Impact of stroke history on the risk of recurrent hip fracture or major osteoporotic fractures among patients with incident hip fracture. A nationwide cohort study.

Considerable uncertainty regarding risk factors for recurrent fracture among older patients with hip fracture prevails. We aimed to investigate the relationship between prefracture stroke history, baseline mobility and the risk of recurrent hip fracture. This cohort study was based on the Danish Multidisciplinary Hip Fracture Registry, 2011 - 2018 (n = 48,230). We estimated cumulative incidence (competing risk of death) of recurrent hip fracture and major osteoporotic fractures within one- and two years comparing patients with/without prefracture stroke history. Analyses were performed overall and stratified on baseline mobility status (good mobility: Cumulated Ambulation Score ≥ 5 vs. poor mobility: Cumulated Ambulation Score < 5). Using Cox r egression, adjusted cause-specific hazards ratios (HR) with 95% confidence intervals (CI) were obtained. One-year cumulative incidence was 4.6% (95% CI: 3.9-5.4) among patients with stroke history and 4.3% (95% CI: 4.1-4.5) among patients without stroke history. For patients with good mobility, the cumulative incidence of recurrent hip fracture was 5.8% (95% CI: 4.3-7.5) vs 3.7% (95% CI: 3.4-4.0) for patients with vs. without stroke history. Corresponding numbers for patients with poor mobility were 4.4% (95% CI: 3.6-5.5) and 5.0% (95% CI: 4.7-5.3). Stroke history was associated with an adjusted HR of 1.55 (95% CI: 1.15-2.10) for recurrent fracture among patients with good mobility. In contrast, no association was observed among patients with poor mobility (adjusted HR 0.88 (95% CI: 0.70-1.10)). The associations were attenuated after two years of follow-up and for major osteoporotic fractures. In conclusion, stroke history was associated with slightly higher risk of recurrent fracture among patients with first-time hip fracture in the overall analysis, although the confidence interval included a null result. The association was modified by baseline mobility: Patients with stroke history and good mobility had a markedly higher risk, whereas patients with stroke and poor mobility did not. This article is protected by copyright. All rights reserved.