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Association between trial registration and treatment effect estimates: a meta-epidemiological study

BACKGROUND: To increase transparency in research, the International Committee of Medical Journal Editors required, in 2005, prospective registration of clinical trials as a condition to publication. However, many trials remain unregistered or retrospectively registered. We aimed to assess the associ...

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Autores principales: Dechartres, Agnès, Ravaud, Philippe, Atal, Ignacio, Riveros, Carolina, Boutron, Isabelle
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4932748/
https://www.ncbi.nlm.nih.gov/pubmed/27377062
http://dx.doi.org/10.1186/s12916-016-0639-x
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author Dechartres, Agnès
Ravaud, Philippe
Atal, Ignacio
Riveros, Carolina
Boutron, Isabelle
author_facet Dechartres, Agnès
Ravaud, Philippe
Atal, Ignacio
Riveros, Carolina
Boutron, Isabelle
author_sort Dechartres, Agnès
collection PubMed
description BACKGROUND: To increase transparency in research, the International Committee of Medical Journal Editors required, in 2005, prospective registration of clinical trials as a condition to publication. However, many trials remain unregistered or retrospectively registered. We aimed to assess the association between trial prospective registration and treatment effect estimates. METHODS: This is a meta-epidemiological study based on all Cochrane reviews published between March 2011 and September 2014 with meta-analyses of a binary outcome including three or more randomised controlled trials published after 2006. We extracted trial general characteristics and results from the Cochrane reviews. For each trial, we searched for registration in the report’s full text, contacted the corresponding author if not reported and searched ClinicalTrials.gov and the International Clinical Trials Registry Platform in case of no response. We classified each trial as prospectively registered (i.e. registered before the start date); retrospectively registered, distinguishing trials registered before and after the primary completion date; and not registered. Treatment effect estimates of prospectively registered and other trials were compared by the ratio of odds ratio (ROR) (ROR <1 indicates larger effects in trials not prospectively registered). RESULTS: We identified 67 meta-analyses (322 trials). Overall, 225/322 trials (70 %) were registered, 74 (33 %) prospectively and 142 (63 %) retrospectively; 88 were registered before the primary completion date and 54 after. Unregistered or retrospectively registered trials tended to show larger treatment effect estimates than prospectively registered trials (combined ROR = 0.81, 95 % CI 0.65–1.02, based on 32 contributing meta-analyses). Trials unregistered or registered after the primary completion date tended to show larger treatment effect estimates than those registered before this date (combined ROR = 0.84, 95 % CI 0.71–1.01, based on 43 contributing meta-analyses). CONCLUSIONS: Lack of trial prospective registration may be associated with larger treatment effect estimates. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-016-0639-x) contains supplementary material, which is available to authorized users.
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spelling pubmed-49327482016-07-06 Association between trial registration and treatment effect estimates: a meta-epidemiological study Dechartres, Agnès Ravaud, Philippe Atal, Ignacio Riveros, Carolina Boutron, Isabelle BMC Med Research Article BACKGROUND: To increase transparency in research, the International Committee of Medical Journal Editors required, in 2005, prospective registration of clinical trials as a condition to publication. However, many trials remain unregistered or retrospectively registered. We aimed to assess the association between trial prospective registration and treatment effect estimates. METHODS: This is a meta-epidemiological study based on all Cochrane reviews published between March 2011 and September 2014 with meta-analyses of a binary outcome including three or more randomised controlled trials published after 2006. We extracted trial general characteristics and results from the Cochrane reviews. For each trial, we searched for registration in the report’s full text, contacted the corresponding author if not reported and searched ClinicalTrials.gov and the International Clinical Trials Registry Platform in case of no response. We classified each trial as prospectively registered (i.e. registered before the start date); retrospectively registered, distinguishing trials registered before and after the primary completion date; and not registered. Treatment effect estimates of prospectively registered and other trials were compared by the ratio of odds ratio (ROR) (ROR <1 indicates larger effects in trials not prospectively registered). RESULTS: We identified 67 meta-analyses (322 trials). Overall, 225/322 trials (70 %) were registered, 74 (33 %) prospectively and 142 (63 %) retrospectively; 88 were registered before the primary completion date and 54 after. Unregistered or retrospectively registered trials tended to show larger treatment effect estimates than prospectively registered trials (combined ROR = 0.81, 95 % CI 0.65–1.02, based on 32 contributing meta-analyses). Trials unregistered or registered after the primary completion date tended to show larger treatment effect estimates than those registered before this date (combined ROR = 0.84, 95 % CI 0.71–1.01, based on 43 contributing meta-analyses). CONCLUSIONS: Lack of trial prospective registration may be associated with larger treatment effect estimates. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-016-0639-x) contains supplementary material, which is available to authorized users. BioMed Central 2016-07-04 /pmc/articles/PMC4932748/ /pubmed/27377062 http://dx.doi.org/10.1186/s12916-016-0639-x Text en © The Author(s). 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Dechartres, Agnès
Ravaud, Philippe
Atal, Ignacio
Riveros, Carolina
Boutron, Isabelle
Association between trial registration and treatment effect estimates: a meta-epidemiological study
title Association between trial registration and treatment effect estimates: a meta-epidemiological study
title_full Association between trial registration and treatment effect estimates: a meta-epidemiological study
title_fullStr Association between trial registration and treatment effect estimates: a meta-epidemiological study
title_full_unstemmed Association between trial registration and treatment effect estimates: a meta-epidemiological study
title_short Association between trial registration and treatment effect estimates: a meta-epidemiological study
title_sort association between trial registration and treatment effect estimates: a meta-epidemiological study
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4932748/
https://www.ncbi.nlm.nih.gov/pubmed/27377062
http://dx.doi.org/10.1186/s12916-016-0639-x
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