RESUMEN
BACKGROUND: Several studies have used placebo acupuncture methods in recent years as a way for blinding therapeutic effect of acupuncture, however placebo method selection has not followed enough methodological criteria to the point of stabilishing a consensus of what should be the best method to be used. This study aimed to evaluate the effectiveness of three different placebo acupuncture methods for blinding applied in healthy subjects. METHODS: This study was approved by the Ethics Committee of the Federal University of Sergipe with the number 47193015.5.0000.5546 and all individuals participating in the study signed a free and informed consent. For this study, 321 healthy volunteers were randomly divided into seven groups using the abdominal point stomach (ST) 25 and seven groups using the lumbar point bladder (Bl) 52 for stimulation. For real acupuncture procedure, three different methods of placebo acupuncture plus a mix between real acupuncture and placebo applied in the same individual, totaling fourteen groups in this study. Outcome assessments were performed before and immediately after applying the technique. Investigator who assessed variables had no knowledgement about the method was applied. Identification, weight and height were measured before puncture by using. At the end, subjects were asked if they believed they were receiving real or placebo acupuncture. RESULTS: There was no significant difference between groups for the perception about the type o stimulation (wheter real or placebo puncture). Percentage of subjects who reported to have received real acupuncture in the abdominal point was 69.56% in real group, 86.95% in group Park Sham, 82.60% in needle + foam, 91.30% in insertion and removal, 78.26% in real + Park Sham, 86.36% in real + needle and foam, 86.95% in real + insertion and removal, and for the lumbar point was 86.36% in real group, 86.95% in group Park Sham, 69.56% in needle + foam, 72% in insertion and removal, 86.95% in real + Park Sham, 81.81% in real + needle and foam and 78.26% in real + insertion and removal. CONCLUSION: All placebo acupuncture methods proposed in this study were equally effective for bliding the study participants using either abdominal or lumbar acupoints, and none of the placebo methods presented benefit compared to the other to be used in future clinical trials. ETHICS COMMITTEE: Federal University of Sergipe (UFS), number of approval: 47193015.5.0000.5546 TRIAL REGISTRATION: ensaiosclinicos.gov.br RBR-3w2p32 Registered in 28th January 2016.