A meta-analysis of etidronate for the treatment of postmenopausal osteoporosis

The aim of the study was to review the effect of etidronate on bone density and fractures in postmenopausal women. We searched MEDLINE from 1966 to 19 98, examined citations of relevant articles, and the proceedings of interna tional osteoporosis meetings. We contacted osteoporosis investigators to id entify additional studies, primary authors, and pharmaceutical industry sou rces for unpublished data. We included 13 trials that randomized women to e tidronate or an alternative (placebo or calcium and/or vitamin D) and measu red bone density for at least I year. For each trial, three independent rev iewers assessed the methodologic quality and abstracted data. The data sugg ested a reduction in vertebral fractures with a pooled relative risk of 0.6 3 (95% CI 0.44 to 0.92). There was no effect on nonvertebral fractures (rel ative risk 0.99, (95% CI 0.69 to 1.42). Etidronate, relative to control, in creased bone density after 1-3 years of treatment in the lumbar spine by 4. 06% (95% CI 3.12 to 5.00), in the femoral neck by 2.35% (95% CI 1.66 to 3.0 4) and in the total body by 0.97% (95% CI 0.39 to 1.55), Effects were large r at 4 years, though the number of patients followed much smaller. Etidrona te increases bone density in the lumbar spine and femoral neck for up to 4 years. The pooled estimates of fracture reduction with etidronate suggest a reduction in vertebral fractures, but no effect on nonvertebral fractures.