Risk Factors for 6-month Mortality among the Oldest Old Orthogeriatric Patients

Background and aim: Hip fracture (HF), whose prevalence increases exponentially with age, has been widely described among patients aged ≥65 years. However, less has been published about the oldest old (≥85 years). The aim of our study was to describe the characteristics and investigate the risk factors for 6-month mortality within a population of oldest old HF patients. Materials and methods: Observational cohort study with 6-month follow-up considering 171 subjects aged 85-89 years and 104 aged ≥90 years, consecutively admitted from March 2007 to August 2012 within the Orthogeriatric Unit (OGU) of an Italian teaching hospital. We collected demographic characteristics, comorbidities, medications, functional-cognitive-nutritional status, type of fracture and intervention. Considered outcomes included postoperative complications, re-hospitalisations, and survival. We finally analyzed the potential risk factors of 6-month mortality with multivariable logistic regression models to identify the independent predictors. Results: Nonagenarians were significantly more dependent in Katz’s ADL (p=.024) and impaired in MMSE scores (p=.008) than their counterparts. No differences were observed among the other characteristics. Considering the outcomes, nonagenarians showed the highest in-hospital and 6-month mortality rates. The analysis of the potential risk factors for 6-month mortality performed on the whole sample enlightened a role of independent predictors for delirium and pre-fracture severe disability (0-2 spared ADL), but not for age. Conclusion: Severe disability and incident delirium have a strong impact on 6-month mortality, but only delirium is potentially preventable. A careful assessment and early correction of its modifiable predisposing and precipitating factors is the main strategy we suggest to reduce the mortality risk among the oldest old.