Guided Imagery for Total Knee Replacement: Responses to an Audiobook Placebo Treatment

The use of a placebo is the gold standard for establishing the efficacy of new treatments in randomized controlled trials (RCTs). Placebo treatments are inert; this allows specific effects of the experimental treatment to be separated from nonspecific physiological, psychological, and social effects. The aim of this study was to scrutinize the workings of an audiobook (AB) placebo treatment, which was used in a placebo-controlled, investigator-blinded, RCT of the effect of guided imagery (GI) to improve pain and function in persons undergoing total knee replacement. A secondary analysis of quantitative and narrative data collected during the RCT was performed. The AB treatment provided attention control. Participants in the AB group identified benefits—pleasant get-away, new knowledge, quiet time-out, and inspiration; however, there was also evidence of resentful demoralization, especially in the postoperative period. The use of ABs as a placebo treatment in GI RCTs should be executed with caution.