title: Validation of Placebo in a Manual Therapy Randomized Controlled Trial.
abstract: At present, no consensus exists among clinical and academic experts regarding an appropriate placebo for randomized controlled trials (RCTs) of spinal manipulative therapy (SMT). Therefore, we investigated whether it was possible to conduct a chiropractic manual-therapy RCT with placebo. Seventy migraineurs were randomized to a single-blinded placebo-controlled clinical trial that consisted of 12 treatment sessions over 3 months. The participants were randomized to chiropractic SMT or placebo (sham manipulation). After each session, the participants were surveyed on whether they thought they had undergone active treatment ("yes" or "no") and how strongly they believed that active treatment was received (numeric rating scale 0-10). The outcome measures included the rate of successful blinding and the certitude of the participants' beliefs in both treatment groups. At each treatment session, more than 80% of the participants believed that they had undergone active treatment, regardless of group allocation. The odds ratio for believing that active treatment was received was >10 for all treatment sessions in both groups (all p < 0.001). The blinding was maintained throughout the RCT. Our results strongly demonstrate that it is possible to conduct a single-blinded manual-therapy RCT with placebo and to maintain the blinding throughout 12 treatment sessions given over 3 months.
authors.affiliation: 1] Head and Neck Research Group, Research Centre, Akershus University Hospital, 1478 Lørenskog, Oslo, Norway [2] Institute of Clinical Medicine, Akershus University Hospital, University of Oslo, 1474 Nordbyhagen, Oslo, Norway.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Chaibi
authors.affiliation: 1] Institute of Clinical Medicine, Akershus University Hospital, University of Oslo, 1474 Nordbyhagen, Oslo, Norway [2] HØKH, Research Centre, Akershus University Hospital, 1478 Lørenskog, Oslo, Norway.
authors.forename: Jūratė
authors.initials: J
authors.lastname: Šaltytė Benth
authors.affiliation: 1] Head and Neck Research Group, Research Centre, Akershus University Hospital, 1478 Lørenskog, Oslo, Norway [2] Institute of Clinical Medicine, Akershus University Hospital, University of Oslo, 1474 Nordbyhagen, Oslo, Norway.
authors.forename: Michael
authors.initials: M
authors.lastname: Bjørn Russell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D020773:Headache Disorders / Q000628:therapy; D006801:Humans; D008297:Male; D026882:Manipulation, Chiropractic; D008875:Middle Aged; D026201:Musculoskeletal Manipulations; D016017:Odds Ratio; D015990:Placebo Effect; D016896:Treatment Outcome; D054928:Validation Studies as Topic; D055815:Young Adult