Increased mortality in patients with a hip fracture-effect of pre-morbid conditions and post-fracture complications

Abstract

In a cohort of 169,145 patients with a hip fracture and 524,010 controls we observed an excess mortality among patients compared to controls for as long as 20 years after the hip fracture. The main reason for the excess mortality was linked to the trauma that caused the hip fracture.

Introduction: Patients with a hip fracture have a significant excess mortality. However, it remains unclear if the mortality is linked to the pre-morbid conditions or to complications to the fracture.

Methods: All subjects with a hip fracture in Denmark between 1977 and 2001 were compared with three age- and gender-matched subjects from the general population.

Results: A total of 169,145 fracture cases were compared to 524,010 controls. The cases had a much higher prevalence of co-morbidity than the controls. The mortality rate was twice as high in fracture cases compared with controls (HR = 2.26, 95% CI: 2.24-2.27). Adjustments for confounders only changed the excess mortality risk little. The mortality after the hip fracture was divided into two categories: an excess mortality of 19% within the first year following the fracture (relative survival = 0.81 compared to controls), and an excess mortality of 1.8% per year (relative survival 0.982) for every additional year following the fracture. The major causes of the excess mortality were due to complications to the fracture event (70.8% within the first 30 days).

Conclusions: Patients with a hip fracture have a pronounced excess mortality risk. The major cause was linked to the fracture event and not to pre-existing co-morbidity.