COVID-19 increases the risk for hip fractures in older subjects - A register-based Swedish population study

Hip fractures are a significant public health concern, associated with high morbidity and mortality. This population-based cohort study investigated whether COVID-19 increased hip fracture risk in Swedish adults. The study included 3,931,893 Swedish residents aged ≥50 years as of January 1st 2020, and recorded 50,883 incident hip fractures during follow-up, until the end of 2022. The exposure of interest was COVID-19 confirmed via national registries during the study period, with 711,879 (18.1%) identified cases. The primary outcome was hip fracture incidence. Secondary outcomes included fractures of the proximal humerus and wrist. Association between COVID-19 and fractures was estimated using Cox proportional hazards regression with time-varying exposure, adjusting for demographic and socioeconomic characteristics, frailty index, previous comorbidities, prior medication use, and COVID-19 vaccination status. Results were presented as hazard ratios (HRs) with 95% confidence intervals (CIs). In fully adjusted models, COVID-19 was associated with a 43% higher risk of hip fractures (HR 1.43, 95% CI 1.36-1.50), with stronger association observed in men (HR 1.57, 95% CI 1.45-1.71) than in women (HR 1.36, 95% CI 1.28-1.45). Age-stratified analyses revealed significant associations in individuals aged ≥65 years (men: HR 1.68, 95% CI 1.54-1.82; women: HR 1.42, 95% CI 1.33-1.51), but not in those aged 50-65 years. Associations with proximal humerus and wrist fractures were less pronounced. These findings suggest that COVID-19 is associated with a substantially increased risk of hip fracture, especially among individuals aged ≥65 years old, underscoring the importance of targeted fracture prevention in this group after COVID-19.