BackgroundHip fracture is a common event in older adults, leading to an increased risk of mortality, disability, and higher healthcare costs. Early in-hospital rehabilitation after surgery within orthogeriatric units may improve outcomes with limited incident complications even in the oldest old. We aimed to determine the prevalence and predictors of non-adherence to early rehabilitation in the orthogeriatric unit of an Italian tertiary hospital and its impact on outcomes and setting at discharge.MethodsRetrospective observational single-centered cohort study. Patients aged ≥ 65 years admitted to the orthogeriatric unit for hip fracture who underwent surgery between April 2019 and October 2020 were considered eligible if able to walk autonomously or with assistance and independent in at least 2 Basic Activities of Daily Living. Along with sociodemographic and geriatric variables, characteristics of surgery and rehabilitation, in-hospital complications and functional outcomes at discharge were collected. The primary outcome was non-adherence to the early in-hospital rehabilitation program.ResultsAmong 283 older patients (mean age 82.7 years, 28.6% male), non-compliance with physical therapy was assessed in 49 cases (17.3%), characterized by worse pre-fracture clinical, cognitive, and functional status and showing worse outcomes in terms of mobilization at discharge. After multivariable analysis, non-adherence was independently associated with the onset of delirium (OR 5.26, 95%CI 2.46–11.26; p < 0.001) or infections after surgery (OR 3.26, 95%CI 1.54–6.89; p < 0.001) and a systolic blood pressure at admission < 120 mmHg (OR 4.52, 95%CI 1.96–10.43, p < 0.001).ConclusionsPre-fracture poor cognitive and functional status, along with lower systolic blood pressure, seem to make some patients more vulnerable to in-hospital complications (mainly delirium and infections) and negatively affect the adherence to physical therapy and, by consequence, clinical outcomes of rehabilitation.