Dataset Information

Predictors of placebo response in pharmacological and dietary supplement treatment trials in pediatric autism spectrum disorder: a meta-analysis.

ABSTRACT: Large placebo responses in many clinical trials limit our capacity to identify effective therapeutics. Although it is often assumed that core behaviors in children with autism spectrum disorders (ASDs) rarely remit spontaneously, there has been limited investigation of the size of the placebo response in relevant clinical trials. These trials also rely on caregiver and clinical observer reports as outcome measures. The objectives of this meta-analysis are to identify the pooled placebo response and the predictors of placebo response in pharmacological and dietary supplement treatment trials for participants with a diagnosis of ASD. Randomized controlled trials (RCTs) in pediatric ASD, conducted between 1980 and August 2014, were identified through a search of Medline, EMBASE, Web of Science, Cochrane Database of Systematic Reviews and clinicaltrials.gov. RCTs of at least 14 days duration, comparing the treatment response for an oral active agent and placebo using at least one of the common outcome measures, were included. Analysis of 25 data sets (1315 participants) revealed a moderate effect size for overall placebo response (Hedges' g=0.45, 95% confidence interval (0.34-0.56), P<0.001). Five factors were associated with an increase in response to placebo, namely: an increased response to the active intervention; outcome ratings by clinicians (as compared with caregivers); trials of pharmacological and adjunctive interventions; and trials located in Iran. There is a clear need for the identification of objective measures of change in clinical trials for ASD, such as evaluation of biological activity or markers, and for consideration of how best to deal with placebo response effects in trial design and analyses.

SUBMITTER: Masi A

PROVIDER: S-EPMC5068810 | biostudies-other | 2015 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Predictors of placebo response in pharmacological and dietary supplement treatment trials in pediatric autism spectrum disorder: a meta-analysis.

Masi A A Lampit A A Glozier N N Hickie I B IB Guastella A J AJ

Translational psychiatry 20150922

Large placebo responses in many clinical trials limit our capacity to identify effective therapeutics. Although it is often assumed that core behaviors in children with autism spectrum disorders (ASDs) rarely remit spontaneously, there has been limited investigation of the size of the placebo response in relevant clinical trials. These trials also rely on caregiver and clinical observer reports as outcome measures. The objectives of this meta-analysis are to identify the pooled placebo response ...[more]

PMID: 26393486

Similar Datasets

Project description:BACKGROUND:Placebo response in autism spectrum disorder (ASD) might dilute drug-placebo differences and hinder drug development. Therefore, this meta-analysis investigated placebo response in core symptoms. METHODS:We searched ClinicalTrials.gov , CENTRAL, EMBASE, MEDLINE, PsycINFO, WHO-ICTRP (up to July 8, 2018), and PubMed (up to July 4, 2019) for randomized pharmacological and dietary supplement placebo-controlled trials (RCTs) with a minimum of seven days of treatment. Single-group meta-analyses were conducted using a random-effects model. Standardized mean changes (SMC) of core symptoms in placebo arms were the primary outcomes and placebo positive response rates were a secondary outcome. Predictors of placebo response were investigated with meta-regression analyses. The protocol was registered with PROSPERO ID CRD42019125317 . RESULTS:Eighty-six RCTs with 2360 participants on placebo were included in our analysis (87% in children/adolescents). The majority of trials were small, single-center with a duration of 8-12 weeks and published after 2009. Placebo response in social-communication difficulties was SMC = -?0.32, 95% CI [-?0.39, -?0.25], in repetitive behaviors -?0.23[-?0.32, -?0.15] and in scales measuring overall core symptoms -?0.36 [-?0.46, -?0.26]. Overall, 19%, 95% CI [16-22%] of participants were at least much improved with placebo. Caregiver (vs. clinician) ratings, lower risk of bias, flexible-dosing, larger sample sizes and number of sites, less recent publication year, baseline levels of irritability, and the use of a threshold of core symptoms at inclusion were associated with larger placebo response in at least a core symptom domain. LIMITATIONS:About 40% of the trials had an apparent focus on core symptoms. Investigation of the differential impact of predictors on placebo and drug response was impeded by the use of diverse experimental interventions with essentially different mechanisms of action. An individual-participant-data meta-analysis could allow for a more fine-grained analysis and provide more informative answers. CONCLUSIONS:Placebo response in ASD was substantial and predicted by design- and participant-related factors, which could inform the design of future trials in order to improve the detection of efficacy in core symptoms. Potential solutions could be the minimization and careful selection of study sites as well as rigorous participant enrollment and the use of measurements of change not solely dependent on caregivers.

Dataset Information

Predictors of placebo response in pharmacological and dietary supplement treatment trials in pediatric autism spectrum disorder: a meta-analysis.

Publications

Predictors of placebo response in pharmacological and dietary supplement treatment trials in pediatric autism spectrum disorder: a meta-analysis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets