Certainty of genuine treatment increases drug responses among intellectually disabled patients
Open/View files
Date
2017
Author(s)
Jensen, Karin B.
Pontén, Moa
Rosén, Annelie
Yang, Kathy
des Portes, Vincent
Curie, Aurore
Publisher
Lippincott Williams & Wilkins
The Harvard community has made this article openly available. Please share how this access benefits you.
Citation
Jensen, Karin B., Irving Kirsch, Moa Pontén, Annelie Rosén, Kathy Yang, Randy L. Gollub, Vincent des Portes, Ted J. Kaptchuk, and Aurore Curie. 2017. “Certainty of genuine treatment increases drug responses among intellectually disabled patients.” Neurology 88 (20): 1912-1918. doi:10.1212/WNL.0000000000003934. http://dx.doi.org/10.1212/WNL.0000000000003934.
Abstract
Objective: To determine the placebo component of treatment responses in patients with intellectual disability (ID). Methods: A statistical meta-analysis comparing bias-corrected effect sizes (Hedges g) of drug responses in open-label vs placebo-controlled clinical trials was performed, as these trial types represent different certainty of receiving genuine treatment (100% vs 50%). Studies in fragile X, Down, Prader-Willi, and Williams syndrome published before June 2015 were considered. Results: Seventeen open-label trials (n = 261, 65% male; mean age 23.6 years; mean trial duration 38 weeks) and 22 placebo-controlled trials (n = 721, 62% male; mean age 17.1 years; mean trial duration 35 weeks) were included. The overall effect size from pre to post treatment in open-label studies was g = 0.602 (p = 0.001). The effect of trial type was statistically significant (p = 0.001), and revealed higher effect sizes in studies with 100% likelihood of getting active drug, compared to both the drug and placebo arm of placebo-controlled trials. We thus provide evidence for genuine placebo effects, not explainable by natural history or regression toward the mean, among patients with ID. Conclusions: Our data suggest that clinical trials in patients with severe cognitive deficits are influenced by the certainty of receiving genuine medication, and open-label design should thus not be used to evaluate the effect of pharmacologic treatments in ID, as the results will be biased by an enhanced placebo component.
Other Available Sources
Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material (LAA), as set forth at Terms of Service
Collection