White women. For OST, P = .50 for Black vs Hispanic women, P = .60 for Black vs White women, and P = .67 for Hispanic vs White women. For comparison of FRAX AUC vs OST AUC at the femoral neck within each racial and ethnic group, P < .001 for all participants, P = .22 for Black women, P = .61 for Hispanic women, and P < .001 for White women. Any BMD site AUC comparisons by race and ethnicity are as follows. For FRAX, P = .96 for Black vs Hispanic women, P = .86 for Black vs White women, and P = .96 for Hispanic vs White women. For OST, P = .96 for Hispanic vs White women, P = .74 for Black vs White women, and P = .88 for Hispanic vs White women. For comparisons of FRAX AUC vs OST AUC at any BMD site within each racial and ethnic group, P < .001 for all participants, P = .03 for Black women, P = .19 for Hispanic women, and P < .001 for White women. P values were calculated using a χ² statistic on 1 df testing the difference between each paired group.

^c Includes femoral neck, total hip, or lumbar spine.