Development of a prognostic model to predict post-operative mobility of patients with fragility hip fractures: a retrospective cohort study

Abstract

IntroductionOlder adults with fragility hip fractures have high 1-year mortality and significant functional loss. This study aimed to identify the factors that predict the post-operative ambulatory prognosis of patients with fragility hip fracture. MethodsA total of 233 patients who were consecutively admitted with fragility hip fracture to the orthopaedic unit of an acute hospital in Hong Kong between March and July 2016, were included in this retrospective observational cohort study. The outcome variable was the binary classification of whether patients could or could not walk independently without assistance for more than10 m at the time of discharge from hospital to community. The prognostic model was developed by using multivariate logistic regression. ResultsEighty-nine (38.2%) patients could walk independently upon discharge. The statistically significant factors that affected walking independence on discharge were age (Odds Ratio [OR] = 0.93), Charlson Comorbidity Index (OR = 0.67), baseline Mini-Mental Status Examination score (OR = 1.15) and pre-fracture mobility (p = 0.012). Patients who walked unaided before the fracture had a better prognosis than patients requiring a stick walker (OR = 0.57), quadripod walker (OR = 0.28) or frame walker (OR = 0.12). The area under the ROC curve was 0.848. ConclusionsThe model provides healthcare professionals with evidence to personalize the rehabilitation regime according to the patient's age, comorbidity, baseline cognitive function and pre-fracture mobility.