Comparison of Clinical Risk Tools for Predicting Osteoporosis in Women Ages 50-64

The objective of this study was to compare the performance of the US Preventive Services Task Force (USPSTF) recommended WHO Fracture Risk Assessment Tool (FRAX) threshold score of 9.3% (calculated without femoral neck bone density) with the Simple Calculated Osteoporosis Risk Estimate (SCORE), Osteoporosis Self-Assessment Tool (OST), and the Osteoporosis Risk Assessment Instrument (ORAI) to identify osteoporosis in younger women.

We conducted a retrospective review of women ages 50 to 64 years who underwent dual-energy radiographic absorptiometry (DXA) at our institution over a 6-month period. Scores for the FRAX, ORAI, OST, and SCORE tools were calculated using various thresholds: FRAX ≥9.3%, SCORE ≥6, OST <2, and ORAI ≥9. Sensitivity, specificity, and area under the receiver-operating characteristic curve for detection of densitometric osteoporosis by DXA for each tool were compared.

A total of 290 women were identified. Of these, 284 (97.9%) were white, and the mean ± standard deviation age was 56.6 ± 3.4 years. Fifty (17.2%) had osteoporosis of the lumbar spine and/or femoral neck on DXA. Sensitivity, specificity, and area under the receiver-operating characteristic curve for identifying densitometric osteoporosis at the femoral neck and/or spine were 36%, 73%, and 0.55 for FRAX; 74%, 42%, and 0.58 for SCORE; 56%, 69%, and 0.63 for the OST; and 52%, 67%, and 0.60 for the ORAI, respectively.

DXA screening based on the USPSTF-recommended FRAX threshold score of 9.3% has a low sensitivity to identify densitometric osteoporosis in women ages 50 to 64. Lowering the threshold score would increase sensitivity but would also increase the number of women sent for screening DXA. Use of the validated SCORE tool would improve sensitivity to identify osteoporosis in this age group.