Mortality following hip fracture surgery in patients with dementia: a Swedish multiple national register study

PURPOSE: Hip fractures in older adults are a significant risk factor for morbidity and mortality, with the presence of dementia further complicating outcomes. The purpose of this study was to investigate the association between hip fractures and mortality of patients with dementia and dementia types in comparison to those without dementia following hip fracture surgery. METHODS: Utilizing data from the Swedish Hip Fracture Register (SHR), Swedish Registry for Cognitive/Dementia Disorders (SveDem), National Patient Register (NPR), and National Prescribed Drug Register (PDR), we conducted a retrospective analysis of 111,353 patients aged 65 and older who underwent hip fracture surgery between 2010 and 2018. Patients were categorized into two cohorts: those with and without a known diagnosis of dementia prior to the hip fracture. Multivariable Cox regression analyses were used to evaluate mortality risk factors. RESULTS: Of the study sample, 22% had dementia. Dementia patients exhibited higher mortality rates at 30 days with 13% vs. 6%, (p < 0.001), 4 months with 27% vs. 12%, (p < 0.001) and at 1 year with 39% vs. 20%, post-fracture (p < 0.001). Higher ASA grades, poor baseline walking ability, and long-term care residency were also associated with increased mortality. Parkinson's disease dementia was associated with a higher mortality compared to other dementias during the first 4 months post-operatively. CONCLUSION: Our findings revealed an association between dementia diagnosis and higher risk of mortality following hip fracture surgery. These findings underscore the need for specialized post-operative care. Involving specific post-operative geriatric competence, such as orthogeriatric or orthogeriatric models of care could potentially improve outcomes. Further research is needed to explore the impact of dementia severity and subtype on mortality.