Outcomes in older patients after surgical treatment for hip fracture: a new approach to characterise the link between readmissions and the surgical stay.

Objectives: to identify factors associated with readmissions related to the index surgical stay. Design: retrospective cohort study. Setting: administrative claims databases. Subjects: patients over 75 surgically treated for hip fracture in Paris area. Methods: we analysed all admissions in 2005, and tracked for 1-year readmissions. First readmissions (FRs) were classified as related or unrelated to the index stay, according to rules defined a priori. We analysed the association between patient characteristics and the FR. Results: among 5,709 patients, 32% had at least one readmission, 53% were FR related. Near 80% of related readmissions occurred within 3 months from discharge. Surgical conditions caused 47% of all related readmissions, and male gender, dementia, cancer or kidney diseases were independent risks factors. Conclusions: half of readmissions could be classified as related to the index stay and a great majority of these occurred early post discharge. Surgical conditions caused 47% of all related readmissions. Improvement in orthopedic-geriatric co-care is suitable to expect an impact on outcomes after surgery.