Comparing two treatments using separate pooled estimates rather than a head-to-head trial.
An indirect comparison contrasts outcomes pooled from one set of studies of treatment A against outcomes pooled from a separate set of studies of treatment B, without a direct within-study comparator. It is weaker evidence than a direct comparative study because differences in populations and surveillance between the two source literatures can masquerade as a treatment effect.
This guide was auto-drafted and is pending editorial review.