Clinical trial registry use in anaesthesiology systematic reviews: A cross-sectional study of systematic reviews published in anaesthesiology journals and the Cochrane Library

Availability of results of clinical trials registered on EU Clinical Trials Register: cross sectional audit study

Objective

To identify the availability of results for trials registered on the European Union Clinical Trials Register (EUCTR) compared with other dissemination routes to understand its value as a results repository.

Design

Cross sectional audit study.

Setting

EUCTR protocols and results sections, data extracted 1-3 December 2020.

Population

Random sample of 500 trials registered on EUCTR with a completion date of more than two years from the beginning of searches (ie, 1 December 2018).

Main outcome measures

Proportion of trials with results across the examined dissemination routes (EUCTR, ClinicalTrials.gov, ISRCTN registry, and journal publications), and for each dissemination route individually. Prespecified secondary outcomes were number and proportion of unique results, and the timing of results, for each dissemination route.

Results

In the sample of 500 trials, availability of results on EUCTR (53.2%, 95% confidence interval 48.8% to 57.6%) was similar to the peer reviewed literature (58.6%, 54.3% to 62.9%) and exceeded the proportion of results available on other registries with matched records. Among the 383 trials with any results, 55 (14.4%, 10.9% to 17.9%) were only available on EUCTR. Also, after the launch of the EUCTR results database, median time to results was fastest on EUCTR (1142 days, 95% confidence interval 812 to 1492), comparable with journal publications (1226 days, 1074 to 1551), and exceeding ClinicalTrials.gov (3321 days, 1653 to undefined). For 117 trials (23.4%, 19.7% to 27.1%), however, results were published elsewhere but not submitted to the EUCTR registry, and no results were located in any dissemination route for 117 trials (23.4%, 19.7% to 27.1).

Conclusions

EUCTR should be considered in results searches for systematic reviews and can help researchers and the public to access the results of clinical trials, unavailable elsewhere, in a timely way. Reporting requirements, such as the EU's, can help in avoiding research waste by ensuring results are reported. The registry's true value, however, is unrealised because of inadequate compliance with EU guidelines, and problems with data quality that complicate the routine use of the registry. As the EU transitions to a new registry, continuing to emphasise the importance of EUCTR and the provision of timely and complete data is critical. For the future, EUCTR will still hold important information from the past two decades of clinical research in Europe. With increased efforts from sponsors and regulators, the registry can continue to grow as a source of results of clinical trials, many of which might be unavailable from other dissemination routes.

Trial Registry Searches In Plastic Surgery Systematic Reviews: A Meta-epidemiological Study

INTRODUCTION

Clinical trial registry searches for unpublished clinical trial data are a means of mitigating publication bias within systematic reviews (SRs). The purpose of our study is to look at the rate of clinical trial registry searches conducted by SRs in the top five Plastic and Reconstructive Surgery journals.

METHODS

We identified the top five plastic and reconstructive surgery journals using the Google h-5 index. We then searched Pubmed for SRs published in these journals and compared them to plastic surgery SRs published in the Cochrane Collaboration for SRs over the last 5 y. We included all SRs that were published within these top five journals and Cochrane between December 6, 2016 and December 6, 2021. We then conducted a secondary analysis on clinicaltrials.gov looking for unpublished clinical trials for 100 randomized SRs that did not conduct a clinical trial registry search.

RESULTS

In SRs, 3.3% (17/512) from plastic surgery journals conducted trial registry searches. In comparison, 95.0% (38/40) of Cochrane Collaboration SRs conducted trial registry searches. Our secondary analysis found that 50% (50/100) of SRs could have included at least one unpublished clinical trial data set.

CONCLUSIONS

We found that plastic surgery SRs rarely include searches for unpublished clinical trial data in clinical trial registries. To improve the data completeness of SRs in plastic surgery journals, we recommend journals alter their author guidelines to require a clinical trial registry search for unpublished literature.

Clinical trial data-sharing policies among journals, funding agencies, foundations, and other professional organizations: a scoping review

BACKGROUND AND OBJECTIVES

To identify the similarities and differences in data-sharing policies for clinical trial data that are endorsed by biomedical journals, funding agencies, and other professional organizations. Additionally, to determine the beliefs, and opinions regarding data-sharing policies for clinical trials discussed in articles published in biomedical journals.

METHODS

Two searches were conducted, a bibliographic search for published articles that present beliefs, opinions, similarities, and differences regarding policies governing the sharing of clinical trial data. The second search analyzed the gray literature (non-peer-reviewed publications) to identify important data-sharing policies in selected biomedical journals, foundations, funding agencies, and other professional organizations.

RESULTS

A total of 471 articles were included after database search and screening, with 45 from the bibliographic search and 426 from the gray literature search. A total of 424 data-sharing policies were included. Fourteen of the 45 published articles from the bibliographic search (31.1%) discussed only advantages specific to data-sharing policies, 27 (27/45; 60%) discussed both advantages and disadvantages, and 4 (4/45; 8.9%) discussed only disadvantages specific. A total of 216 journals (of 270; 80%) specified a data-sharing policy provided by the journal itself. One hundred industry data-sharing policies were included, and 32 (32%) referenced a data-sharing policy on their website. One hundred and thirty-six (42%) organizations (of 327) specified a data-sharing policy.

CONCLUSION

We found many similarities listed as advantages to data-sharing and fewer disadvantages were discussed within the literature. Additionally, we found a wide variety of commonalities and differences-such as the lack of standardization between policies, and inadequately addressed details regarding the accessibility of research data-that exist in data-sharing policies endorsed by biomedical journals, funding agencies, and other professional organizations. Our study may not include information on all data sharing policies and our data is limited to the entities' descriptions of each policy.

Impact of searching clinical trials registers in systematic reviews of pharmaceutical and non-pharmaceutical interventions: Reanalysis of meta-analyses

Systematic reviewers are advised to search trials registers to minimise risk of reporting biases. However, there has been little research on the impact of searching trials registers on the results of meta-analyses. We aimed to evaluate the impact of searching clinical trials registers for systematic reviews of pharmaceutical or non-pharmaceutical interventions. We searched PubMed, Scopus, Science Citation Index and Social Sciences Citation Index, and Education Collection for systematic reviews with meta-analyses indexed from 2 November to 2 December 2020. A random sample of systematic reviews was initially drawn, and for reviews which considered randomised trials eligible for inclusion, which had not searched a trials register, we searched ClinicalTrials.gov, EudraCT, ANZCTR, and the WHO ICTRP search portal for eligible trials. We compared meta-analytic effect estimates before and after including results from additional trials identified. We found additional trials for 63% (63/101) of eligible reviews; however, trials with results that could contribute to a meta-analysis were identified for only 20% (20/101) of the reviews. On average, there was no difference in the meta-analytic effect estimates before versus after adding the new trials. In summary, searching clinical trial registers led to identification of additional trials for many reviews; however, very few trials had results available for inclusion in meta-analyses. Including results from the new trials led to no change in the meta-analytic estimates, on average. Trials registers would be even more valuable to systematic reviewers if more trialists made use of them (i.e., registered their trials and posted results in a timely manner).

Financial conflicts of interest during meetings of the cardiovascular and renal drugs advisory committee

CONTEXT

The Cardiovascular and Renal Drugs Advisory Committee (CRDAC) of the Food and Drug Administration (FDA) reviews safety and efficacy data for cardiovascular and renal drugs, ultimately making recommendations to the Commissioner of Food and Drugs for approval. The Open Public Hearing segment of these meetings allows for patients, advocates, healthcare professionals, clinical trialists, and members of the public to provide testimony, which often results in expressing their preference for, or against, drug approval. Prior to providing testimony, the public speakers are highly encouraged to disclose any financial conflicts of interest (FCOIs) with the sponsor or other groups. Given the potential influence of these speakers on drug approval recommendations, we investigated the industry associations disclosed by public speakers in the Open Public Hearing section of the CRDAC meetings. Previous studies, such as one done by Lurie et al. indicated that positive testimony is tied to a higher likelihood of drug approval, and because drug companies provide financial compensation for speakers to provide testimony in general, we wanted to determine the likelihood with which speakers who have an FCOI provided a positive testimony vs. those without any FCOI.

OBJECTIVES

The purpose is to evaluate whether public speakers with an FCOI are more likely to provide positive testimony regarding the drug in question during the CRDAC of the FDA between February 2009 and December 2019 through the use of publicly available transcripts.

METHODS

Independent researchers investigated public transcripts and minutes of the CRDAC meetings with public speakers (n=20). We identified all speakers, along with characteristics such as an FCOI, and classified statements utilizing a pilot-tested Google form. The data collected were analyzed utilizing Stata. The speaker's testimony was then compared with their FCOI. An ordered logistic regression was performed utilizing the speaker's testimony regarding the drug as the dependent variable.

RESULTS

Of the 88 speakers represented in our sample, 35 (35/88, 39.8%) disclosed an FCOI, most commonly regarding travel cost. Among speakers with an FCOI, 30 (30/35, 85.7%) spoke positively. Speakers with an FCOI were 4.96 times more likely to provide positive testimony (OR=4.96, 95% CI 1.67-14.78). Speakers with the disease were also more likely to provide positive testimony (OR=13.05, 95% CI 2.84-59.93).

CONCLUSIONS

Public speakers often play a role during meetings, and they may also have an FCOI, most commonly related to travel expenses. Our study shows that speakers with an FCOI are more likely to provide positive testimony. Stipulations, such as requiring disclosure of FCOI and randomizing the selection process of speakers, can help ensure the integrity of the drug approval process.

Clinical Trial Registry Use in Orthopaedic Surgery Systematic Reviews

BACKGROUND

Results from systematic reviews and meta-analyses, which have the highest level of evidence (Level I), often drive clinical decision-making and health policy. Often, unpublished trial data are omitted from systematic reviews, raising concerns about the extent of the reliability and validity of results that have been drawn from systematic reviews. We aimed to determine the extent to which systematic review authors include searches of clinical trial registries for unpublished data when conducting systematic reviews in orthopaedic surgery.

METHODS

Systematic reviews and/or meta-analyses were gathered from the top 5 orthopaedic surgery journals based on the h5-index from Google Scholar Metrics. Systematic reviews that had been published in the Cochrane Database of Systematic Reviews, which requires the inclusion of a clinical trial registry search, served as controls. For the primary outcome, each systematic review from the top 5 orthopaedic journals was screened to determine whether the authors of each study searched for unpublished data in clinical trial registries. We then compared the rate of registry searches with those in the control group. For the secondary analysis, a search of ClinicalTrials.gov was performed for unpublished trial data for 100 randomized systematic reviews.

RESULTS

All 38 of the Cochrane systematic reviews (100%) included clinical trial registry searches, while the top 5 orthopaedic journals had only 31 of 480 studies (6.5%) that looked at clinical trial registries. The secondary analysis yielded 59 of 100 systematic review articles (59.0%) that could have included unpublished clinical trial data from ≥1 studies to their sample.

CONCLUSIONS

Systematic reviews that have been published in the top orthopaedic surgery journals seldom included a search for unpublished clinical trial data.

CLINICAL RELEVANCE

The exclusion of clinical trial registry searches potentially contributes to publication bias within the orthopaedic literature. Moving forward, systematic review authors should include clinical trial registry searches for unpublished clinical trial data to provide the most accurate representation of the available evidence for systematic reviews and meta-analyses.

Clinical trial registry searches are under-utilized in systematic reviews from critical care journals: A bibliometric analysis

PURPOSE

Publication bias has a significant impact on the results of systematic reviews. Clinical trial registry searches, which include unpublished research, should be conducted when performing systematic reviews to reduce publication bias. We aimed to analyze the use of clinical trial registry searches in critical care systematic reviews.

METHODS

Systematic reviews published between 01/01/2010-02/18/2020 from the top 5 critical care journals were extracted from PubMed and screened for trial registry use. Additionally, of the studies not performing registry searches, we assessed ClinicalTrials.gov for potentially relevant trials that were missed by not performing a registry search.

RESULTS

Three hundred and twenty six systematic reviews were analyzed, of which 37 (11.3%) performed trial registry searches. Of the studies not performing clinical trial registry searches, 56% had at least 1 potentially relevant trial that was missed.

CONCLUSIONS

The omission of relevant, unpublished clinical trial results may be negatively impacting the accuracy of critical care systematic reviews. We recommend all systematic reviewers conduct clinical trial registry searches to reduce publication bias.

Clinical trial registry use in minimally invasive surgical oncology systematic reviews and meta-analyses

Publication bias can arise in systematic reviews when unpublished data are omitted and lead to inaccurate clinical decision making and adverse clinical outcomes. By conducting searches of clinical trial registries (CTRs), researchers can create more accurate systematic reviews and mitigate the risk of publication bias. The aims of this study are: to evaluate CTR use in systematic reviews and meta-analyses within the minimally invasive surgical oncology (MISO) literature; to conduct a search of ClinicalTrials.gov for a subset of reviews to determine if eligible trials exist that could have been used. This is a cross-sectional study of 197 systematic reviews and meta-analyses retrieved from PubMed. Of 137 included studies, 18 (13.1%) reported searching a CTR. Our ClinicalTrials.gov search revealed that of the 25 randomly selected systematic reviews that failed to conduct a trial registry search, 16 (64.0%) would have identified additional data sources. MISO systematic reviews and meta-analyses do not regularly use CTRs in their data collection, despite eligible trials being freely available.

Infrequent use of clinical trials registries in published systematic reviews in urology

OBJECTIVE

Validity of systematic reviews may be affected by non-publication of statistically non-significant or unfavorable clinical trial results. One function of clinical trial registries is to make these non-published studies available and thereby reduce potential publication bias. We aim to assess the use of clinical trial registries in published systematic reviews in urology.

METHODS

We identified all systematic reviews published in the five highest-impact general urology journals that publish original research between January 1 and December 31, 2017. Full-text analysis was performed to determine if protocols included searching clinical trial registries meeting WHO Registry Network criteria.

RESULTS

Of a total of 204 search results, 92 were included in the analysis as systematic reviews. The majority searched the MEDLINE (91, 98%), EMBASE (69, 75%), and Cochrane (49, 53%) databases. Based on published methods, only 16 (17%) systematic reviews searched any clinical trial registries: 14 (15%) ClinicalTrials.gov, 6 (6%) WHO International Clinical Trials Registry Platform, and 2 (2%) ISRCTN registry. Rates of searching clinical trial registries were low regardless of the journal: 8 of 34 (24%) in European Urology; 2 of 10 (20%) in BJU International; 3 of 17 (18%) in Urology; 2 of 18 (11%) in The Journal of Urology; and 1 of 13 (8%) in World Journal of Urology.

CONCLUSION

The majority of recently published systematic reviews in urology do not routinely search clinical trial registries. Inclusion of these registries can help identify unpublished trial data, which may improve the quality of systematic reviews by reducing publication bias.