Characterizing Gender Eligibility Descriptions for Clinical Trials Registered on ClinicalTrials.gov

This cross-sectional, exploratory study uses ClinicalTrials.gov data from trials initiated on or after January 18, 2017, to characterize the use of a new free-text “gender eligibility description” data field; reports the frequency of gender identity terms used; and assesses the correct or incorrect use of the field.

Characterization of key information sections in informed consent forms posted on ClinicalTrials.gov

Introduction

Recent revisions to the US Federal Common Rule governing human studies funded or conducted by the federal government require the provision of a "concise and focused" key information (KI) section in informed consent forms (ICFs). We performed a systematic study to characterize KI sections of ICFs for federally funded trials available on ClinicalTrials.gov.

Methods

We downloaded ICFs posted on ClinicalTrials.gov for treatment trials initiated on or after the revised Common Rule effective date. Trial records (n = 102) were assessed by intervention type, study phase, recruitment status, and enrollment size. The ICFs and their KI sections, if present, were characterized by page length, word count, readability, topic, and formatting elements.

Results

Of the 102 trial records, 76 had identifiable KI sections that were, on average, 10% of the total length of full ICF documents. KI readability grade level was not notably different from other sections of ICFs. Most KI sections were distinguished by section headers and included lists but contained few other formatting elements. Most KI sections included a subset of topics consistent with the basic elements of informed consent specified in the Common Rule.

Conclusion

Many of the KI sections in the study sample aligned with practices suggested in the preamble to the revised Common Rule. Further, our results suggest that some KI sections were tailored in study-specific ways. Nevertheless, guidelines on how to write concise and comprehensible KI sections would improve the utility and readability of KI sections.

Comparison of Availability of Trial Results in ClinicalTrials.gov and PubMed by Data Source and Funder Type

This study examines the dissemination of trial results by data source (ie, ClinicalTrials.gov and PubMed) and funder type (ie, industry and nonindustry).

Database resources of the National Center for Biotechnology Information in 2023

The National Center for Biotechnology Information (NCBI) provides online information resources for biology, including the GenBank® nucleic acid sequence database and the PubMed® database of citations and abstracts published in life science journals. NCBI provides search and retrieval operations for most of these data from 35 distinct databases. The E-utilities serve as the programming interface for most of these databases. New resources include the Comparative Genome Resource (CGR) and the BLAST ClusteredNR database. Resources receiving significant updates in the past year include PubMed, PMC, Bookshelf, IgBLAST, GDV, RefSeq, NCBI Virus, GenBank type assemblies, iCn3D, ClinVar, GTR, dbGaP, ALFA, ClinicalTrials.gov, Pathogen Detection, antimicrobial resistance resources, and PubChem. These resources can be accessed through the NCBI home page at https://www.ncbi.nlm.nih.gov.

Approach for reporting master protocol study designs on ClinicalTrials.gov: qualitative analysis

OBJECTIVE

To describe an approach for reporting master protocol research programs (MPRPs) that is consistent with existing good reporting practices and that uses structured information to convey the overall master protocol and design of each substudy.

DESIGN

Qualitative analysis.

DATA SOURCES

ClinicalTrials.gov trial registry.

MAIN OUTCOME MEASURES

Established goals and related practices of the trial reporting system were outlined, examples and key characteristics of MPRPs were reviewed, and specific challenges in registering and reporting summary results to databases designed for traditional clinical trial designs that rely on a model of one study per protocol were identified.

RESULTS

A reporting approach is proposed that accommodates the complex study design of MPRPs and their results. This approach involves the use of separate registration records for each substudy within one MPRP protocol (with potential exceptions noted).

CONCLUSIONS

How the proposed approach allows for clear, descriptive, structured information about each substudy's prespecified design and supports timely reporting of results after completion of each substudy is described and illustrated. Although the focus is on reporting to ClinicalTrials.gov, the approach supports broader application across trial registries and results databases. This paper is intended to stimulate further discussion of this approach among stakeholders, build awareness about the need to improve reporting of MPRPs, and encourage harmonization across trial registries globally.

Database resources of the national center for biotechnology information

The National Center for Biotechnology Information (NCBI) produces a variety of online information resources for biology, including the GenBank® nucleic acid sequence database and the PubMed® database of citations and abstracts published in life science journals. NCBI provides search and retrieval operations for most of these data from 35 distinct databases. The E-utilities serve as the programming interface for the most of these databases. Resources receiving significant updates in the past year include PubMed, PMC, Bookshelf, RefSeq, SRA, Virus, dbSNP, dbVar, ClinicalTrials.gov, MMDB, iCn3D and PubChem. These resources can be accessed through the NCBI home page at https://www.ncbi.nlm.nih.gov.

Characterization of Informed Consent Forms Posted on ClinicalTrials.gov

This cross-sectional study examines available forms and posting trends of registered trials as well as the frequency of form posting by funder type for trials initiated since the revised Common Rule was implemented.

Race and ethnicity reporting for clinical trials in ClinicalTrials.gov and publications

Inclusion and subsequent reporting of minority participants in clinical trials are critical for ensuring external validity and detecting differences among subgroups, however reports suggest that ongoing gaps persist. ClinicalTrials.gov began requiring the reporting of race/ethnicity information (if collected) during results submission for trials in April 2017. For this study, we downloaded and compared trial race/ethnicity information from ClinicalTrials.gov submitted before (N = 3540) and after (N = 3542) the requirement date. We found that 42.0% of pre-requirement trials compared to 91.4% of post-requirement trials reported race/ethnicity information in ClinicalTrials.gov; 8.6% of post-requirement trials indicated race/ethnicity information was not collected. Use of NIH/U.S. Office of Management and Budget (OMB) classification categories was slightly higher in the post-requirement (77.1%) compared to pre-requirement (72.8%) samples. Additionally, we examined two 10% random samples of post-requirement trials - one with customized race/ethnicity reporting in ClinicalTrials.gov and the other with corresponding results publications available in PubMed. In the first random sample, 95.9% of customized categories included race information and 52.7% included ethnicity information. In the other random sample, 33.1% had a corresponding results publication, of which 62.4% reported race/ethnicity information in the publication. Among trials without published race/ethnicity information, 90.0% reported race/ethnicity information on ClinicalTrials.gov. This analysis demonstrates that the requirement has advanced public availability of information on the inclusion of minorities in research, but that further work remains to systematically ensure collection and complete reporting of race/ethnicity information.

Consensus statement on tumour bed localization for radiation after oncoplastic breast surgery

Background

Oncoplastic surgery (ops) is becoming the new standard of care for breast-conserving surgery, leading to some challenges with adjuvant radiation, particularly when accurate tumour bed (tbd) delineation is needed for focused radiation (that is, accelerated partial breast irradiation or boost radiation). Currently, no guidelines have been published concerning tbd localization for adjuvant targeted radiation after ops.

Methods

A modified Delphi method was used to establish consensus by a panel of 20 experts in surgical and radiation oncology at the Canadian Locally Advanced Breast Cancer National Consensus Group and in a subsequent online member survey.

Results

These are the main recommendations:■ Surgical clips are necessary and should, at a minimum, be placed along the 4 side walls of the cavity, plus 1-4 clips at the posterior margin if necessary.■ Operative reports should include pertinent information to help guide the radiation oncologists.■ Breast surgeons and radiation oncologists should have a basic understanding of ops techniques and work on "speaking a common language."■ Careful consideration is needed when determining the value of targeted radiation, such as boost, in higher-level ops procedures with extensive tissue rearrangement.

Conclusions

The panel developed a total of 6 recommendations on tbd delineation for more focused radiation therapy after ops, with more than 80% agreement on each statement. All are summarized, together with the corresponding evidence or expert opinion.

Results Reporting for Trials With the Same Sponsor, Drug, and Condition in ClinicalTrials.gov and Peer-Reviewed Publications

This study examines the extent to which trials registered in ClinicalTrials.gov by individual sponsors for the same drug and condition were available publicly in ClinicalTrials.gov and/or PubMed.

How to avoid common problems when using ClinicalTrials.gov in research: 10 issues to consider

ClinicalTrials.gov, a repository of information about clinical studies and their results, together with specialised search tools, provides a unique window into the clinical research enterprise, which includes all initiated, ongoing, and completed or terminated clinical studies. Researchers are increasingly using information from the database to assess research reporting practices, or to characterise the clinical research enterprise. Conducting valid analyses requires an understanding of both the capabilities and limitations of the database (that is, intrinsic factors) as well as reporting policies and other factors external to the database that influence the types of studies in ClinicalTrials.gov in a specified time. This article discusses 10 key issues that researchers need to consider when using the database to conduct research.

Trialists' Intent to Share Individual Participant Data as Disclosed at ClinicalTrials.gov

This study summarizes responses to trial registration fields on the ClinicalTrials.gov website asking users if they plan to share individual participant data and what information they would be willing to share.

Update on Trial Registration 11 Years after the ICMJE Policy Was Established

In the decade following the journal editors’ trial registration policy, a global trial reporting system (TRS) has arisen to supplement journal publication by increasing the transparency and accountability of the clinical research enterprise (CRE), which ultimately advances evidence-based medicine. Trial registration a foundation component of the TRS. In this article, we assess impact of the trial registration on the CRE with respect to two key goals: (1) establishing a publicly accessible and structured public record of all trials and (2) ensuring access to date-stamped protocol details that change during a study. After characterizing international trial registry landscape, we summarize the published evidence of the impact of the registration laws and policies on the CRE to date. We present three analyses using ClinicalTrials.gov registration data to illustrate approaches for assessing and monitoring the TRS: (1) timing of registration (i.e., prior to trial initiation [prospective] or after trial initiation [retrospective or “late”]; (2) degree of specificity and consistency of registered primary outcome measures compared to descriptions in study protocols and published articles; and (3) a survey of the published literature to characterize how ClinicalTrials.gov data has been used in research on the CRE. These findings suggest that, while the TRS is largely moving towards goals, key stakeholders need to do more in the next decade.

ClinicalTrials.gov and Drugs@FDA: A Comparison of Results Reporting for New Drug Approval Trials

BACKGROUND

Pharmaceutical companies and other trial sponsors must submit certain trial results to ClinicalTrials.gov. The validity of these results is unclear.

PURPOSE

To validate results posted on ClinicalTrials.gov against publicly available U.S. Food and Drug Administration (FDA) reviews on Drugs@FDA.

DATA SOURCES

ClinicalTrials.gov (registry and results database) and Drugs@FDA (medical and statistical reviews).

STUDY SELECTION

100 parallel-group, randomized trials for new drug approvals (January 2013 to July 2014) with results posted on ClinicalTrials.gov (15 March 2015).

DATA EXTRACTION

2 assessors extracted, and another verified, the trial design, primary and secondary outcomes, adverse events, and deaths.

RESULTS

Most trials were phase 3 (90%), double-blind (92%), and placebo-controlled (73%) and involved 32 drugs from 24 companies. Of 137 primary outcomes identified from ClinicalTrials.gov, 134 (98%) had corresponding data at Drugs@FDA, 130 (95%) had concordant definitions, and 107 (78%) had concordant results. Most differences were nominal (that is, relative difference <10%). Primary outcome results in 14 trials could not be validated. Of 1927 secondary outcomes from ClinicalTrials.gov, Drugs@FDA mentioned 1061 (55%) and included results data for 367 (19%). Of 96 trials with 1 or more serious adverse events in either source, 14 could be compared and 7 had discordant numbers of persons experiencing the adverse events. Of 62 trials with 1 or more deaths in either source, 25 could be compared and 17 were discordant.

LIMITATION

Unknown generalizability to uncontrolled or crossover trial results.

CONCLUSION

Primary outcome definitions and results were largely concordant between ClinicalTrials.gov and Drugs@FDA. Half the secondary outcomes, as well as serious events and deaths, could not be validated because Drugs@FDA includes only "key outcomes" for regulatory decision making and frequently includes only adverse event results aggregated across multiple trials.

PRIMARY FUNDING SOURCE

National Library of Medicine.

Terminated Trials in the ClinicalTrials.gov Results Database: Evaluation of Availability of Primary Outcome Data and Reasons for Termination

Background

Clinical trials that end prematurely (or “terminate”) raise financial, ethical, and scientific concerns. The extent to which the results of such trials are disseminated and the reasons for termination have not been well characterized.

Methods and Findings

A cross-sectional, descriptive study of terminated clinical trials posted on the ClinicalTrials.gov results database as of February 2013 was conducted. The main outcomes were to characterize the availability of primary outcome data on ClinicalTrials.gov and in the published literature and to identify the reasons for trial termination. Approximately 12% of trials with results posted on the ClinicalTrials.gov results database (905/7,646) were terminated. Most trials were terminated for reasons other than accumulated data from the trial (68%; 619/905), with an insufficient rate of accrual being the lead reason for termination among these trials (57%; 350/619). Of the remaining trials, 21% (193/905) were terminated based on data from the trial (findings of efficacy or toxicity) and 10% (93/905) did not specify a reason. Overall, data for a primary outcome measure were available on ClinicalTrials.gov and in the published literature for 72% (648/905) and 22% (198/905) of trials, respectively. Primary outcome data were reported on the ClinicalTrials.gov results database and in the published literature more frequently (91% and 46%, respectively) when the decision to terminate was based on data from the trial.

Conclusions

Trials terminate for a variety of reasons, not all of which reflect failures in the process or an inability to achieve the intended goals. Primary outcome data were reported most often when termination was based on data from the trial. Further research is needed to identify best practices for disseminating the experience and data resulting from terminated trials in order to help ensure maximal societal benefit from the investments of trial participants and others involved with the study.

Publication of NIH funded trials registered in ClinicalTrials.gov: cross sectional analysis

OBJECTIVE

To review patterns of publication of clinical trials funded by US National Institutes of Health (NIH) in peer reviewed biomedical journals indexed by Medline.

DESIGN

Cross sectional analysis.

SETTING

Clinical trials funded by NIH and registered within ClinicalTrials.gov (clinicaltrials.gov), a trial registry and results database maintained by the US National Library of Medicine, after 30 September 2005 and updated as having been completed by 31 December 2008, allowing at least 30 months for publication after completion of the trial.

MAIN OUTCOME MEASURES

Publication and time to publication in the biomedical literature, as determined through Medline searches, the last of which was performed in June 2011.

RESULTS

Among 635 clinical trials completed by 31 December 2008, 294 (46%) were published in a peer reviewed biomedical journal, indexed by Medline, within 30 months of trial completion. The median period of follow-up after trial completion was 51 months (25th-75th centiles 40-68 months), and 432 (68%) were published overall. Among published trials, the median time to publication was 23 months (14-36 months). Trials completed in either 2007 or 2008 were more likely to be published within 30 months of study completion compared with trials completed before 2007 (54% (196/366) v 36% (98/269); P<0.001).

CONCLUSIONS

Despite recent improvement in timely publication, fewer than half of trials funded by NIH are published in a peer reviewed biomedical journal indexed by Medline within 30 months of trial completion. Moreover, after a median of 51 months after trial completion, a third of trials remained unpublished.

The ClinicalTrials.gov results database--update and key issues

BACKGROUND

The ClinicalTrials.gov trial registry was expanded in 2008 to include a database for reporting summary results. We summarize the structure and contents of the results database, provide an update of relevant policies, and show how the data can be used to gain insight into the state of clinical research.

METHODS

We analyzed ClinicalTrials.gov data that were publicly available between September 2009 and September 2010.

RESULTS

As of September 27, 2010, ClinicalTrials.gov received approximately 330 new and 2000 revised registrations each week, along with 30 new and 80 revised results submissions. We characterized the 79,413 registry and 2178 results of trial records available as of September 2010. From a sample cohort of results records, 78 of 150 (52%) had associated publications within 2 years after posting. Of results records available publicly, 20% reported more than two primary outcome measures and 5% reported more than five. Of a sample of 100 registry record outcome measures, 61% lacked specificity in describing the metric used in the planned analysis. In a sample of 700 results records, the mean number of different analysis populations per study group was 2.5 (median, 1; range, 1 to 25). Of these trials, 24% reported results for 90% or less of their participants.

CONCLUSIONS

ClinicalTrials.gov provides access to study results not otherwise available to the public. Although the database allows examination of various aspects of ongoing and completed clinical trials, its ultimate usefulness depends on the research community to submit accurate, informative data.

Estimating consumer familiarity with health terminology: a context-based approach

OBJECTIVES

Effective health communication is often hindered by a "vocabulary gap" between language familiar to consumers and jargon used in medical practice and research. To present health information to consumers in a comprehensible fashion, we need to develop a mechanism to quantify health terms as being more likely or less likely to be understood by typical members of the lay public. Prior research has used approaches including syllable count, easy word list, and frequency count, all of which have significant limitations.

DESIGN

In this article, we present a new method that predicts consumer familiarity using contextual information. The method was applied to a large query log data set and validated using results from two previously conducted consumer surveys.

MEASUREMENTS

We measured the correlation between the survey result and the context-based prediction, syllable count, frequency count, and log normalized frequency count.

RESULTS

The correlation coefficient between the context-based prediction and the survey result was 0.773 (p < 0.001), which was higher than the correlation coefficients between the survey result and the syllable count, frequency count, and log normalized frequency count (p < or = 0.012).

CONCLUSIONS

The context-based approach provides a good alternative to the existing term familiarity assessment methods.