Session Type: Poster Session (Tuesday)
Session Time: 9:00AM-11:00AM
Background/Purpose: Applicability of FRAX in Clinical Practice. Results at 10 years
To evaluate the applicability of: 1) the fracture risk thresholds that we proposed in 2013 and 2) a new decision algorithm based on fracture risk calculated by FRAX.
Methods: In 2008, 853 women between 40 and 90 years old referred from Primary Care to the Bone Densitometry Unit were asked to complete a fracture risk factor questionnaire and underwent a bone density scanning (DXA). With FRAX, their absolute risk in the following 10 years of major fracture (MFR) and hip fracture (HFR) was calculated in the following 10 years.
In 2013, we published a proposal of thresholds of high (MFR ≥ 10%) and low (MFR ≤ 3.6%) fracture risk to identify the patients with medium fracture risk in whom a DXA would be indicated.
In 2018, the clinical course of the computerized history of Primary Care was reviewed to identify all bone fractures that occurred in 10 years. In case of doubts about the existence of a fragility fracture, its location or its mechanism of production, the emergency report and/or the bone X-ray was checked.
Results: The final sample is 837 patients; in 10, the follow-up is incomplete and 58 died. In 2008, the mean age of the patients was 61.95 (8.61) years. Eighty percent had at least one fracture risk factor. Twenty percent had normal BMD, 55% osteopenia and 25% osteoporosis. The mean MFR was 6.21% (5.39) and the HFR, 2.08% (3.20).
We identified 243 fractures (168 fragility and 75 traumatic fractures) in 153 patients. 124 patients had a MF (66 vertebral, 39 distal forearm, 10 hip and 9 humerus). Expected MF: 52. 64% of the patients who had MF did not have osteoporosis. 12 patients had a HF. Expected HF: 17.
The area under the ROC curve for MF prediction was 0.643 (95% CI: 0.592-0.694), low prediction capacity. For HR, 0.740 (95% CI: 0.632-0.849), moderate prediction capacity. For BMD in the three locations evaluated, the area was < 0.500, null predictive capacity.
The application of the proposed thresholds classifies appropriately the population with low (331 patients, 40% of the sample, incidence of fracture: 9.36%, 95% CI: 6.22-12.5), medium (357 patients, there would be recommended to perform a DXA in 42% of the sample; incidence of fracture: 16.25%, IC 95%: 12.42-20.07) and high (149, 18%, incidence of fracture: 23.49%, 95% CI: 16.68-30.30) fracture risk defined according to CAROC (< 10%, 10-20%, > 20%).
In patients with medium risk, reclassification to high risk was performed if they had osteoporosis or if the recalculated MFR including the BMD in FRAX calculation algorithm was ≥ 7%.
The result of the application of the algorithm was the classification of 574 patients (69%) as low risk (incidence of fracture: 10.98%, 95% CI: 8.42-13.53) and 263 (31%) as high risk (incidence of fracture: 23.19%, 95% CI: 18.09-28.29). The negative predictive value of fracture in patients classified as low risk is 89%.
Conclusion: The Spanish version of FRAX predicts adequately the HFR and can be used in clinical practice. On the contrary, it underestimates the MFR and should not be used to calculate it. However, in our series, the application of the proposed decision algorithm identifies properly the population with low, medium and high risk of fracture and could be used in clinical practice.
To cite this abstract in AMA style:Marco-Pascual C, Mora M, González-Giménez X, Medina P, Bianchi M, Santo P, Gomez-Vaquero C. Applicability of FRAX in Clinical Practice: 10-year Results [abstract]. Arthritis Rheumatol. 2019; 71 (suppl 10). https://acrabstracts.org/abstract/applicability-of-frax-in-clinical-practice-10-year-results/. Accessed November 28, 2020.
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