Doctor: Amélie Yavchitz

Title: Dissemination of scientific findings from randomized controlled trials and systematic reviews

Supervisor: Isabelle Boutron

Doctoral school: ED 393 Epidemiology and Biomedical Information Sciences, Université Paris Cité

Date of thesis defense: 13/10/2015

Jury: Dominique Fletcher, Stefan Michiels, France Mentré, Bruno Falissard, Isabelle Boutron


Randomized controlled trials (RCT) and systematic reviews and meta-analyses are the cornerstones of therapeutic evaluation because they are considered to provide the highest  level of evidence. An accurate and complete presentation by authors of all the important information in report of such studies is essential to allow a critical appraisal of the study by readers. We define spin as a specific way of reporting, deliberate or not, that can lead to a “beautification” of the data. No study evaluated the dissemination of spin and their impact on the study’s interpretation. Furthermore, several studies focused on different elements that can affect the interpretation of research results, but none assessed the impact of adding a limitation section in abstract of systematic reviews. Finally, spin are frequent and classification was developed for spin in RCTs, however no classification of spin in systematic reviews and meta-analyses have been proposed.

Our work showed that 1) spin are disseminated in press releases and news and they are associated with an overestimation of the beneficial effect of treatment, 2) the addition of a limitation section in abstract of systematic reviews and meta-analysis does not impact the confidence in the study results by readers. Finally, we developed a classification scheme of spin in systematic reviews and meta-analyzes, and we ranked spin in abstract according to their perceived severity (i.e. the likelihood to distort the interpretation of the review).

Link to download the thesis (written in French)

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