Margrit Fässler1, Karin Meissner2, Jos Kleijnen3, Asbjørn Hróbjartsson4, Klaus Linde2. 1. Institute of General Practice, Klinikum rechts der Isar, Technische Universität München, Orleansstrasse 47, 81667 Munich, Germany. Electronic address: faessler@ethik.uzh.ch. 2. Institute of General Practice, Klinikum rechts der Isar, Technische Universität München, Orleansstrasse 47, 81667 Munich, Germany. 3. School for Public Health and Primary Care (CAPHRI), Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. 4. Nordic Cochrane Centre, Rigshospitalet, 7811, Blegdamsvej 9, 2100 Copenhagen, Denmark.
Abstract
OBJECTIVES: It has been suggested that some placebo interventions might be associated with larger clinical effects than others. In a systematic review, we investigated whether there is evidence from direct comparisons in randomized clinical trials including two or more placebo groups supporting this hypothesis. STUDY DESIGN AND SETTING: Eligible trials were identified through electronic database searches and citation tracking up to February 2013. Placebo interventions in a trial were categorized into a more intense and a less intense intervention based on complexity, invasiveness, or route of administration and time needed for application. RESULTS: Twelve studies with 1,059 patients receiving placebo met the eligibility criteria. Studies were highly heterogeneous regarding patients, interventions, outcomes, and risk of bias. Seven studies did not find any significant differences between the more intense and the less intense placebo intervention, four studies found differences for single outcomes, and one study consistently reported significantly larger effects of the more intense placebo. An explorative meta-analysis yielded a standardized mean difference -0.22 (95% confidence interval: -0.46, 0.02; P = 0.07; I(2) = 68%). CONCLUSION: In the studies included in this review, more intense placebos were not consistently associated with larger effects than less intense placebos.
OBJECTIVES: It has been suggested that some placebo interventions might be associated with larger clinical effects than others. In a systematic review, we investigated whether there is evidence from direct comparisons in randomized clinical trials including two or more placebo groups supporting this hypothesis. STUDY DESIGN AND SETTING: Eligible trials were identified through electronic database searches and citation tracking up to February 2013. Placebo interventions in a trial were categorized into a more intense and a less intense intervention based on complexity, invasiveness, or route of administration and time needed for application. RESULTS: Twelve studies with 1,059 patients receiving placebo met the eligibility criteria. Studies were highly heterogeneous regarding patients, interventions, outcomes, and risk of bias. Seven studies did not find any significant differences between the more intense and the less intense placebo intervention, four studies found differences for single outcomes, and one study consistently reported significantly larger effects of the more intense placebo. An explorative meta-analysis yielded a standardized mean difference -0.22 (95% confidence interval: -0.46, 0.02; P = 0.07; I(2) = 68%). CONCLUSION: In the studies included in this review, more intense placebos were not consistently associated with larger effects than less intense placebos.
Authors: Erlend Faltinsen; Adnan Todorovac; Laura Staxen Bruun; Asbjørn Hróbjartsson; Christian Gluud; Mickey T Kongerslev; Erik Simonsen; Ole Jakob Storebø Journal: Cochrane Database Syst Rev Date: 2022-04-04
Authors: K J Peerdeman; J Tekampe; A I M van Laarhoven; H van Middendorp; R C A Rippe; M L Peters; A W M Evers Journal: Eur J Pain Date: 2017-12-20 Impact factor: 3.931
Authors: Andrea W M Evers; Luana Colloca; Charlotte Blease; Marco Annoni; Lauren Y Atlas; Fabrizio Benedetti; Ulrike Bingel; Christian Büchel; Claudia Carvalho; Ben Colagiuri; Alia J Crum; Paul Enck; Jens Gaab; Andrew L Geers; Jeremy Howick; Karin B Jensen; Irving Kirsch; Karin Meissner; Vitaly Napadow; Kaya J Peerdeman; Amir Raz; Winfried Rief; Lene Vase; Tor D Wager; Bruce E Wampold; Katja Weimer; Katja Wiech; Ted J Kaptchuk; Regine Klinger; John M Kelley Journal: Psychother Psychosom Date: 2018-06-12 Impact factor: 17.659
Authors: Neal Shore; Ronald Tutrone; Mitchell Efros; Mohamed Bidair; Barton Wachs; Susan Kalota; Sheldon Freedman; James Bailen; Richard Levin; Stephen Richardson; Jed Kaminetsky; Jeffrey Snyder; Barry Shepard; Kenneth Goldberg; Alan Hay; Steven Gange; Ivan Grunberger Journal: World J Urol Date: 2018-01-29 Impact factor: 4.226