A non-invasive prevention program model for the assessment of osteoporosis in the early postmenopausal period: a pilot study on FRAX(®) and QUS tools advantages.

Objective: The study analyses the performances of FRAX algorithm and quantitative ultrasound (QUS) tool in relationship to the dual-energy X-ray absorptiometry (DXA) categorization to identify patients at risk of osteoporosis during menopause and to reach new thresholds for recommending the first DXA examination.

Design: Retrospective cohort study.

Patients And Measurements: Two hundred eighty-two postmenopausal patients filled out a questionnaire which determined their FRAX index and performed a bone evaluation by QUS of the calcaneus to determine their stiffness index (SI). Thereafter, they underwent assessments by the gold-standard DXA bone examination.

Results: Statistically significant correlations were observed between FRAX (calculated without BMD) and both QUS and DXA diagnosis. FRAX mean indices of risk corresponding to the diagnosis of osteoporosis by QUS and DXA were similar. Receiver operating characteristic (ROC) curve analysis showed that both FRAX and QUS tests were sufficiently accurate in predicting the alteration of bone mineral composition. The ROC curves of QUS allowed us to identify, in our population, SI cutoff for normal patients (SI > 90.5) and for patients having osteoporosis (SI < 78.5). We selected a cutoff screening value from FRAX ROC curve for major clinical fracture (2.94). The following diagnostic algorithm demonstrated that the use of FRAX test alone has a sensitivity of 85.3 % and a specificity of 33.8 % while the use of QUS exam alone showed a sensitivity of 81.3 % and a specificity of 45.1 %. When considering the capacity of QUS exam in combination with FRAX test, the final algorithm showed a sensitivity of 69.4 % and a specificity of 57.7 %.

Conclusions: The use of QUS test with adjusted cutoffs offers a similar performance to the FRAX test alone in terms of sensitivity. The combined use of the tests reduces the sensibility but increases the specificity and adds clinical information related to the bone status of the patient.