Comorbidity and mortality following hip fracture: a population-based cohort study

Abstract

Background and aims: Identifying predictors for mortality following hip fracture is essential in order to improve survival, especially among the elderly. We compared mortality after hip fracture to controls without hip fracture, and assessed the impact of comorbidity on mortality following hip fracture in a population-based cohort study.

Methods: The health care databases in Western Denmark (1.4 million inhabitants) were used to identify all persons > or = 40 years of age with first-time hospitalization for hip fracture between 1/1/1998 and 1/31/2003. Five population controls without hip fracture were matched to hip fracture patients on age and gender. Prior hospitalization for selected comorbidities among hip fracture subjects was assessed from hospital discharge registries. Cox regression analysis was used to compute crude and adjusted relative risks and 95% confidence intervals for 30-day, 90-day, and 1-year mortality associated with hip fracture, and with prior hospital history of selected comorbidities.

Results: The cohort was followed for an average of 22 months. Females comprised 71% of the cohort and 90% was aged 65 years or older. Compared to persons without hip fracture, persons with hip fracture had from 2 to >3-fold higher risk of death at 1 year. History of congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), dementia, tumor, and malignancy increased adjusted 1-year mortality from 50% to 3-fold among persons with hip fracture.

Conclusions: Hip fracture increased 1-year mortality more than 3-fold compared with mortality without hip fracture. Among hip fracture subjects, the presence of selected comorbidities further increased the risk of mortality after hip fracture.