Validating the FRAC-Stroke score: targeting those at highest risk of fracture

Fracture risk is increased after stroke, but there is a lack of specific, effective tools to screen and prevent minimal trauma fractures (MTF) post-stroke. While the Fracture Risk after Ischemic Stroke score (FRAC-Stroke score), developed to predict fracture risk post-stroke, shows promising performance, it has not yet been widely adopted or validated in large cohorts outside of Canada. We aimed to: (1) evaluate the reliability and validity of the FRAC-Stroke score in predicting MTF and (2) determine the optimal score to classify patients at highest fracture risk following ischemic stroke. A retrospective cohort study was undertaken using data from the PRECISE study, which included person-level linked administrative data from the Australian Stroke Clinical Registry (AuSCR, 2014-2016). The FRAC-Stroke score at hospital discharge was determined for survivors of ischemic stroke, aged >50 yr, using coded comorbidities derived in the prior 5-yr period and modified Rankin Scale. Fine-Gray models were built to evaluate associations of the FRAC-Stroke score with MTF within 12 mo post-discharge, accounting for death as the competing risk. Among 4545 adults, the median FRAC-Stroke score was 8 (IQR 5-11) and 118 patients (2.6%) sustained a MTF within 12 mo post-discharge. The optimal FRAC-Stroke score cut-point to stratify MTF risk was 11.5, with a c-statistic of 0.70. Participants with a FRAC-Stroke score ≥12 (vs <12) had a 5.5-fold increased risk of MTF (CI 3.8-7.9, p < .01). When stratified by quintiles of FRAC-Stroke score, those in quintile 5 (FRAC-Stroke score ≥ 14) had a 15.2-fold increased risk of MTF than those in quintile 1 (FRAC-Stroke score < 3; CI 6.6-35.2, p < .01). The FRAC-Stroke score reliably identifies increased fracture risk in the Australian ischemic stroke population, with a score of 12+ able to discriminate those at high risk of fracture.