Predictors of short- and long-term mortality in males and females with hip fracture - a prospective observational cohort study

Abstract

Background: Hip fracture is associated with increased mortality. Our aim was to study potential risk factors, including osteoporosis, associated with short- and long-term mortality in a prospectively recruited cohort of fragility hip fracture patients.

Methodology/principal findings: Fragility hip fracture patients aged >50 years admitted to a county hospital in Southern Norway in 2004 and 2005 were consecutively identified and invited for assessment. Patients with high energy or pathological fractures, patients with confusion, serious infections or who were non-residents in the catchment area were excluded. As part of a clinical routine, data were collected using questionnaires. Standardized bone density measurements of lumbar spine and hip were performed. Potential predictors of hip fracture mortality were tested using univariate and multivariate logistic regression analysis. A total of 432 hip fracture patients (129 males and 303 females) were prospectively identified. Among them 296 (85 males and 211 females) patients [mean age 80.7 (SD 9.1)] were assessed at the Osteoporosis center. Variables independently associated with short-term mortality (after 1 year) were in females older age [Odds Ratio (OR) 6.95] and in males older age (OR 5.74) and pulmonary disease (OR 3.20), whereas no associations were observed with mortality for 3 months after the fragility hip fracture. Variables independently associated with 5 years mortality in males was osteoporosis (OR 3.91) and older age (OR 6.95), and in females was dementia (OR 4.16) and older age (OR 2.80).

Conclusion: Apart from known predictors as age and comorbidity osteoporosis in our study was identified as a potential independent predictor of long-term hip fracture mortality in males. This is of particular importance as treatment with bisphosphonates after hip fracture has been shown to reduce hip fracture mortality and may be a clinical target to reduce the burden of the disease. Further studies however are needed to confirm the validity of this finding.

Figure 1. Kaplan-Meier survival curves of male and female hip fracture patients prospectively recruited into the prospective osteoporosis cohort compared to those excluded from the study.