Open-label placebo vs double-blind placebo for irritable bowel syndrome: a randomized clinical trial. Issue 9 (September 2021)

• Record Type: Journal Article
• Authors: Lembo, Anthony; Kelley, John M.; Nee, Judy; Ballou, Sarah; Iturrino, Johanna; Cheng, Vivian; Rangan, Vikram; Katon, Jesse; Hirsch, William; Kirsch, Irving; Hall, Kathryn; Davis, Roger B.; Kaptchuk, Ted J.
• Is Part Of: Pain. Volume 162:Issue 9(2021)
• Publication Date: 2021-09
• Subjects: Irritable bowel syndrome -- Placebo -- Chronic abdominal pain; Pain -- Periodicals; Douleur -- Périodiques; Anesthésie -- Périodiques; Pain; Electronic journals; Periodicals; Electronic journals; 616.0472
• DOI: 10.1097/j.pain.0000000000002234
• Languages: English
• ISSNs: 0304-3959

Abstract

Abstract : Abstract: It is commonly believed that blinding to treatment assignment is necessary for placebos to have an effect. However, placebos administered without concealment (ie, open-label placebos [OLPs]) have recently been shown to be effective in some conditions. This study had 2 objectives: first, to determine whether OLP treatment is superior to no-pill control (NPC) in irritable bowel syndrome (IBS) and, second, to compare the efficacy of OLP against double-blind placebo (DBP). In a 6-week, 3-arm, randomized clinical trial, participants were randomized in equal proportions to 3 arms: OLP, DBP, or NPC. Two hundred sixty-two adults (72.9% women), with a mean age of 42.0 (SD = 18.1) years, participated in the primary study. The mean improvement on the IBS Severity Scoring System from baseline to the 6-week end point was significantly greater in OLP compared with that in NPC (90.6 vs 52.3, P = 0.038). Open-label placebo and DBP did not differ significantly on IBS Severity Scoring System improvement (100.3 vs 90.6, P = 0.485). Standardized effect sizes were moderate for OLP vs NPC (d = 0.43) and small for OLP vs DBP (d = 0.10). Participants treated with OLP reported clinically meaningful improvements in IBS symptoms that were significantly greater than those on NPC. Open-label placebo and DBP had similar effects that did not differ significantly, suggesting that blinding may not be necessary for placebos to be effective and that OLP could play a role in the management of patients with refractory IBS. Abstract : Supplemental Digital Content is Available in the Text.In this 6-week, 3-armed, randomized clinical trial that included 262 adults with irritable bowel syndrome, symptom improvement with open-label placebo was significantly greater than that with no-pill control; however, open-label placebo and double-blind placebo did not differ significantly. Our results suggest that blinding may not be necessary for placebo to be effective and that open-label treatment could have a role in the management of patients with refractory irritable bowel syndrome.