Table 5.

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

Ethnicity	Cut-off		Male						Female
	QUS	OSTA	n	AUC	95% CI	p-value	Sensitivity (%)	Specificity (%)	n	AUC	95% CI	p-value	Sensitivity (%)	Specificity (%)
Chinese	≤−1	≤−1	140	0.577	0.482–0.672	0.119	35.8	79.7	208	0.587	0.508–0.665	0.033	62.2	55.1
	≤−2.5	≤−4		0.524	0.376–0.672	0.746	5.6	99.2		0.758	0.619–0.897	<0.001	93.7	57.9
Malay	≤−1	≤−1	110	0.529	0.420–0.637	0.607	17.2	88.5	124	0.668	0.568–0.767	0.001	43.4	90.1
	≤−2.5	≤−4		0.500	0.278–0.722	1.000	0.0	100.0		0.654	0.387–0.921	0.204	97.5	33.3
Indian	≤−1	≤−1	33	0.535	0.335–0.735	0.732	18.8	88.2	30	0.656	0.455–0.858	0.146	50.0	81.2
	≤−2.5	≤−4		0.500	0.221–0.779	1.000	0.0	100.0		0.692	0.374–1.000	0.222	88.5	50.0
Overall	≤−1	≤−1	283	0.557	0.491–0.624	0.097	21.7	84.4	362	0.62	0.562–0.679	<0.001	54.8	63.9
	≤−2.5	≤−4		0.515	0.403–0.626	0.792	3.3	99.6		0.732	0.616–0.848	<0.001	51.7	94.6

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 ethnic 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.