Dataset Information

Publication proportions for registered breast cancer trials: before and following the introduction of the ClinicalTrials.gov results database.

ABSTRACT: To limit selective and incomplete publication of the results of clinical trials, registries including ClinicalTrials.gov were introduced. The ClinicalTrials.gov registry added a results database in 2008 to enable researchers to post the results of their trials as stipulated by the Food and Drug Administration Amendment Act of 2007. This study aimed to determine the direction and magnitude of any change in publication proportions of registered breast cancer trials that occurred since the inception of the ClinicalTrials.gov results database.A cross-sectional study design was employed using ClinicalTrials.gov, a publicly available registry/results database as the primary data source. Registry contents under the subcategories 'Breast Neoplasms' and 'Breast Neoplasms, Male' were downloaded on 1 August 2015. A literature search for included trials was afterwards conducted using MEDLINE and DISCOVER databases to determine publication status of the registered breast cancer trials.Nearly half (168/340) of the listed trials had been published, with a median time to publication of 24 months (Q1?=?14 months, Q3?=?42 months). Only 86 trials were published within 24 months of completion. There was no significant increase in publication proportions of trials that were completed before the introduction of the results database compared to those completed after (OR?=?1.00, 95 % CI?=?.61 to 1.63; adjusted OR?=?0.84, 95 % CI?=?.51 to 1.39). Characteristics associated with publication included trial type (observational versus interventional adjusted OR?=?.28, 95 % CI?=?.10 to .74) and completion/termination status (terminated versus completed adjusted OR?=?.22, 95 % CI?=?.09 to .51).Less than a half of breast cancer trials registered in ClinicalTrials.gov are published in peer-reviewed journals.

SUBMITTER: Asiimwe IG

PROVIDER: S-EPMC5803577 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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Publication proportions for registered breast cancer trials: before and following the introduction of the ClinicalTrials.gov results database.

Asiimwe Innocent Gerald IG Rumona Dickson D

Research integrity and peer review 20160718

<h4>Background</h4>To limit selective and incomplete publication of the results of clinical trials, registries including ClinicalTrials.gov were introduced. The ClinicalTrials.gov registry added a results database in 2008 to enable researchers to post the results of their trials as stipulated by the Food and Drug Administration Amendment Act of 2007. This study aimed to determine the direction and magnitude of any change in publication proportions of registered breast cancer trials that occurred ...[more]

PMID: 29451530

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Project description:ImportanceThe published evidence in support of probiotic use is conflicting, which may be a result of selective publication of probiotic trials.ObjectivesTo compare the proportion of registered trials that evaluate pediatric probiotics vs those that evaluate antibiotics that are published and to identify study-related factors associated with publication status.Design, setting, and participantsThis cross-sectional study evaluated eligible trials registered in ClinicalTrials.gov, an online clinical trials registry, from July 1, 2005, to June 30, 2016. Eligible studies included participants younger than 18 years, evaluated a probiotic or 1 of the 5 most commonly prescribed antibiotics in children and adolescents, and randomized study participants. All searches were updated and finalized as of September 9, 2020.ExposuresProbiotic or antibiotic.Main outcomes and measuresThe primary outcome was study publication status. In addition, exposure status (probiotic vs antibiotic), trial result, and funding source were assessed for independent association with publication status. Whether study design elements, publication journal impact factor, and the interval from study completion to publication differed by exposure status were also evaluated.ResultsA total of 401 unique trials (265 probiotic and 136 antibiotic) met eligibility criteria. A greater proportion of antibiotic compared with probiotic studies were published (83 [61.0%] vs 119 [44.9%]; difference, 16.1% [95% CI, 5.8%-25.9%]). After adjustment for funding source, blinding, and purpose, studies evaluating an antibiotic were more likely to be published (odds ratio, 2.1 [95% CI, 1.3-3.4]). No other covariates included in the model were independently associated with publication status. Antibiotic trials, compared with probiotic trials, were more likely to have a therapeutic purpose (114 [83.8%] vs 117 [44.2%]; difference, 39.6% [95% CI, 31.1%-48.3%]) and to be multicenter (46 [33.8%] vs 46 [17.4%]; difference, 16.5% [95% CI, 7.5%-25.7%]). The median impact factor of the journals in which the studies were published was higher for the antibiotic trials (7.2 [IQR, 2.8-20.5] vs 3.0 [IQR, 2.3-4.2]; P < .001). The median number of days to publication did not differ between the probiotic and antibiotic trials (683 [IQR, 441-1036] vs 801 [IQR, 550-1183]; P = .24).Conclusions and relevanceThe findings of this cross-sectional study suggest that probiotic studies are less likely to be published than antibiotic trials. No other study characteristics were associated with publication status. This finding raises concerns regarding the results of meta-analyses of probiotic trials.

Project description:ImportancePublishing study protocols might reduce research waste because of unclear methods or incomplete reporting; on the other hand, there might be few additional benefits of publishing protocols for registered trials that are never completed or published. No study has investigated the proportion of published protocols associated with published results.ObjectiveTo estimate the proportion of published trial protocols for which there are not associated published results.Design, setting, and participantsThis cross-sectional study used stratified random sampling to identify registered clinical trials with protocols published between January 2011 and August 2022 and indexed in PubMed Central. Ongoing studies and those within 1 year of the primary completion date on ClinicalTrials.gov were excluded. Published results were sought from August 2022 to March 2023 by searching ClinicalTrials.gov, emailing authors, and using an automated tool, as well as through incidental discovery.Main outcomes and measuresThe primary outcome was a weighted estimate of the proportion of registered trials with published protocols that also had published main results. The proportion of trials with unpublished results was estimated using a weighted mean.ResultsFrom 1500 citations that were screened, 308 clinical trial protocols were included, and it was found that 87 trials had not published their main results. Most included trials were investigator-initiated evaluations of nonregulated products. When published, results appeared a mean (SD) of 3.4 (2.0) years after protocol publications. With the use of a weighted mean, an estimated 4754 (95% CI, 4296-5226) eligible clinical trial protocols were published and indexed in PubMed Central between 2011 and 2022. In the weighted analysis, 1708 of those protocols (36%; 95% CI, 31%-41%) were not associated with publication of main results. In a sensitivity analysis excluding protocols published after 2019, an estimated 25% (95% CI, 20%-30%) of 3670 (95% CI, 3310-4032) protocol publications were not associated with publication of main results.Conclusions and relevanceThis cross-sectional study of clinical trial protocols published on PubMed Central between 2011 and 2022 suggests that many protocols were not associated with subsequent publication of results. The overall benefits of publishing study protocols might outweigh the research waste caused by unnecessary protocol publications.

Project description:BackgroundThe $1.1 billion investment in comparative effectiveness research will reshape the evidence-base supporting decisions about treatment effectiveness, safety, and cost. Defining the current prevalence and characteristics of comparative effectiveness (CE) research will enable future assessments of the impact of this program.MethodsWe conducted an observational study of clinical trials addressing priority research topics defined by the Institute of Medicine and conducted in the US between 2007 and 2010. Trials were identified in ClinicalTrials.gov. Main outcome measures were the prevalence of comparative effectiveness research, nature of comparators selected, funding sources, and impact of these factors on results.Results231 (22.3%; 95% CI 19.8%-24.9%) studies were CE studies and 804 (77.7%; 95% CI, 75.1%-80.2%) were non-CE studies, with 379 (36.6%; 95% CI, 33.7%-39.6%) employing a placebo control and 425 (41.1%; 95% CI, 38.1%-44.1%) no control. The most common treatments examined in CE studies were drug interventions (37.2%), behavioral interventions (28.6%), and procedures (15.6%). Study findings were favorable for the experimental treatment in 34.8% of CE studies and greater than twice as many (78.6%) non-CE studies (P<0.001). CE studies were more likely to receive government funding (P?=?0.003) and less likely to receive industry funding (P?=?0.01), with 71.8% of CE studies primarily funded by a noncommercial source. The types of interventions studied differed based on funding source, with 95.4% of industry trials studying a drug or device. In addition, industry-funded CE studies were associated with the fewest pediatric subjects (P<0.001), the largest anticipated sample size (P<0.001), and the shortest study duration (P<0.001).ConclusionsIn this sample of studies examining high priority areas for CE research, less than a quarter are CE studies and the majority is supported by government and nonprofits. The low prevalence of CE research exists across CE studies with a broad array of interventions and characteristics.

Project description:BackgroundData monitoring committees advise on clinical trial conduct through appraisal of emerging data to ensure participant safety and scientific integrity. While consideration of their use is recommended for trials performed with vulnerable populations, previous research has shown that data monitoring committees are reported infrequently in publications of pediatric randomized controlled trials. We aimed to assess the frequency of reported data monitoring committee adoption in ClinicalTrials.gov registry records and to examine the influence of key trial characteristics.MethodsWe conducted a cross-sectional data analysis of all randomized controlled trials performed exclusively in a pediatric population and registered in ClinicalTrials.gov between 2008 and 2021. We used the Access to Aggregate Content of ClinicalTrials.gov database to retrieve publicly available information on trial characteristics and data on safety results. Abstracted data included reported trial design and conduct parameters, population and intervention characteristics, reasons for prematurely halting, serious adverse events, and mortality outcomes. We performed descriptive analyses on the collected data and explored the influence of clinical, methodological, and operational trial characteristics on the reported adoption of data monitoring committees.ResultsWe identified 13,928 pediatric randomized controlled trial records, of which 39.7% reported adopting a data monitoring committee, 49.0% reported not adopting a data monitoring committee, and 11.3% did not answer on this item. While the number of registered pediatric trials has been increasing since 2008, we found no clear time trend in the reported adoption of data monitoring committees. Data monitoring committees were more common in multicenter trials (50.6% vs 36.9% for single-center), multinational trials (60.2% vs 38.7% for single-country), National Institutes of Health-funded (60.3% vs 40.1% for industry-funded or 37.5% for other funders), and placebo-controlled (47.6% vs 37.5% for other types of control groups). Data monitoring committees were also more common among trials enrolling younger participants, trials employing blinding techniques, and larger trials. Data monitoring committees were more common in trials with at least one serious adverse event (52.6% vs 38.4% for those without) as well as for trials with reported deaths (70.3% vs 38.9% for trials without reported deaths). In all, 4.9% were listed as halted prematurely, most often due to low accrual rates. Trials with a data monitoring committee were more often halted for reasons related to scientific data than trials without a data monitoring committee (15.7% vs 7.3%).ConclusionAccording to registry records, the use of data monitoring committees in pediatric randomized controlled trials was more frequent than previously reported in reviews of published trial reports. The use of data monitoring committees varied across key clinical and trial characteristics based on which their use is recommended. Data monitoring committees may still be underutilized in pediatric trials, and reporting of this item could be improved.

Project description:Objective: This study aimed to analyze the characteristics and reasons of early discontinuation of obsessive-compulsive disorder (OCD) trials registered on ClinicalTrials.gov. Methods: OCD trials and relevant publications were searched on ClinicalTrials.gov and PubMed, respectively. The characteristics and details regarding the timely publication of trials were recorded. Cox regression analysis was used to explore factors associated with the early discontinuation of OCD trials. Results: The analysis included 298 OCD therapy trials. Most investigations recruited <100 patients and were more likely to involve adults. Of all OCD studies identified, 67.8% were randomized and 61.4% were blind (single- or double-blind). Universities and hospitals were recorded as the two primary locations in the majority of trials. A total of 155 trials (52%) were completed; however, only 29% of those were published. Of the published trials, >70% were published at least 1 year after completion. Behavioral therapy trials were the most common type of major treatment-aimed OCD trials (39%), followed by drug trials (35.1%) and device/procedure trials (24.7%). The univariate Cox regression analysis indicated that drug trials [hazard ratio (HR) = 2.56, 95% confidence interval (CI): 1.21-5.43], absence of collaborators (HR = 3.87, 95% CI: 1.62-9.26), and sponsorship by industry (HR = 3.97, 95% CI: 1.49-10.53) were risk factors for early discontinuation of OCD trials. Further multivariate Cox regression showed that drug trials (HR = 3.93, 95% CI: 1.71-9.08) and absence of collaborators (HR = 5.17, 95% CI: 1.97-13.54) were independent risk factors for early trial discontinuation of OCD trials. The sensitivity analysis confirmed these results. Non-drug trials (OR = 3.32, 95% CI: 1.21-9.11), absence of collaborators (OR = 3.25, 95% CI: 1.10-9.60), and non-blinded trials (OR = 5.23, 95% CI: 1.05-26.2) were independent risk factors for unreported results in registry. Conclusion: The diagnosis and prevention of OCD are rarely investigated in trials. Underreporting and delayed reporting remain major problems. The type of intervention and participation of collaborators are associated with early discontinuation of OCD trials.

Dataset Information

Publication proportions for registered breast cancer trials: before and following the introduction of the ClinicalTrials.gov results database.

Publications

Publication proportions for registered breast cancer trials: before and following the introduction of the ClinicalTrials.gov results database.

Similar Datasets

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