Does random participant assignment cause fewer benefits in research participants? Systematic review of partially randomized acupuncture trials.

It has been suggested that the random assignment of participants does not cause harm to patients in clinical trials. However, in a recent study, patient preference affected the health outcome of the patients. It can therefore be assumed that patients who are allocated at random may be affected by placebo effects that are associated with the treatment of their choice. The aim of this study was to determine whether random participant assignment in acupuncture trials causes fewer benefits to the participants.