Table 4.

Specificity, sensitivity, and AUC of OSTA in identifying subjects at risk of osteoporosis defined by QUS according to sex and age group

Cut-off	Sex	Age group (years)	n	Sensitivity (%)	Specificity (%)	AUC	95% CI	p-value
QUS T-score	Male	50–59	82	5.0	97.6	0.513	0.387–0.639	0.838
≤−1		60–69	146	19.8	86.7	0.532	0.438–0.627	0.509
OSTA		≥70	55	79.3	57.7	0.685	0.541–0.829	0.019
≤−1		Overall	283	27.1	84.4	0.557	0.491–0.624	0.097
	Female	50–59	162	20.0	87.9	0.539	0.444–0.635	0.414
		60–69	141	60.3	56.4	0.584	0.489–0.678	0.088
		≥70	59	94.9	20.0	0.574	0.414–0.735	0.353
		Overall	362	54.8	69.3	0.620	0.562–0.679	<0.001
	Total	50–59	244	13.7	90.6	0.521	0.447–0.596	0.572
		60–69	287	36.9	69.6	0.532	0.466–0.599	0.343
		≥70	114	88.2	41.3	0.648	0.541–0.754	0.008
		Overall	645	41.0	75.1	0.581	0.536–0.625	<0.001
QUS T-score	Male	50–59	82	0.0	100.0	0.500	0.288–0.712	1.000
≤−2.5		60–69	146	5.9	100.0	0.529	0.377–0.682	0.694
OSTA		≥70	55	0.0	98.0	0.490	0.227–0.753	0.942
≤−4		Overall	283	3.3	99.6	0.515	0.403–0.626	0.792
	Female	50–59	162	0.0	100.0	0.500	0.242–0.758	1.000
		60–69	141	37.5	94.7	0.661	0.433–0.890	0.126
		≥70	59	75.0	74.4	0.747	0.602–0.892	0.004
		Overall	362	51.7	94.6	0.732	0.616–0.848	<0.001
	Total	50–59	244	0.0	100.0	0.500	0.338–0.662	1.000
		60–69	287	16.0	97.3	0.567	0.439–0.694	0.271
		≥70	114	57.1	87.1	0.721	0.586–0.856	0.002
		Overall	645	27.1	96.8	0.619	0.534–0.705	0.002

Notes: The table indicates the performance of OSTA at standard cut-off values (−1 for medium risk, −4 for high risk of osteoporosis) in identifying the outcomes of QUS (−1 for medium risk, −2.5 for high risk of osteoporosis) using ROC based on sex and age group. AUC, sensitivity, and specificity values are shown. Bolded p-values are statistically significant (p<0.05).

Abbreviations: AUC, area under the curve; OSTA, osteoporosis self-assessment tool for Asians; QUS, quantitative ultrasound; ROC, receiver-operating curve.