Original ArticleResult dissemination from clinical trials conducted at German university medical centers was delayed and incomplete
Section snippets
Background
The results of clinical trials build the backbone of evidence-based medicine. They inform clinical decision-making [1] and health technology assessment [2], [3]. They also inform decision-making within ongoing trials and decision-making related to the design, review, and funding of new trials [4]. Nondissemination or delayed dissemination of trial results negatively affects all of these decision-making processes [5], [6], [7], [8]. For 3 decades, studies investigated and criticized this
Methods
The protocol for this project, including all methodological details for sampling and following up clinical trials for data extraction, and statistical analyses were preregistered with the Open Science Framework (OSF) and continuously updated for amendments (https://osf.io/fh426/). In the following sections, we summarize the methods.
Demographic data
We identified 2,132 clinical trials via clinicaltrial.gov (n = 1,905) and DRKS (n = 227) that (1) recruited trial participants from at least one German UMC and (2) had their PCD (last visit of last patient for a primary outcome measure) between 2009 and 2013. These trials included 506,876 anticipated participants.
Altogether, 71% (n = 1,457) of all trials were counted as lead trial for one of the corresponding German UMCs. Of these 1,457 lead trials, 502 (35%) investigated drugs and 266 (18%)
Discussion
In this study, we demonstrate that only 39% of all registered clinical trials conducted at one of the 36 German UMCs published their results in a timely manner within 24 months after the trial's CD. This rate further decreases to 26% when applying standard search strategies. Six years after the CD and with the most extensive search strategies, 26% of all trials still remain unpublished.
For the following reasons, this high proportion of delayed or omitted result dissemination is unethical and a
CRediT authorship contribution statement
Susanne Wieschowski: Methodology, Formal analysis, Writing - original draft, Writing - review & editing. Nico Riedel: Software, Formal analysis, Data curation, Writing - original draft, Writing - review & editing. Katharina Wollmann: Formal analysis, Writing - review & editing. Hannes Kahrass: Formal analysis, Writing - review & editing. Stephanie Müller-Ohlraun: Formal analysis, Writing - review & editing. Christopher Schürmann: Formal analysis, Writing - review & editing. Sean Kelley:
Acknowledgments
Intramural funding was obtained for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
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2022, Contemporary Clinical TrialsCitation Excerpt :The overall percentage of disseminated results, which included summary reports on trial registries, was slightly higher (71%). These findings are in line with publication proportions reported in recent literature, although most studies have shorter follow up durations [1–4]. We found that 5 years after trial completion, only a few additional publications were found.
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2022, Journal of Clinical EpidemiologyCitation Excerpt :Even five years after completion, 30% still did not disseminate any results via journal publications or via summary results in the two registries. Both the proportions published after two and five years show only slight improvements (4 and 3 percentage points higher, respectively) compared to our previous study on results reporting of clinical trials from German UMCs completed between 2009 and 2013 [1]. UMCs (as sponsors) and clinical trialists (as PIs) should launch a concerted effort to rectify past ethics violations by retrospectively making public the results of all their unreported trials.
Clinical trials were missing from regulatory documents of extended-release methylphenidate for ADHD in adults: a case study of public documents
2022, Journal of Clinical EpidemiologyCitation Excerpt :We may have missed some publicly funded trials with industry-involvement. Selective reporting of publicly funded trials is particularly pronounced [60,61], and sometimes the industry-involvement has not been declared in publications, even when the trial was later used in a registration application [62]. We identified limitations in the current drug regulatory system with potentially serious consequences for the reliability of drug approvals.
Conflict of interest: All authors are affiliated with a German UMC in Berlin, Hannover, or Freiburg. No further conflicts of interest exist.
Software availability: The R script used as part of this study is available from https://doi.org/10.17605/OSF.IO/FH426. Archived source code at time of publication: https://doi.org/10.17605/OSF.IO/FH426. License: MIT License.
Data availability: All data underlying the results are available as part of the article and at OSF: Data set 1: IntoValue. https://doi.org/10.17605/OSF.IO/FH426. The data are available under a CC0 license. No additional source data are required.
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These authors contributed equally to this work.