This study explored participants' experiences of randomized controlled trial (RCT) participation to examine their understanding of the trial design and whether their consent was indeed informed. A nested qualitative interview study was conducted with 38 participants from a sample of 282 who participated in a complex RCT evaluating the effectiveness of laser compared with needle acupuncture for chronic knee pain. Overall participants had a good understanding of the RCT, and concepts such as randomization and placebo. Their experiences of being in the trial were largely positive, even if they did not experience any knee pain improvement. Their responses to unblinding at the end of the study were accepting. Participants had a good functional understanding of the RCT, sufficient for valid informed consent.
Keywords: RCT; informed consent; participants’ experience; participants’ understanding.
© The Author(s) 2015.