Dramatic trial results are often too good to be true

JAMA2012;308:1676-84OpenUrlCrossRefPubMedWeb of Science

New interventions rarely make large differences to patient outcomes when tested in trials. Trials that report very large effects (odds ratios ≥5 or ≤0.2) are usually small and investigate surrogate outcomes, such as laboratory test results, rather than clinical outcomes, such as death, say researchers. In …