Osteoarthritis and the incidence of fracture in the United Kingdom: a retrospective cohort study of 258,696 patients

Objective: The goal of this study was to analyze the relationship between osteoarthritis and the incidence of fracture in men and women aged >18 years followed in general practices in the United Kingdom. Methods: This study included patients aged >18 years who had received an initial diagnosis of osteoarthritis in one of 256 general practices in the United Kingdom between January 1997 and December 2016 (index date). Patients without osteoarthritis were matched (1:1) to those with osteoarthritis by sex, age, index year, diabetes, dementia, corticosteroid therapy, and practice. For patients without osteoarthritis, the index date was a randomly selected visit date between 1997 and 2016. The association between osteoarthritis and the incidence of fracture was investigated using Kaplan-Meier curves and conditional Cox regression analyses. Results: This retrospective cohort study included 129,348 patients with osteoarthritis and 129,348 patients without osteoarthritis [60.1% women; mean (standard deviation) age 63.7 (14.0) years]. After 10 years of follow-up, 12.1% of individuals with osteoarthritis and 7.7% of those without osteoarthritis had suffered at least one fracture (log-rank P-value<0.001). There was a positive and significant association between osteoarthritis and fracture in the overall sample [hazard ratio (HR) = 1.55, 95% confidence interval (CI) = 1.50-1.60]. These findings were corroborated in all sex, age, and osteoarthritis joint site subgroups. Conclusion: Intervention is urgently needed to reduce the risk of fracture in adults with osteoarthritis, and further research is warranted in order to gain more of an insight into the mediators involved in the relationship between osteoarthritis and fracture. (c) 2020 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.