Dementia is Associated with an Increased Risk of Hip Fractures: A Nationwide Analysis in Korea

Background and Purpose Dementia has been reported to be associated with an increased risk of hip fracture, but few case-control studies have been performed to actually confirm this. This study investigated the association between dementia and hip fracture by comparing the risk of hip fracture between subjects with and without dementia. Methods We examined a population-based matched cohort from the National Health Insurance Service-Senior Cohort data set that covers approximately half a million recipients of medical insurance in South Korea. Subjects with new clinically verified dementia during 2003-2007 were included, and five subjects without dementia were matched for age, sex, and index year to each subject with dementia as the controls. The risk of hip fracture for dementia was evaluated up to 2015 using Cox regression analysis. Results During the 12-year follow-up period, 284 subjects with dementia (10.66%) and 603 subjects without dementia (4.53%) experienced hip fractures. Dementia was independently associated with a higher risk of hip fracture [hazard ratio (HR)=2.840, 95% CI=2.449-3.293] and the adjusted HR for hip fracture in the subjects with dementia was highest within 2 years after the initial diagnosis (HR=2.862, 95% CI=2.053-3.990). Conclusions This study found that dementia could be an independent risk factor for hip fracture even at the early stage. This necessitates consideration of the future risk of falls and balance deficits in terms of physical activity after a diagnosis of dementia.