Evaluation of the Burden of Bone Fractures in People Living With Haemophilia: A Registry‐Based Matched Cohort Study

Background: Bone diseases, such as low bone mineral density and osteoporosis is an emerging concern in people with haemophilia (PWH). As a consequence, PWH might experience fractures more frequently than the general population. Our primary aim was to compare the incidence of bone fractures in PWH and controls without bleeding disorders. The secondary aim was to identify factors associated with fractures in PWH. Methods: This was a retrospective, matched cohort, study based on data from the Canadian Bleeding Disorders Registry and data from the Institute for Clinical Evaluative Sciences (ICES). PWH were eligible if alive on 1 January 2017. They were followed up to 31 March 2018. Age- and sex-matched controls were randomly selected with a 20:1 ratio. We analysed the data using multivariate regression models, adjusting for age, severity, inhibitor status, and comorbidities (Charlson Comorbidity index). Results: 1080 PWH and 21,597 controls were included. 8.7% of PWH and 5.7% of controls experienced a fracture during the follow-up period. The adjusted hazard ratio (aHR) for a fracture was 1.46 [95% confidence interval (CI) 1.19; 1.80] in PWH. Severe haemophilia [adjusted odds ratio (aOR) 1.72, 95% CI 1.02; 2.93] and the presence or history of an inhibitor (aOR 2.42, 95% CI 1.08; 5.42) were risk factors for a fracture, after adjusting for age and comorbidities. Conclusions: PWH have a higher risk of bone fractures than the general population. Amongst PWH, the severity of haemophilia and the presence or history of an inhibitor are risk factors for a bone fracture.