Fall Patterns Predict Mortality After Hip Fracture in Older Adults, Independent of Age, Sex, and Comorbidities

Abstract

Falls are the most frequent cause of hip fracture. We aimed to investigate whether specific fall patterns have predictive value for mortality after hip fracture. In this cohort study, data of individuals presented to the Severance Hospital, Seoul, Korea, between 2005 and 2019 due to fragility hip fracture (n = 1986) were analyzed. Fall patterns were defined as causes, activities leading to falls, and a combination of both, based on electronic medical records using pre-specified classification from a prior study on video-captured falls. Mean age of study subjects were 77 years (71% women) and 211 patients (10.6%) died during follow-up (median 544 days). Indoor falls at home had a higher mortality than outdoor falls (11.9 vs. 8.0%, p = 0.009). Among 16 fall patterns, incorrect weight shift while sitting down (adjusted hazard ratio [aHR] 4.03) or getting up (aHR 2.01), collapse during low-risk activity (aHR 2.39), and slipping while walking (aHR 2.90, p < 0.01 for all) were associated with increased mortality compared to outdoor falls, after adjustment for age, sex, and Charlson comorbidity index (CCI), constituting a high-risk pattern. High-risk fall patterns were associated with a higher risk of mortality (aHR 2.56, p < 0.001) than low-risk patterns (aHR 1.37, p = 0.080) and outdoor falls (referent; log rank p < 0.001), which improved mortality prediction when added to a base model including age, sex, and CCI (integrative area under receiver-operating characteristics curve 0.675 to 0.698, p < 0.001). Specific fall patterns were associated with higher mortality in older adults with hip fracture, independent of age, sex, and comorbidities.