Meta-analyses of therapies for postmenopausal osteoporosis. IV. Meta-analysis of raloxifene for the prevention and treatment of postmenopausal osteoporosis

Abstract

Objective: To review the effect of raloxifene on bone density and fractures in postmenopausal women.

Data source: We searched MEDLINE from 1966 to 2000 and examined citations of relevant articles and the proceedings of international osteoporosis meetings.

Study selection: We included seven trials that randomized women to raloxifene or placebo, with both groups receiving similar calcium and vitamin D supplementation, and measured bone density for at least one year.

Data extraction: For each trial, three independent reviewers abstracted the data and assessed the methodological quality using a validated tool.

Data synthesis: Data from one large dominating trial suggest a reduction in vertebral fractures with a relative risk (RR) of 0.60 [95% confidence interval (CI) 0.50-0.70, P < 0.01]. The RR of nonvertebral fractures in patients given 60 mg or more of raloxifene in the larger study was 0.92 (95% CI 0.79-1.07, P = 0.27). Raloxifene resulted in positive effects on the percentage change in bone density, which increased over time and was independent of dose. At the final year, point estimates and 95% CIs for the differences in percent change in bone density (95% CI) between raloxifene and placebo groups were 1.33 (95% CI 0.37-2.30) for total body, 2.51 (95% CI 2.21-2.82) for lumbar spine, 2.05 (95% CI 0.71-3.39) for combined forearm, and 2.11 (95% CI 1.68-2.53) for combined hip (P < 0.01 at all four sites). Results were similar across studies, and formal tests of heterogeneity did not approach conventional statistical significance. Raloxifene slightly increased rates of withdrawal from therapy as a result of adverse effects (RR 1.15, 95% CI 1.00-1.33, P = 0.05). The pooled RR was significant for hot flashes 1.46 (95% CI 1.23-1.74, P < 0.01) and nonsignificant for leg cramps 1.64 (95% CI 0.84-3.20, P = 0.15).

Conclusion: Raloxifene increases bone density, and the effect increases over 2 yr. The data suggest a positive impact of raloxifene on vertebral fractures. There was little effect of raloxifene on nonvertebral fractures.