Meta-analysis about efficacy of anti-resorptive drugs in post-menopausal osteoporosis

Objective: The purpose of this study was to compare the effect of three groups of anti-resorptive drugs in post-menopausal osteoporosis. Data sources: We collected data covering the period between 1983 and 1995, by first using MEDLINE. References retrieved were scanned further to identify additional papers. Study selection: Only randomized studies evaluating bone mass by means of dual-photon or dual energy densitometry over a period of 1 year were accepted. Data extraction: Studies were arranged into three drug groups. We used densitometry results after 1 year in all treatment or control groups. Factors which might interfere with the results were recorded for subsequent separate analysis. Data synthesis: The MEDLINE search identified almost 25,000 studies. On reading the abstracts, 275 trials appeared to be controlled trials and original copies were retrieved for detailed analysis. A total of 31 articles which satisfied the inclusion criteria were identified. The first meta-analysis included studies which compared oestrogens and placebo, and the global effect-size was 0.54 (95% CI 0.34, 0.73). The second meta-analysis compared calcitonins with placebo and produced an effect-size of 0.41 (95% CI 0.21, 0.61) The third analysis compared bisphosphonates and placebo and showed an effect-size of 0.87 (95% CI 0.68, 1.07). Only oestrogen dose affected the results found. Conclusions: Bisphosphonates had the greatest effect on bone mass in post-menopausal osteoporosis.