A Swedish national register study on the association between dementia, walking ability and survival after a hip fracture

Abstract

Abstract Background: The association between dementia, hip fractures, and subsequent walking ability remains unclear. This study aims to investigate the relationship between hip fractures and the loss of walking ability, as well as mortality, by comparing patients with and without dementia. Methods: This was a register study with data obtained from the Swedish Hip Fracture Register and linked to information from other national registers. All adults 60 years or older who suffered a hip fracture in Sweden between 2010 and 2018 were included. A four-month follow-up was conducted using a questionnaire or telephone interview. Binary logistic regression was used to analyze the loss of walking ability, and multivariate Cox regression was used to analyze survival after four months while adjusting for conventional factors. The analysis of loss of walking ability was stratified into four groups based on prefracture walking ability: Alone outdoors, Only with company outdoors, Alone indoors, and Only with company indoors. Results: The analysis of walking ability included 59,402 cases, of which 17% had dementia. The analysis of survival included 111,353 cases, 22% of which had dementia. Patients with dementia had a significantly higher risk of complete loss of walking ability after four months, with adjusted ORs of 2.34 for Alone outdoors, 1.53 for Only with company outdoors, 1.41 for Alone indoors, and 1.29 for Only with company indoors. Dementia was also associated with a higher four-month mortality risk (adjusted HR 1.26, 95% CI 1.22–1.31). Conclusions: The impact of dementia on the risk of complete loss of walking ability after a hip fracture varies widely depending on prefracture walking ability. Patients with dementia with high walking ability prior to the fracture are at most risk when compared to patients without dementia. In addition, dementia is also an independent risk factor for mortality following a hip fracture. These findings have implications for guiding future investigations and equipping clinicians with knowledge regarding the risks their patients may encounter.