Not all placebos are equal

NOT all placebos are equal, research demonstrates.

A systematic review and network meta-analysis of 149 randomised trials of adults reporting knee osteoarthritis pain showed that intra-articular and topical placebo had a significantly greater effect than oral placebo.

These effect sizes increased alongside a rise in baseline pain scores.

US researchers also found that ignoring the response to the type of placebo substantially altered the relative efficacies of the active treatments.

Different placebos can exert clinically relevant effects and