Abstract
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.