Context: No generally accepted thresholds for quantitative ultrasound (QUS) parameters to screen individuals at high risk of osteoporotic fractures have been defined.
Objective: We sought to define appropriate cutoff points for osteoporotic fractures of calcaneus ultrasound according to participants' prevalent osteoporotic fractures.
Design and setting: This was a cross-sectional, population-based study conducted in Shanghai, China.
Participants: A total of 9352 Chinese women and men aged 40 and older were studied.
Main outcome measures: We measured calcaneus QUS (Achilles Express, GE Lunar) values and their relationships with osteoporotic fractures.
Results: A prevalence of 14.9 and 12.2% of osteoporotic fractures was found in the women and men (P<0.001), respectively. Subjects with osteoporotic fractures had significantly lower QUS values than those without (P<0.001). One sd decline in the stiffness index (SI)-derived T-score was associated with a high risk of nonvertebral fracture [odds ratio (OR)=1.50; 95% confidence interval (CI), 1.39-1.62; P<0.001], clinical vertebral fracture (OR=1.49; 95% CI, 1.18-1.90; P<0.01), and multi-fractures (OR=1.98; 95% CI, 1.63-2.40; P<0.001). The receiver operating characteristic analysis showed that QUS could differentiate osteoporotic fractures in postmenopausal women and men, but not in premenopausal women. The optimal cutoff points for the SI-derived T-score to detect a high risk of nonvertebral fractures, clinical vertebral fractures, and multi-fractures were -1.25, -1.55, and -1.80 in postmenopausal women, respectively, and -1.30, -1.90, and -2.00 in males, respectively.
Conclusions: As a screening tool, the SI-derived T-score obtained from the Achilles QUS device for a postmenopausal woman or man that is less than -1.25 and -1.30, respectively, may indicate an increased risk of osteoporotic fractures and should be further evaluated by central DXA.