Mortality Risk After Hip Fracture

Abstract

Objective To determine the mortality risk following hip fracture and identify factors predictive of increased mortality. Design Retrospective review of prospectively collected data. Setting Tertiary care orthopaedic hospital. Background Approximately 250,000 hip fractures occur annually in the United States. The greatest mortality risk following hip fracture has been demonstrated to be within the first 6 months of fracture, and some studies report that the risk approaches expected mortality after 6 months. However, more recent studies have demonstrated that an increased risk of mortality may persist for several years postfracture. The purpose of this study was to assess the excess mortality associated with hip fracture at up to 2 years postinjury. Methods All patients with a hip fracture who were admitted to our institution over a 10-year period were evaluated. Criteria for inclusion included: Caucasian, age 65 or older, previously ambulatory, and home dwelling. Patients were followed prospectively to determine the mortality risk associated with hip fracture over a 2-year follow-up period. Mortality was compared to a standardized population and standardized mortality ratios were calculated. Results Eight hundred thirty-six patients met the inclusion criteria and were included. The mortality risk was highest within the first 3 months following fracture, with standardized mortality ratios approaching that of the control population by two years. Patients age 65–84 had higher mortality risk when compared with patients age ≥85. American Society of Anesthesiologists classification was predictive of increased mortality risk in younger patients, with these patients having triple the mortality risk when compared to the reference population at 2-year follow-up. More elderly patients had minimal excess mortality associated with hip fracture at 1- and 2-year follow-up, regardless of ASA classification. Conclusion The data demonstrate that hip fracture is not associated with significant excess mortality amongst patients older than age 85. Amongst younger patients, however, those with ASA classifications of 3 or 4 have significant excess mortality following hip fracture that persists up to 2 years after injury.