Hip Fracture and Short- and Long-Term Mortality Risk

Nearly 300,000 hip fractures occur in the United States each year, causing substantial short- and long-term disability and increased mortality.

According to a recent meta-analysis, women had nearly 3-fold increased mortality risk in the year following hip fracture. In that analysis, increased risk of mortality from hip fracture decreased during the first 2 years following the fracture but it did not return to the rate of age-matched control participants during a 10-year follow-up. According to researchers, limitations to previous studies designed to determine mortality risk have made it difficult to determine whether the increase in mortality following hip fracture is the result of the fracture itself or underlying poor health.

Some studies have resulted in conflicting results, some finding that healthy participants with no comorbidities do not have increased risk of mortality after hip fracture. Others have found higher mortality in participants with no comorbidities compared with those with comorbidities. Studies to determine the association of age with mortality after hip fracture have also demonstrated conflicting results. Some studies found that mortality after hip fracture increases with age, whereas in several studies in Europe, the relative risk of death after hip fracture compared with the risk of death in the general population was lower in older versus younger patients with hip fractures.

Researchers recently conducted a study to determine the short-term (≤1 year), intermediate-term (>1 to ≤5 years), and long-term (>5 years) mortality associated with hip fracture. The study’s secondary aim was to determine whether healthy women >80 years of age would have increased mortality associated with hip fracture compared with healthy age-matched patients. They reported results in Archives of Internal Medicine [2011;171(20):1831-1837]. The study involved 5580 women from a large community-based multicenter US prospective cohort who were observed for nearly 20 years. Of the 5580 participants, 1116 were incident hip fracture cases and 4464 were in the age-matched nonfracture control group.

Compared with the control group, the patients in the hip fracture group had lower body mass index, lower total hip bone mineral density (BMD), and more cigarette exposure. A slightly higher proportion of hip fracture cases had Parkinson disease and needed to use their arms to stand from a chair. Among those <70 years of age (but not in the older age groups), more cases than controls had diabetes mellitus (P=.002). In those ≥80 years of age, self-reported health was worse in the hip fracture group compared with the nonfracture controls (P=.04). In the year following fracture, those with hip fracture had a 2-fold increased mortality compared with controls (16.9% [n=189] vs 8.4% [n=374]; odds ratio [OR], 2.3; 95% confidence interval [CI], 1.9-2.8).

When the analysis was adjusted for other risk fractures for hip fracture, including total hip BMD, the increase in mortality persisted (multivariate OR, 2.4; 95% CI, 1.9-3.1). When examined by age and health status, the risk of death from hip fracture decreased as age increased. Short-term mortality was increased compared with controls in participants aged 65 to 69 years (16.3% vs 3.7%; OR, 5.0; 95% CI, 2.6-9.5). There was no increase in risk of death in the first year following a hip fracture in those ≥80 years of age (20.3% vs 16.8%; OR, 1.1; 95% CI, 0.6-2.1). During long-term follow-up, women aged 65 to 69 years had an increased risk of mortality compared with controls following hip fracture during postfracture years 1 through 5 (17.2% vs 11.3%; OR, 1.9; 95% CI, 1.1-3.2) and after year 5 through year 10 (12.1% vs 5.9%; OR, 3.2; 95% CI, 1.0-10.2). There was no increase in risk of death during long-term follow-up in the older age groups. In summary, the researchers said, “Short-term mortality is increased after hip fracture in women aged 65 to 79 years and in exceptionally healthy women ≤80 years of age. Women ≤70 years of age return to previous risk levels after a year. Interventions are needed to decrease mortality in the year after hip fracture, when mortality risk is highest.”