FRAX 10-year fracture risk in rheumatoid arthritis assessed with and without bone mineral density – are we treating our patients under bDMARDs?

Objective: This study aimed to identify the rheumatoid arthritis (RA) patients under biological therapy who have FRAX® scores classified as high fracture risk and to evaluate if they are receiving treatment for osteoporosis (OP). The authors also investigated the intra-individual agreement between FRAX® fracture risk calculated with and without bone mineral density (BMD). Methods: A single-center retrospective cohort study was performed in a total of 303 patients with RA under biologics. Demographic and clinical data were collected using Rheumatic Diseases Portuguese Register (Reuma.pt), complemented with data from the hospital clinical records. FRAX scores with and without BMD were calculated. The Kendall's Tau coefficient was used to assess the agreement between FRAX risk categories. Correlations were evaluated by the Spearman test. Comparisons of distributions from independent variables used the Mann-Whitney test. Results: When FRAX® score was calculated without BMD (n=303), 25% patients were categorized as high fracture risk. Among them, only 54% were receiving OP treatment. FRAX® assessment with BMD (n=231) identified 33% patients with high fracture risk, 52% in treatment for OP. Thirty patients (21%) previously classified as low fracture risk using FRAX® without BMD were recategorized as high risk (𝜏=0.570, p<0.001). Despite that, there was a strong correlation between fracture risks assessed with and without BMD. Conclusion: The authors highlight the high number of patients, around 50%, who are not receiving treatment according to FRAX categorization. There is a discordance in fracture risk categorization, as one-fifth of low-risk patients according to FRAX without BMD were reclassified as high-risk after FRAX recalculation with BMD data, raising the need to request a dual-energy X-ray absorptiometry not only for patients classified as having an intermediate risk of fracture, but also for low-risk patients.