title: Is the perceived placebo effect comparable between adults and children? A meta-regression analysis.
abstract: A potential larger perceived placebo effect in children compared with adults could influence the detection of the treatment effect and the extrapolation of the treatment benefit from adults to children. This study aims to explore this potential difference, using a meta-epidemiological approach.
  
  
  
  A systematic review of the literature was done to identify trials included in meta-analyses evaluating a drug intervention with separate data for adults and children. The standardized mean change and the proportion of responders (binary outcomes) were used to calculate the perceived placebo effect. A meta-regression analysis was conducted to test for the difference between adults and children of the perceived placebo effect.
  
  
  
  For binary outcomes, the perceived placebo effect was significantly more favorable in children compared with adults (β = 0.13; P = 0.001). Parallel group trials (β = -1.83; P < 0.001), subjective outcomes (β = -0.76; P < 0.001), and the disease type significantly influenced the perceived placebo effect.
  
  
  
  The perceived placebo effect is different between adults and children for binary outcomes. This difference seems to be influenced by the design, the disease, and outcomes. Calibration of new studies for children should consider cautiously the placebo effect in children.
authors.affiliation: UMR 5558, CNRS, Claude Bernard University Lyon 1, Lyon, France.
authors.forename: Perrine
authors.initials: P
authors.lastname: Janiaud
authors.affiliation: UMR 5558, CNRS, Claude Bernard University Lyon 1, Lyon, France.|Department of Clinical Pharmacology, CHU Lyon, Lyon, France.|EPICIME-Clinical Investigation Center, INSERM CIC1407/UMR5558, Bron, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Cornu
authors.affiliation: UMR 5558, CNRS, Claude Bernard University Lyon 1, Lyon, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Lajoinie
authors.affiliation: UMR 5558, CNRS, Claude Bernard University Lyon 1, Lyon, France.
authors.forename: Amina
authors.initials: A
authors.lastname: Djemli
authors.affiliation: Department of Clinical Pharmacology, CHU Lyon, Lyon, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Cucherat
authors.affiliation: UMR 5558, CNRS, Claude Bernard University Lyon 1, Lyon, France.|Department of Clinical Pharmacology, CHU Lyon, Lyon, France.|EPICIME-Clinical Investigation Center, INSERM CIC1407/UMR5558, Bron, France.
authors.forename: Behrouz
authors.initials: B
authors.lastname: Kassai
mesh_terms: D000328:Adult; D000367:Age Factors; D002648:Child; D006801:Humans; D010465:Perception; D015990:Placebo Effect; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D012044:Regression Analysis