Early rehospitalization after hip fracture in elderly patients: risk factors and prognosis

Introduction Hip fracture usually occurs in older patients. These patients remain at risk for developing new medical complications even after discharge from the hospital. The objective of this study was to identify risk factors for hospital readmission 30 days after hip fracture and the prognosis of the readmitted patients. A prospective, observational cohort study of 732 consecutive patients over 65 years surgically treated for hip fracture and discharged alive in 2010-2014 was conducted. The measurements were patient demographic characteristics, residential and discharge status, Katz Index, Merle D'aubign, Hip Score, Mini-Mental Test, comorbid conditions, Charlson Index, ASA group, type of fracture and repair, and postoperative complications. Patient characteristics were tested by bivariate and multivariate analyses. 8.3 % of patients were readmitted within 30 days (56.0 % of these within 2 weeks). Medical reasons were 13 times more frequent than surgical reasons. Diagnoses more prevalent for readmission were pulmonary disease, deep vein thrombosis, heart failure, and renal failure. Predictors of readmission were female gender (HR 1.9, 95 % CI 1.1-3.4), grade III-IV ASA (HR 2.1, 95 % CI 1.1-4.2), and pre-existing pulmonary disease (HR 5.3, 95 % CI 3.4-9.6). In-hospital mortality among readmitted patients was 22.9 %. In bivariate analyses, male gender, ASA III-IV, cognitive impairment, and more than two comorbidities were potential predictive factors for readmission, and in multivariate analysis only male gender and ASA III-IV. Mortality risk among readmitted patients was significantly higher compared to the in-hospital mortality in the overall cohort (OR 1.8, 95 % CI 1.5-2.3). Hospital readmissions after hip fracture were mainly due to medical complications and a fraction of these may be preventable. Readmission was associated with increased morbidity and mortality.