The risk of femoral fracture is increased in patients with ischemic stroke and transient ischemic attack-a population-based observational secondary analysis of the Austrian stroke cohort.

Abstract

Background: An increased risk of femoral fractures after ischemic stroke (IS) and transient ischemic attack (TIA) has been shown previously. However, it remains unclear whether the ischemic cerebral event is directly associated with the risk of femoral fractures.

Aims: The aim of this study was (1) to assess the association between the frequency of femoral fractures in patient with IS and TIA, and (2) to compare the risk of femoral fractures to the Austrian general population.

Methods: Population-based observational secondary analysis of the Austrian Stroke Cohort to assess the incidence of femoral fractures in the year after IS/TIA compared with the year before, and both intervals compared with the Austrian general population. All patients ⩾20 years treated for IS/TIA in Austria between 1 January 2016 and 31 December 2018 were identified using medical record linkage. Patient trajectories were reconstructed from 1 January 2015 to 31 December 2019 to have a 1-year observational period before and after the event. Femoral fractures within 1 year after IS/TIA compared to 1 year before IS/TIA were analyzed using McNemar test and Cox regression analysis considering sex and age. The 1-year age- and sex-adjusted relative risk of femoral fractures was calculated for patients with IS/TIA and compared to the Austrian general population.

Results: A total of 48,996 survivors of IS (n = 34,997) and TIA (n = 13,999) were included. The incidence of femoral fractures increased significantly from the year before the IS/TIA (8.9 per 1000 person-years, 95% CI 7.7-10.2) to the year after the event (11.8 per 1000 person-years, 95% CI 10.1-13.5; p = 0.022). Compared to the Austrian general population including 21.1 million patient-years at risk and 37,436 femoral fractures, the risk of femoral fractures was increased both in the year before (RR 2.08, 95% CI 2.06-2.11) and after (RR 3.52, 95% CI 3.48-3.56) the IS/TIA.

Conclusion: The risk of femoral fractures was found to be increased in the year following an IS/TIA, indicating a direct association with the IS/TIA event.Data access statement:Reconstruction of medical record linkage and individual patient trajectory reconstruction were reported previously. Data from individual patient trajectories was used for this analysis.