Putting evidence-based medicine into clinical practice: comparing anti-resorptive agents for the treatment of osteoporosis

Objective: To compare the effectiveness of anti-resorptive agents in reducing the risk of vertebral and non-vertebral fractures using data from published meta-analyses and the technique of adjusted indirect comparisons. Research design and methods: Pairs of agents were compared by adjusted indirect comparison of their effects relative to a common comparator (placebo) using meta-analyses published by The Osteoporosis Methodology Group and The Osteoporosis Research Advisory Group. Results: Adjusted indirect comparisons identified only one pair of agents that had significantly different effects on vertebral fracture incidence: alendronate was 34% more effective than calcitonin (Relative Risk: 0.66, 95% Confidence Interval: 0.48-0.90). Alendronate was significantly more effective than risedronate, calcitonin, estrogen, etidronate, and raloxifene (Relative Risks: 0.70 [0.49, 0.99], 0.64 [0.42, 0.98], 0.59 [0.41, 0.84], 0.52 [0.32, 0.82], and 0.56 [0.40, 0.78], respectively) in reducing the incidence of non-vertebral fractures. No other significant pairwise differences were observed. Conclusions: The results suggest that there are differences in anti-fracture efficacy among anti-resorptive agents, particularly for non-vertebral fractures. Direct head-to-head comparisons would be needed to confirm these findings but are unlikely to be conducted.