This report summarizes the meta-analyses and subsequent
randomized trials that have evaluated the effect of
various agents on the risk for osteoporotic fractures. These
analyses support a role for many of these agents in reducing
the risk for fracture compared with placebo. We did not
identify any studies that demonstrated superiority of 1
agent over another in preventing fractures. However, no
trial with head-to-head comparisons of 2 or more agents
enrolled sufficient sample sizes to detect even large differences
in risk.