Systematic review protocol assessing the processes for linking clinical trial registries and their published results

Introduction Clinical trial registries are an important source of information for tracking clinical trials from their inception through to their reporting, and have been used to measure publication bias and outcome reporting bias. Our aim is to survey and quantify the processes that have been used to identify links between clinical trial registries and published trial reports in studies that rely on these links to evaluate the completeness and accuracy of trial reporting. Methods and analysis We will identify studies that describe a process for identifying the links between a trial registry included in the WHO International Clinical Trial Registry Platform and published trial results, and use those links to evaluate the completeness and accuracy of trial reporting. Information extracted from the studies will include the purpose and application domain of the study, registries used or searched, processes by which the links were identified, the study period and proportions for which links were found. We will summarise what is known about the number and availability of links between clinical trial registries and published results, and examine how automatic linking, inference and inquiry processes have been used to identify links since the introduction of trial registries. Ethics and dissemination The systematic review is focused on the analysis of secondary data and does not require ethics approval. The results of the systematic review will be used to inform standard processes used to identify links to and from clinical trial registries in studies that evaluate the completeness and accuracy of clinical trial reports, as well as systematic reviews. Our findings will be disseminated by publishing the systematic review in a peer-reviewed journal, and by engaging with stakeholders from clinical trial registries and bibliographic databases.

[1]  G GordilloPaniagua,et al.  The International Committee of Medical Journal Editors , 1981 .

[2]  Peter C Gøtzsche,et al.  Searching for unpublished data for Cochrane reviews: cross sectional study , 2013, BMJ : British Medical Journal.

[3]  S. Ananiadou,et al.  Using text mining for study identification in systematic reviews: a systematic review of current approaches , 2015, Systematic Reviews.

[4]  Nicholas C. Ide,et al.  The ClinicalTrials.gov results database--update and key issues. , 2011, The New England journal of medicine.

[5]  J. Pérez Martín.  [International Committee of Medical Journal Editors]. , 2008, Revista alergia Mexico.

[6]  A. McCray.  Better Access to Information about Clinical Trials , 2000, Annals of Internal Medicine.

[7]  G. ter Riet,et al.  Two prognostic indicators of the publication rate of clinical studies were available during ethical review. , 2010, Journal of clinical epidemiology.

[8]  M. Lauer,et al.  Publication of trials funded by the National Heart, Lung, and Blood Institute. , 2014, The New England journal of medicine.

[9]  P. Lee,et al.  Publication bias in meta-analysis: its causes and consequences. , 2000, Journal of clinical epidemiology.

[10]  Douglas G Altman,et al.  The impact of outcome reporting bias in randomised controlled trials on a cohort of systematic reviews , 2010, BMJ : British Medical Journal.

[11]  Isabelle Boutron,et al.  Timing and Completeness of Trial Results Posted at ClinicalTrials.gov and Published in Journals , 2013, PLoS medicine.

[12]  A. Marušić,et al.  Changes to registration elements and results in a cohort of Clinicaltrials.gov trials were not reflected in published articles. , 2016, Journal of clinical epidemiology.

[13]  Kenneth D. Mandl,et al.  Outcome Reporting Among Drug Trials Registered in ClinicalTrials.gov , 2010, Annals of Internal Medicine.

[14]  James J. Cimino,et al.  Precision and Negative Predictive Value of Links between ClinicalTrials.gov and PubMed , 2012, AMIA.

[15]  Dean Giustini,et al.  Comparing the coverage, recall, and precision of searches for 120 systematic reviews in Embase, MEDLINE, and Google Scholar: a prospective study , 2016, Systematic Reviews.

[16]  James J. Cimino,et al.  Linking ClinicalTrials.gov and PubMed to Track Results of Interventional Human Clinical Trials , 2013, PloS one.

[17]  G. Guyatt,et al.  When and how to update systematic reviews: consensus and checklist , 2016, British Medical Journal.

[18]  Harlan M Krumholz,et al.  Publication of NIH funded trials registered in ClinicalTrials.gov: cross sectional analysis , 2012, BMJ : British Medical Journal.

[19]  Aaron M. Cohen,et al.  Studying the potential impact of automated document classification on scheduling a systematic review update , 2012, BMC Medical Informatics and Decision Making.

[20]  J. Thornton,et al.  Discrepancies between registration and publication of randomised controlled trials: an observational study , 2014, JRSM open.

[21]  George Hripcsak,et al.  Publication bias in clinical trials of electronic health records , 2013, J. Biomed. Informatics.

[22]  Timothy F. Platts-Mills,et al.  Comparison of registered and published outcomes in randomized controlled trials: a systematic review , 2015, BMC Medicine.

[23]  J. Ioannidis.  Effect of the statistical significance of results on the time to completion and publication of randomized efficacy trials. , 1998, JAMA.

[24]  David Moher,et al.  Comparison of registered and published primary outcomes in randomized controlled trials. , 2009, JAMA.

[25]  John Hoey,et al.  Is this clinical trial fully registered? A statement from the International Committee of Medical Journal Editors , 2005, The Lancet.

[26]  R. McCarthy,et al.  Discrepancies Between Randomized Controlled Trial Registry Entries and Content of Corresponding Manuscripts Reported in Anesthesiology Journals , 2015, Anesthesia and analgesia.

[27]  H. Krumholz,et al.  Time to publication among completed clinical trials. , 2013, JAMA internal medicine.

[28]  I. Leviton,et al.  Registering clinical trials. , 2003, JAMA.

[29]  M. Airaksinen,et al.  Automated dose dispensing service for primary healthcare patients: a systematic review , 2013, Systematic Reviews.

[30]  Douglas G Altman,et al.  Comparison of protocols and registry entries to published reports for randomised controlled trials. , 2011, The Cochrane database of systematic reviews.

[31]  Eric Manheimer,et al.  Survey of public information about ongoing clinical trials funded by industry: evaluation of completeness and accessibility , 2002, British medical journal.

[32]  P. Gøtzsche,et al.  Strategies for obtaining unpublished drug trial data: a qualitative interview study , 2013, Systematic Reviews.

[33]  L. Preston,et al.  Improving search efficiency for systematic reviews of diagnostic test accuracy: an exploratory study to assess the viability of limiting to MEDLINE, EMBASE and reference checking , 2015, Systematic Reviews.

[34]  Christopher W. Jones,et al.  Non-publication of large randomized clinical trials: cross sectional analysis , 2013, BMJ.

[35]  Alexander Tsertsvadze,et al.  Updating Systematic Reviews: An International Survey , 2010, PloS one.

[36]  Harlan M. Krumholz,et al.  Trial Publication after Registration in ClinicalTrials.Gov: A Cross-Sectional Analysis , 2009, PLoS medicine.

[37]  R. Ewart,et al.  Undisclosed Changes in Outcomes in Randomized Controlled Trials: An Observational Study , 2009, The Annals of Family Medicine.

[38]  Sally Hopewell,et al.  A multicomponent decision tool for prioritising the updating of systematic reviews , 2013, BMJ.

[39]  Philippe Ravaud,et al.  Comparison of serious adverse events posted at ClinicalTrials.gov and published in corresponding journal articles , 2015, BMC Medicine.

[40]  Christopher W. Jones,et al.  Clinical trials registries are under-utilized in the conduct of systematic reviews: a cross-sectional analysis , 2014, Systematic Reviews.

[41]  Andrew Forbes,et al.  Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions. , 2014, The Cochrane database of systematic reviews.