Abstract 85: Can OSTA be used as a pan-Indian screening tool in predicting osteoporosis in postmenopausal women? A validation study

Background: The gold-standard for diagnosing osteoporosis-DXA (Dual Energy X-ray Absorptiometry) scan is scarce in India. OSTA score (Osteoporosis Self-Assessment Tool for Asians) = (weight – age)*0.2 predicts risk of osteoporosis and can be used as reference tool for DXA. At a cut-off of≤ 1, OSTA predicted femoral neck osteoporosis with a sensitivity of 88% in a previous study among south-Indian postmenopausal women. This study was done to validate OSTA in postmenopausal women across India. Methodology: A cross-sectional study in 5356 postmenopausal women from four zones of India -South, East, North& West. Bone mineral density (BMD) and trabecular bone score (TBS) were assessed by DXA. Performance of OSTA in predicting BMD & TBS was assessed using ROC curve. Results: The mean (SD) age was 61.6 (7.6) years. The performance of OSTA in predicting osteoporosis was fair (P<0.001) with AUC of 0.727 (95% CI 0.705-0.749) in zone 1, 0.693 (95% CI 0.664-0.723) in zone 2, 0.730 (95% CI 0.700-0.759) in zone 3 and 0.703 (95% CI 0.672-0.735) in zone 4. At a cut-off of 1.0, sensitivity was 76-84% & specificity was 45-50% in diagnosing osteoporosis. In predicting degraded microarchitecture, the AUC was 0.500-0.600. Conclusion: OSTA may be used as a screening tool for women at high risk of osteoporosis.