Participants' experiences of being debriefed to placebo allocation in a clinical trial

Participants in placebo-controlled clinical trials give informed consent to be randomized to verum or placebo. However, researchers rarely tell participants which treatment they actually received. We interviewed 4 participants in a trial of acupuncture for irritable bowel syndrome before, during, and after they received a course of placebo treatments over 6 weeks. During the final interview, we informed participants that they had received a course of placebo treatments. We used an idiographic phenomenological approach based on the Sheffield School to describe each participant's experiences of being blinded to and then debriefed to placebo allocation. The participants' experiences of blinding and debriefing were embodied, related to their goals in undertaking the study, and social (e.g., embedded in trusting and valued relationships with acupuncturists). We suggest ways in which debriefing to placebo allocation can be managed sensitively to facilitate positive outcomes for participants.