Comparison of osteoporosis self assessment tool for Asian (OSTA) and standard assessment in menopause clinic, Chiang Mai

Abstract

Objective: To compare osteoporosis self assessment tool for Asian (OSTA) with the standard measurement of bone mineral density (BMD) by dual energy x-rays absorptiometry (DXA) in identifying the prevalence of osteopenia and osteoporosis in Thai menopausal women who attended the Menopause Clinic, Faculty of Medicine, Chiang Mai University. Material and Method: The data was retrospectively collected from the medical records of women who had lumbar, femoral neck and radius BMD t-score measurement by DXA (Hologic®, QDR-4500C) between January 2004 and December 2005. The body weight and age of patients were calculated for the OSTA index score. The women with OSTA score < -1 and ≥ -1 were classified as "moderate to high risk" and "low risk" for fracture, respectively. The BMD T-scores of < -1 and ≥ -1 were classified as "osteopenia to osteoporosis" and "normal" respectively. Results: Three hundred and fifteen menopausal women of the age of 45-87 years were included. The BMD Tscores assessment revealed that more than half of the subjects had osteopenia to osteoporosis (T-score ≤ -1), 196 women (62%) at lumbar spine, 133 women (42.2%) at femur and a third, 114 women (36.2%) at radius respectively. The OSTA index at the standard cut-point of < -1 had a sensitivity and specificity of 36.2% and 71.4% respectively for the lumbar spine and 40.6% and 72.0% respectively for the neck of the femur in predicting osteopenia to osteoporosis status. Conclusion: The OSTA index score had a low sensitivity (36-48%) but a high specificity (71-75%) for identifying osteopenic to osteoporotic women among population of menopausal period. Nevertheless, it is a useful screening tool in old age women (> 65 years).