Osteoporosis associated with significant five-year risk of hip fracture in women 80 years and older

Women with osteoporosis had similar mortality risk, but much higher rates of hip fracture, compared to those without osteoporosis but with other risk factors for fracture.

In five years of follow-up, 13% of women 80 years and older with osteoporosis had a hip fracture, and rates were even higher in those with more comorbidities, a prospective cohort study found.

To determine the association of comorbidities and prognosis with five-year hip fracture risk in women 80 years of age or older, researchers conducted a prospective cohort study of 1,528 community-dwelling women identified as potential candidates for osteoporosis drug treatment at four sites between March 2018 and January 2019. Five-year hip fracture probability was calculated accounting for competing mortality risk. Results were published June 17 by JAMA Internal Medicine.

Participants were classified into two groups, those with osteoporosis (n=761) and those without osteoporosis but at high fracture risk (n=767). Overall, 125 (8.0%) women had a hip fracture and 287 (18.8%) died without having one. Five-year hip fracture rate was 13.0% (95% CI, 10.7% to 15.5%) among women with osteoporosis and 4.0% (95% CI, 2.8% to 5.6%) in the high-fracture risk group. Five-year mortality was 24.9% (95% CI, 21.8% to 28.1%) among women with osteoporosis and 19.4% (95% CI, 16.6% to 22.3%) among women without osteoporosis but at high fracture risk.

In both groups, the probability of death increased with more comorbidities and poorer prognosis. Associations between comorbidities and hip fracture were much stronger in the osteoporosis group. For example, among women with three or more comorbid conditions, hip fracture probability was 18.1% (95% CI, 12.3% to 24.9%) among women with osteoporosis versus 2.5% (95% CI, 1.3% to 4.2%) among women without osteoporosis but at high fracture risk.

The authors noted that the results support drug treatment to prevent hip fractures in older women with osteoporosis, particularly those with comorbidities. “If drug therapy is equally effective in women 80 years and older as in postmenopausal women younger than 80 years, these results suggest that the absolute benefit of treatment in preventing hip fracture in late-life women may be greatest among those women with osteoporosis and substantial comorbidity burden or limited life expectancy, because these characteristics, while predictive of mortality, are also strongly associated with hip fracture risk,” the authors concluded.