Reducing hip fracture risk with risedronate in elderly women with established osteoporosis

BACKGROUND There is limited evidence to support the efficacy of current pharmaceutical agents in reducing the risk of hip fracture in older postmenopausal women with established osteoporosis. OBJECTIVE To clarify the efficacy of risedronate in reducing the risk of hip fracture in elderly postmenopausal women aged > or = 70 years with established osteoporosis, i.e., those with bone mineral density-defined osteoporosis and a prevalent vertebral fracture. METHODS Post hoc analysis of the Hip Intervention Program (HIP) study, a randomized controlled trial comparing risedronate with placebo for reducing the risk of hip fracture in elderly women. Women aged 70 to 100 years with established osteoporosis (baseline femoral neck T-score < or = -2.5 and > or =1 prior vertebral fracture) were included. The main outcome measure was 3-year hip fracture incidence in the risedronate and placebo groups. RESULTS A total of 1656 women met the inclusion criteria. After 3 years, hip fracture had occurred in 3.8% of risedronate-treated patients and 7.4% of placebo-treated patients (relative risk 0.54; 95% confidence interval 0.32-0.91; P = 0.019). CONCLUSION Risedronate significantly reduced the risk of hip fracture in women aged up to 100 years with established osteoporosis.