Response to: stated conclusion about industry funding is opposite to what the paper's data show: letter regarding “Selective outcome reporting in obesity clinical trials: a cross-sectional review”

Background: Despite evidence of selective outcome reporting across multiple disciplines, this has not yet been assessed in trials studying the effects of exercise in people with cancer. Therefore, the purpose of our study was to explore prospectively registered randomised controlled trials (RCTs) in exercise oncology for evidence of selective outcome reporting. Methods: Eligible trials were RCTs that 1) investigated the effects of at least partially supervised exercise interventions in people with cancer; 2) were preregistered (i.e. registered before the first patient was recruited) on a clinical trials registry; and 3) reported results in a peer-reviewed published manuscript. We searched the PubMed database from the year of inception to September 2020 to identify eligible exercise oncology RCTs clinical trial registries. Eligible trial registrations and linked published manuscripts were compared to identify the proportion of sufficiently preregistered outcomes reported correctly in the manuscripts, and cases of outcome omission, switching, and silently introduction of non- novel outcomes. Results: We identified 31 eligible RCTs and 46 that were ineligible due to retrospective registration. Of the 405 total prespecified outcomes across the 31 eligible trials, only 6.2% were preregistered complete methodological detail. Only 16% (n=148/929) of outcomes reported in published results manuscripts were linked with sufficiently preregistered outcomes without outcome switching. We found 85 total cases of outcome switching. A high proportion (41%) of preregistered outcomes were omitted from the published results manuscripts, and many published outcomes (n=394; 42.4%) were novel outcomes that had been silently introduced (median, min-max=10, 0-50 per trial). We found no examples of preregistered efficacy outcomes that were measured, assessed, and analysed as planned. Conclusions: We found evidence suggestive of widespread selective outcome reporting and non-reporting bias (omitted preregistered outcomes, outcome switching, and silently introduced novel outcomes). The existence of such reporting discrepancies has implications for the integrity and credibility of RCTs in exercise oncology.

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Publication bias in clinical trials

10.53731/r294649-6f79289-8cw3m ◽

2009 ◽

Author(s):

Martin Fenner

Keyword(s):

Clinical Trial ◽

Clinical Trials ◽

England Journal ◽

New England ◽

Cancer Patients ◽

Publication Bias ◽

Secondary Outcome ◽

Selective Outcome Reporting ◽

Outcome Reporting

Last week the New England Journal of Medicine (NEJM) published a paper on selective outcome reporting in clinical trials (Vedula et al. 2009). The primary and secondary outcome(s) of a clinical trial could for example be survival in cancer patients or ...

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Peer reviewed evaluation of registered end-points of randomised trials (the PRE-REPORT study): protocol for a stepped-wedge, cluster-randomised trial

BMJ Open ◽

10.1136/bmjopen-2018-028694 ◽

2019 ◽

Vol 9 (5) ◽

pp. e028694

Author(s):

Christopher W Jones ◽

Amanda Adams ◽

Mark A Weaver ◽

Sara Schroter ◽

Benjamin S Misemer ◽

...

Keyword(s):

Clinical Trials ◽

Peer Review ◽

Primary Outcome ◽

Randomised Trial ◽

Cluster Randomised Trial ◽

Stepped Wedge ◽

Selective Outcome Reporting ◽

Outcome Reporting ◽

Cluster Randomised ◽

Peer Reviewers

IntroductionClinical trials are critical to the advancement of medical knowledge. However, the reliability of trial conclusions depends in part on consistency between pre-planned and reported study outcomes. Unfortunately, selective outcome reporting, in which outcomes reported in published manuscripts differ from pre-specified study outcomes, is common. Trial registries such as ClinicalTrials.gov have the potential to help identify and stop selective outcome reporting during peer review by allowing peer reviewers to compare outcomes between registry entries and submitted manuscripts. However, the persistently high rate of selective outcome reporting among published clinical trials indicates that the current peer review process at most journals does not effectively address the problem of selective outcome reporting.Methods and analysisPRE-REPORT is a stepped-wedge cluster-randomised trial that will test whether providing peer reviewers with a summary of registered, pre-specified primary trial outcomes decreases inconsistencies between prospectively registered and published primary outcomes. Peer reviewed manuscripts describing clinical trial results will be included. Eligible manuscripts submitted to each participating journal during the study period will comprise each cluster. After an initial control phase, journals will transition to the intervention phase in random order, after which peer reviewers will be emailed registry information consisting of the date of registration and any prospectively defined primary outcomes. Blinded outcome assessors will compare registered and published primary outcomes for all included trials. The primary PRE-REPORT outcome is the presence of a published primary outcome that is consistent with a prospectively defined primary outcome in the study’s trial registry. The primary outcome will be analysed using a mixed effect logistical regression model to compare results between the intervention and control phases.Ethics and disseminationThe Cooper Health System Institutional Review Board determined that this study does not meet criteria for human subject research. Findings will be published in peer-reviewed journals.Trial registration numberISRCTN41225307; Pre-results.

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Evaluation of selective outcome reporting and trial registration practices among addiction clinical trials

Addiction ◽

10.1111/add.14902 ◽

2020 ◽

Vol 115 (6) ◽

pp. 1172-1179 ◽

Cited By ~ 1

Author(s):

Matt Vassar ◽

William Roberts ◽

Craig M. Cooper ◽

Cole Wayant ◽

Michael Bibens

Keyword(s):

Clinical Trials ◽

Trial Registration ◽

Selective Outcome Reporting ◽

Outcome Reporting

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Prevalence of primary outcome changes in clinical trials registered on ClinicalTrials.gov: a cross-sectional study

F1000Research ◽

10.12688/f1000research.3784.1 ◽

2014 ◽

Vol 3 ◽

pp. 77 ◽

Cited By ~ 26

Author(s):

Sreeram V. Ramagopalan ◽

Andrew P. Skingsley ◽

Lahiru Handunnetthi ◽

Michelle Klingel ◽

Daniel Magnus ◽

...

Keyword(s):

Clinical Trials ◽

Primary Outcome ◽

Significant Proportion ◽

Cross Sectional Study ◽

Industry Funding ◽

Cross Sectional ◽

Start Date ◽

Important Principle ◽

Completion Date ◽

Clinical Trials Registry

Background: An important principle in the good conduct of clinical trials is that a summary of the trial protocol, with a pre-defined primary outcome, should be freely available before the study commences. The clinical trials registry ClinicalTrials.gov provides one method of doing this, and once the trial is registered, any changes made to the primary outcome are documented. The objectives of this study were: to assess the proportion of registered trials on ClinicalTrials.gov that had the primary outcome changed; to assess when the primary outcome was changed in relation to the listed study start and end dates and to assess whether the primary outcome change had any relation to the study sponsor.Methods: A cross-sectional analysis of all interventional clinical trials registered on ClinicalTrials.gov as of 25 October 2012 was performed. The main outcome was any change made to the initially listed primary outcome and the time of the change in relation to the trial start and end date.Findings: Our analysis showed that 28229 of 89204 (31.7%) registered studies had their primary outcome changed. Industry funding was associated with all primary outcome changes, odds ratio (OR)= 1.36, 95% confidence interval (CI)=1.31-1.41, p<0.001; with primary outcome changes after study start date OR=1.37, 95% CI=1.32-1.42, p<0.001; with primary outcome changes after primary completion date OR=1.84, 95% CI=1.75-1.94, p<0.001 and with primary outcome changes after study completion date OR=1.82, 95% CI=1.73-1.91, p<0.001. Conclusions A significant proportion of interventional trials registered on ClinicalTrials.gov have their primary outcomes altered after the listed study start and completion dates. These changes are associated with funding source.

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Trial registration and selective outcome reporting in 585 clinical trials investigating drugs for prevention of postoperative nausea and vomiting

BMC Anesthesiology ◽

10.1186/s12871-021-01464-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Manuel Riemer ◽

Peter Kranke ◽

Antonia Helf ◽

Debora Mayer ◽

Maria Popp ◽

...

Keyword(s):

Clinical Trials ◽

High Risk ◽

Postoperative Nausea ◽

Cochrane Review ◽

Postoperative Nausea And Vomiting ◽

Risk Of Bias ◽

The Body ◽

Trial Registration ◽

Selective Outcome Reporting ◽

Outcome Reporting

Abstract Background Selective outcome reporting in clinical trials introduces bias in the body of evidence distorting clinical decision making. Trial registration aims to prevent this bias and is suggested by the International Committee of Medical Journal Editors (ICMJE) since 2004. Methods The 585 randomized controlled trials (RCTs) published between 1965 and 2017 that were included in a recently published Cochrane review on antiemetic drugs for prevention of postoperative nausea and vomiting were selected. In a retrospective study, we assessed trial registration and selective outcome reporting by comparing study publications with their registered protocols according to the ‘Cochrane Risk of bias’ assessment tool 1.0. Results In the Cochrane review, the first study which referred to a registered trial protocol was published in 2004. Of all 585 trials included in the Cochrane review, 334 RCTs were published in 2004 or later, of which only 22% (75/334) were registered. Among the registered trials, 36% (27/75) were pro- and 64% (48/75) were retrospectively registered. 41% (11/27) of the prospectively registered trials were free of selective outcome reporting bias, 22% (6/27) were incompletely registered and assessed as unclear risk, and 37% (10/27) were assessed as high risk. Major outcome discrepancies between registered and published high risk trials were a change from the registered primary to a published secondary outcome (32%), a new primary outcome (26%), and different outcome assessment times (26%). Among trials with high risk of selective outcome reporting 80% favoured at least one statistically significant result. Registered trials were assessed more often as ‘overall low risk of bias’ compared to non-registered trials (64% vs 28%). Conclusions In 2017, 13 years after the ICMJE declared prospective protocol registration a necessity for reliable clinical studies, the frequency and quality of trial registration in the field of PONV is very poor. Selective outcome reporting reduces trustworthiness in findings of clinical trials. Investigators and clinicians should be aware that only following a properly registered protocol and transparently reporting of predefined outcomes, regardless of the direction and significance of the result, will ultimately strengthen the body of evidence in the field of PONV research in the future.

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