Prediction of readmissions in the first post-operative year following hip fracture surgery

Purpose: To define risk factors for rehospitalization following fragility hip fractures and to create a predictive model. Methods: A retrospective cohort study of patients 65 years and older, who were treated operatively following fragility hip fractures between 01.2011 and 06.2016. Patients were allocated into two study groups based on the occurrence of recurrent hospitalizations in the year following surgery. Demographic information, comorbidities, and in-hospital characteristics were collected, as was information regarding 1-year readmissions. Multivariate analysis of factors predictive of rehospitalizations was performed, followed by a logistic regression using all predictors with p < 0.05. A stepwise backwards elimination method was used to create the predictive model. Results: Eight hundred and fifty-one patients were included; 369 (43.4%) had recurrent hospitalizations within the first post-operative year. Patients who were rehospitalized were more likely to be males, to use a walking aid and to live dependently. They had a higher age-adjusted Charlson’s comorbidity index (ACCI) score, a higher perveance of atrial fibrillation, lower hemoglobin, worse renal function, less platelets, and longer time to surgery. Prevalence of in-hospital complications was similar. Six variables were found to independently influence the chance for readmissions: male gender, the use of a walking aid, higher ACCI score, lower hemoglobin, atrial fibrillation, and a longer surgical delay. Only the first four were found to be adequate predictors and were added to the prediction formula. Conclusion: High 1-year readmission rates are seen following discharge in patients with fragility hip fractures. Addressing risk factors might aid to better rehabilitate patients and reduce morbidity.