Institute of Medical Biometry and Statistics (IMBI)

This project is completed and this page is archived. Last change on this page was 2011.

Two systematic reviews on the size of effects of different placebo interventions

Funding: BMBF, Förderkennzeichen 01KG0924

Duration: 1.11.2009 to 30.04.2011

Objectives

Review 1: To investigate whether there is evidence from /direct/ comparisons in randomized clinical trials that some placebo or sham interventions are more effective than others. Review 2: To investigate whether there is evidence from /indirect/ comparisons of randomized clinical trials on the prophylaxis of migraine that some placebo or sham interventions are more effective than others.

Summary

Background: There is increasing evidence that physical or behavioural sham interventions might have more potent placebo effects than, for example, a drug placebo. This could have important implications for the interpretation of clinical trials and decision making. Objective: In the proposed project we will perform two reviews. In review 1 we will investigate whether there is evidence from direct comparisons in randomized clinical trials that some placebo or sham interventions are more effective than others. In review 2 we will investigate whether there is evidence from indirect comparisons of randomized clinical trials on the prophylaxis of migraine that some placebo or sham interventions are more effective than others. Methods: In review 1 we will only include randomized trials which include two different types of placebo interventions (for example, a drug placebo and sham biofeedback). As eligible trials will come from various medical fields findings will be summarized mainly in a descriptive manner, although we will try to perform exploratory quantitative analyses. In review 2 we will include placebo-/sham-controlled trials of any intervention for migraine prophylaxis reporting relevant outcomes (response and/or headache frequency). Pooled effect sizes (for pre-post changes in true treatment and placebo/sham groups as well as for between-group differences) for subgroups of trials using similar placebo or sham interventions will be calculated and compared in an exploratory manner.

Publications

• Meissner K, Fässler M, Rücker G, Kleijnen J, Hróbjartsson A, Schneider A, Antes G, Linde K. Differential Effectiveness of Placebo Treatments: A Systematic Review of Migraine Prophylaxis. JAMA Intern Med. 2013 Oct 14. doi: 10.1001/jamainternmed.2013.10391. [Epub ahead of print] PMID: 24126676