Clinical trial design and dissemination: comprehensive analysis of clinicaltrials.gov and PubMed data since 2005

Tracing Digital Therapeutics Research Across Medical Specialties: Evidence from ClinicalTrials.gov

Digital therapeutics (DTx), evidence-based software interventions for preventing, managing, or treating medical disorders, have rapidly evolved with healthcare's shift toward online, patient-centric solutions. This study scrutinizes DTx clinical trials from 2005 to 2022, analyzing their growth, funding, underlying medical specialties, and other R&D characteristics, using ClinicalTrials.gov data. Our analysis includes trials categorized via the ICD-11 system, covering active, recruiting, or completed studies and considering trials listing multiple conditions. In analyzing 5,889 registered DTx trials, we document a more than five-fold increase in such trials since 2011, and a compound annual growth rate of 22.82% since 2005. While most trials were single-center, the median number of study subjects increased in recent years, driven by larger interventional trials. The key disciplines driving this growth were psychiatry, neurology, oncology, and endocrinology. Mental health dominated DTx trials in recent years, led by neurocognitive disorders, substance abuse disorders, and mood disorders. Industry funding varied across disciplines and was particularly high in visual system diseases and dermatology. DTx trials have surged since 2005, accelerated by recent growth in mental health trials. These trends mirror developments toward remote healthcare delivery, amplified by digital health investments during the COVID-19 pandemic. Growing numbers of participants in DTx trials point to increased demand for more robust trials. However, because most trials are single-center and country-specific, more international cooperation and harmonized evaluation standards will be essential for DTx trials to become more efficient and provide validation across countries, health systems, and groups of individuals.

Transgender people in clinical trials of drugs and biologics: An analysis of ClinicalTrials.gov from 2007 to 2023

AIMS

Transgender people have unmet health needs related to chronic conditions such as dementia, osteoporosis and hypertension. Community-driven advocacy increased transgender representation in phase III trials for pharmacological prevention of HIV, but the extent to which drug trials for other conditions have included transgender people is unknown. We investigated the extent to which trials of drugs and biologics represented transgender people across therapeutic areas on ClinicalTrials.gov.

METHODS

Cross-sectional analysis of trials of drugs and biologics registered on ClinicalTrials.gov from 2007-2023. We included efficacy and effectiveness trials (phase II-IV) with transgender-related terms (e.g. 'transgend*'). We labelled trials as Inclusive or Exclusive of transgender people using the trial eligibility criteria. We compared trials (therapeutic area, trial design, enrolment), summarized trials registered from 2008 onward and characterized participant enrolment for Inclusive trials with primary trial publications. We summarized continuous data using median (range), categorical data using frequencies and percentages and compared trial characteristics using Fisher's exact test.

RESULTS

Ninety-seven trials represented transgender people. Characteristics were similar between 85 Inclusive and 12 Exclusive trials. Among Inclusive trials, 58% focused on infectious diseases (e.g. treatment or prevention of HIV and COVID-19), 15% on mental health (e.g. post-traumatic stress disorder, substance use-related disorders), and the remainder focused on endocrine (9%), pain (5%), digestive system disorders (1%) and neoplasms (1%). Twenty (of 25) trials reported enrolment of transgender participants in primary trial publications or reported results.

CONCLUSION

Transgender-inclusive trials have increased since 2008. Most trials focused on infectious diseases and mental health. Investigators should increase opportunities to include of transgender people in trials of drugs and biologics for chronic diseases.

Should informed consent and information related to patient recruitment in clinical trials be available to the reader of scientific articles? A case study in dentistry

Ethical aspects in research should be transparently reported. This study aimed to investigate whether informed consent and information related to patient recruitment in clinical studies are well reported in the scientific literature. Randomized clinical trials (RCTs) on root coverage procedures published between November 2016 and November 2021 were selected from the PubMed database. Items/questions were used to guide the extraction of data related to patient recruitment, with a focus on the detailed report of informed consent used to clarify the research to the patient. Data were extracted from the published article and the respective research protocol published in a public registry. Information related to potential selective outcome reporting (SOR) was also extracted. In total, 187 documents were initially screened and 74 reports of RCTs were included. No informed consent was published in the article. Only one research protocol provided a link to the informed consent. Deviations from reporting in the research protocol and published article were found, suggesting SOR. Informed consent and information related to patient recruitment in RCTs on root covering procedures are severely underreported. The present findings may stimulate further discussion and debate on the need for making this information publicly available.

Poor Result Reporting Rate in Cell Therapy Trials Registered at ClinicalTrials.gov

As research associates in clinical experiments, we have an obligation to disclose clinical methodologies and findings in full transparency in ethics. However, inadequate disclosure in results reporting clinical trials registered on ClinicalTrials.gov has been revealed, with approximately half the trial results not being reported in an applicable manner. Our recent study in clinical trials of regenerative medicine for four kinds of neurological diseases revealed that the rate of result reporting to ClinicalTrials.gov is inadequate for gene and cell therapy (CT) trials. In this path, further curiosity emerged to see what the findings would be if the analysis was conducted for trials in all disease areas, and outcomes if gene therapy (GT) and CT were distinguished in terms. In this study, the scope of analysis was further expanded to include all disease areas, and the drug classification from the AdisInsight database was used for modality classification, with biologic drug trials classified as controls, CT, ex vivo GT, and in vivo GT. To begin, among all interventional clinical trials with registration in the ClinicalTrials.gov registry and with a primary completion between 2010 and 2019, we created a total of 5539 datasets corresponding to trials classified as GT and CT, while biologics (BLG) as controls in the AdisInsight drug classification. The status of reported results of these trials was identified by surveying posting status of ClinicalTrials.gov and publication in journals (PubMed), respectively. Based on the obtained dataset, multivariate analysis was performed on the data on the reporting rate of clinical trial results, aggregated by sponsor, phase, status, and modality (CT, ex vivo GT, in vivo GT, and BLG), respectively. The result shows that CT was identified as an independent factor restraining result reporting ratio in both ClinicalTrials.gov and total disclosures, whereas ex vivo GT as boosting result reporting ratio. Since the result reporting rate of CT results was notably poor, we discussed the causes and solutions in this regard.

Industry Involvement and Transparency in the Most Cited Clinical Trials, 2019-2022

Importance

Industry involvement is prominent in influential clinical trials, and commitments to transparency of trials are highly variable.

Objective

To evaluate the modes of industry involvement and the transparency features of the most cited recent clinical trials across medicine.

Design, Setting, and Participants

This cross-sectional study was a meta-research assessment including randomized and nonrandomized clinical trials published in 2019 or later. The 600 trials of any type of disease or setting that attracted highest number of citations in Scopus as of December 2022 were selected for analysis. Data were analyzed from March to September 2023.

Main Outcomes and Measures

Outcomes of interest were industry involvement (sponsor, author, and analyst) and transparency (protocols, statistical analysis plans, and data and code availability).

Results

Among 600 trials with a median (IQR) sample size of 415 (124-1046) participants assessed, 409 (68.2%) had industry funding and 303 (50.5%) were exclusively industry-funded. A total of 354 trials (59.0%) had industry authors, with 280 trials (46.6%) involving industry analysts and 125 trials (20.8%) analyzed exclusively by industry analysts. Among industry-funded trials, 364 (89.0%) reached conclusions favoring the sponsor. Most trials (478 trials [79.7%]) provided a data availability statement, and most indicated intention to share the data, but only 16 trials (2.7%) had data already readily available to others. More than three-quarters of trials had full protocols (482 trials [82.0%]) or statistical analysis plans (446 trials [74.3%]) available, but only 27 trials (4.5%) explicitly mentioned sharing analysis code (8 readily available; 19 on request). Randomized trials were more likely than nonrandomized studies to involve only industry analysts (107 trials [22.9%] vs 18 trials [13.6%]; P = .02) and to have full protocols (405 studies [86.5%] vs 87 studies [65.9%]; P < .001) and statistical analysis plans (373 studies [79.7%] vs 73 studies [55.3%]; P < .001) available. Almost all nonrandomized industry-funded studies (90 of 92 studies [97.8%]) favored the sponsor. Among industry-funded trials, exclusive industry funding (odds ratio, 2.9; 95% CI, 1.5-5.4) and industry-affiliated authors (odds ratio, 2.9; 95% CI, 1.5-5.6) were associated with favorable conclusions for the sponsor.

Conclusions and Relevance

This cross-sectional study illustrates how industry involvement in the most influential clinical trials was prominent not only for funding, but also authorship and provision of analysts and was associated with conclusions favoring the sponsor. While most influential trials reported that they planned to share data and make both protocols and statistical analysis plans available, raw data and code were rarely readily available.

Chinese Clinical Trial Registry 13-year data collection and analysis: geographic distribution, financial support, research phase, duration, and disease categories

Objective

To evaluate the current status of trial registration on the Chinese Clinical Trial Registry (ChiCTR).

Design

In this descriptive study, a multi-dimensional grouping analysis was conducted to estimate trends in the annual trial registration, geographical distribution, sources of funding, targeted diseases, and trial subtypes.

Setting

We have analyzed all clinical trial records (over 30,000) registered on the Chinese Clinical Trial Registry (ChiCTR) from 2007 to 2020 executed in China.

Main outcomes and measures

The main outcome was the baseline characteristics of registered trials. These trials were categorized and analyzed based on geographical distribution, year of implementation, disease type, resource and funding type, trial duration, trial phase, and the type of experimental approach.

Results

From 2008 to 2017, a consistent upward trend in clinical trial registrations was observed, showing an average annual growth rate of 29.2%. The most significant year-on-year (yoy%) growth in registrations occurred in 2014 (62%) and 2018 (68.5%). Public funding represented the predominant source of funding in the Chinese healthcare system. The top five ChiCTR registration sites for all disease types were highly populated urban regions of China, including Shanghai (5,658 trials, 18%), Beijing (5,127 trials, 16%), Guangdong (3,612 trials, 11%), Sichuan (2,448 trials, 8%), and Jiangsu (2,196 trials, 7%). Trials targeting neoplastic diseases accounted for the largest portion of registrations, followed by cardio/cerebrovascular disease (CCVD) and orthopedic diseases-related trials. The largest proportions of registration trial duration were 1-2 years, less than 1 year, and 2-3 years (at 27.36, 26.71, and 22.46%). In the case of the research phase, the top three types of all the registered trials are exploratory research, post-marketing drugs, and clinical trials of new therapeutic technology.

Conclusion and relevance

Oncological and cardiovascular diseases receive the highest share of national public funding for medical clinical trial-based research in China. Publicly funded trials represent a major segment of the ChiCTR registry, indicating the dominating role of public governance in this health research sector. Furthermore, the growing number of analyzed records reflect the escalation of clinical research activities in China. The tendency to distribute funding resources toward exceedingly populated areas with the highest incidence of oncological and cardiovascular diseases reveals an aim to reduce the dominating disease burden in the urban conglomerates in China.

A critical analysis of neuro-oncology clinical trials

BACKGROUND

Limitations in trial design, accrual, and data reporting impact efficient and reliable drug evaluation in cancer clinical trials. These concerns have been recognized in neuro-oncology but have not been comprehensively evaluated. We conducted a semi-automated survey of adult interventional neuro-oncology trials, examining design, interventions, outcomes, and data availability trends.

METHODS

Trials were selected programmatically from ClinicalTrials.gov using primary malignant central nervous system tumor classification terms. Regression analyses assessed design and accrual trends; effect size analysis utilized survival rates among trials investigating survival.

RESULTS

Of 3038 reviewed trials, most trials reporting relevant information were nonblinded (92%), single group (65%), nonrandomized (51%), and studied glioblastomas (47%) or other gliomas. Basic design elements were reported by most trials, with reporting increasing over time (OR = 1.24, P < .00001). Trials assessing survival outcomes were estimated to assume large effect sizes of interventions when powering their designs. Forty-two percent of trials were completed; of these, 38% failed to meet their enrollment target, with worse accrual over time (R = -0.94, P < .00001) and for US versus non-US based trials (OR = 0.5, P < .00001). Twenty-eight percent of completed trials reported partial results, with greater reporting for US (34.6%) versus non-US based trials (9.3%, P < .00001). Efficacy signals were detected by 15%-23% of completed trials reporting survival outcomes.

CONCLUSION

Low randomization rates, underutilization of controls, and overestimation of effect size, particularly pronounced in early-phase trials, impede generalizability of results. Suboptimal designs may be driven by accrual challenges, underscoring the need for cooperative efforts and novel designs. The limited results reporting highlights the need to incentivize data reporting and harmonization.

Uncovering key clinical trial features influencing recruitment

Background

Randomized clinical trials (RCT) are the foundation for medical advances, but participant recruitment remains a persistent barrier to their success. This retrospective data analysis aims to (1) identify clinical trial features associated with successful participant recruitment measured by accrual percentage and (2) compare the characteristics of the RCTs by assessing the most and least successful recruitment, which are indicated by varying thresholds of accrual percentage such as ≥ 90% vs ≤ 10%, ≥ 80% vs ≤ 20%, and ≥ 70% vs ≤ 30%.

Methods

Data from the internal research registry at Columbia University Irving Medical Center and Aggregated Analysis of ClinicalTrials.gov were collected for 393 randomized interventional treatment studies closed to further enrollment. We compared two regularized linear regression and six tree-based machine learning models for accrual percentage (i.e., reported accrual to date divided by the target accrual) prediction. The outperforming model and Tree SHapley Additive exPlanations were used for feature importance analysis for participant recruitment. The identified features were compared between the two subgroups.

Results

CatBoost regressor outperformed the others. Key features positively associated with recruitment success, as measured by accrual percentage, include government funding and compensation. Meanwhile, cancer research and non-conventional recruitment methods (e.g., websites) are negatively associated with recruitment success. Statistically significant subgroup differences (corrected p-value < .05) were found in 15 of the top 30 most important features.

Conclusion

This multi-source retrospective study highlighted key features influencing RCT participant recruitment, offering actionable steps for improvement, including flexible recruitment infrastructure and appropriate participant compensation.

A Pilot Study on Result Reporting Rates from Clinical Trials of Regenerative Medicine

Sharing the methods and results of clinical trials with full transparency is an ethical obligation for those involved in clinical research. In this regard, ClinicalTrials.gov requires reporting of results to the registry within 1 year of completion of the trial. However, a poor result reporting rate has been pointed out, with approximately half the trial results not been reported. It has been suggested that one of the reasons behind this could be the influence of sponsors who conduct the clinical trials. In the course of our previous trend analysis on regenerative medicine for stroke (STR) using ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) portal site as data sources, we suspected whether the results of gene and/or cell therapy trials are poorly reported. For this reason, a multivariate analysis using data from ClinicalTrials.gov was performed to identify the factors suppressing the result reporting rate, expanding our study to four different kinds of neurological diseases and regenerative medicine as a treatment modality when small-molecule compounds and biologics were set up as controls, in addition to the sponsor type factor. As a result, we found gene and/or cell therapy (therapeutic modality) in addition to STR (disease area), trials completed in 2005-2007, and clinical phases II and IV as independent factors that suppressed the rate of reporting results to ClinicalTrials.gov. On the other hand, big pharmaceutical companies were identified as a factor that increased the reporting result rate to ClinicalTrials.gov. When we applied result reporting publications through PubMed as an index, our study data revealed that the following factors were not identified as the cause for a decrease in the reporting result rate: STR (as disease area), trials completed between 2005 and 2007, and gene/cell therapy (as treatment modality). In this context, our findings indicate that gene/cell therapy has led to the suppression of the result reporting rate to ClinicalTrials.gov. This confirmed our initial suspicion of the low result reporting rate of gene/cell therapy trials. We believe that further studies are required to elucidate the factors affecting the result reporting rate from the perspective of disease area and treatment modality. Impact Statement Several studies have addressed the poor result reporting rate of clinical trials, which still remains an issue. Regenerative medicine holds great promise for the future and the process of its practical application is expected to be challenging. Although having a limited disease area and small sample size, to the best of our knowledge, this is the first study to point out insufficient result reporting of clinical trials of regenerative medicine from the perspective of treatment modality. This report highlights an issue for discussing the path toward its translation through an overview of various factors in comparison with conventional treatment modalities.

Clinical Trials in Hypertrophic Cardiomyopathy Therapy: A Comprehensive Analysis of Trials Registered in Global Clinical Databases

Background

With the disappointing results associated with the use of cardiac myosin inhibitors in the treatment of hypertrophic cardiomyopathy (HCM), the development of new therapies in clinical trials for HCM has rapidly increased. We assessed the characteristics of therapeutic intervention in HCM registered on ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP).

Methods

We conducted a cross-sectional, descriptive study of clinical trials for therapeutic intervention in HCM registered on ClinicalTrials.gov and ICTRP.

Results

This study analyzed 137 registered trials. Regarding study designs of these trials, 77.37% were purpose of treatment, 59.12% were randomized, 50.36% were parallel assignment, 45.26% were performed with masking, 48.18% recruited less than 50 participants, and 27.74% were Phase 2 trials. In total, 67 trials were new drug trials, of which 35 drugs were tested in these trials, and 13 trials involved treatment with mavacamten. Of these 67 clinical drug trials, 44.78% of trials involved the study of amines, and 16.42% involved 1-ring heterocyclic compounds. Regarding the NCI Thesaurus Tree, 23.81% of trials involved myosin inhibitors, 23.81% of trials involved drugs belonging to agents affecting the cardiovascular system, and 20.63% were involved in testing cation channel blockers. The drug-target network showed that myosin-7, potassium voltage-gated channel subfamily h member 2, beta-1 adrenergic receptor, carnitine o-palmitoyltransferase 1, and liver isoform were the most targeted pathways of the clinical trials analyzed in the drug-target network.

Conclusion

The number of clinical trials investigating therapeutic interventions for HCM has increased in recent years. Ultimately, recent HCM therapeutic clinical trials generally did not incorporate either randomized controlled trials or masking and were small studies recruiting fewer than 50 participants. Although recent research has focused on targeting myosin-7, the molecular signaling mechanisms involved in the pathogenesis of HCM have the potential to elucidate novel target pathways.

Principal Investigators' Perceptions on Factors Associated with Successful Recruitment in Clinical Trials

Participant recruitment continues to be a challenge to the success of randomized controlled trials, resulting in increased costs, extended trial timelines and delayed treatment availability. Literature provides evidence that study design features (e.g., trial phase, study site involvement) and trial sponsor are significantly associated with recruitment success. Principal investigators oversee the conduct of clinical trials, including recruitment. Through a cross-sectional survey and a thematic analysis of free-text responses, we assessed the perceptions of sixteen principal investigators regarding success factors for participant recruitment. Study site involvement and funding source do not necessarily make recruitment easier or more challenging from the perspective of the principal investigators. The most commonly used recruitment strategies are also the most effort inefficient (e.g., in-person recruitment, reviewing the electronic medical records for prescreening). Finally, we recommended actionable steps, such as improving staff support and leveraging informatics-driven approaches, to allow clinical researchers to enhance participant recruitment.

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).

Race and Ethnicity Reporting and Representation in Obstetrics and Gynecology Clinical Trials and Publications From 2007-2020

Importance

Clinical trials guide evidence-based obstetrics and gynecology (OB-GYN) but often enroll nonrepresentative participants.

Objective

To characterize race and ethnicity reporting and representation in US OB-GYN clinical trials and their subsequent publications and to analyze the association of subspecialty and funding with diverse representation.

Design and Setting

Cross-sectional analysis of all OB-GYN studies registered on ClinicalTrials.gov (2007-2020) and publications from PubMed and Google Scholar (2007-2021). Analyses included logistic regression controlling for year, subspecialty, phase, funding, and site number. Data from 332 417 studies were downloaded. Studies with a noninterventional design, with a registration date before October 1, 2007, without relevance to OB-GYN, with no reported results, and with no US-based study site were excluded.

Exposures

OB-GYN subspecialty and funder.

Main Outcomes and Measures

Reporting of race and ethnicity data and racial and ethnic representation (the proportion of enrollees of American Indian or Alaskan Native, Asian, Black, Latinx, or White identity and odds of representation above US Census estimates by race and ethnicity).

Results

Among trials with ClinicalTrials.gov results (1287 trials with 591 196 participants) and publications (1147 trials with 821 111 participants), 662 (50.9%) and 856 (74.6%) reported race and ethnicity data, respectively. Among publications, gynecology studies were significantly less likely to report race and ethnicity than obstetrics (adjusted odds ratio [aOR], 0.54; 95% CI, 0.38-0.75). Reproductive endocrinology and infertility trials had the lowest odds of reporting race and ethnicity (aOR, 0.14; 95% CI, 0.07-0.27; reference category, obstetrics). Obstetrics and family planning demonstrated the most diverse clinical trial cohorts. Compared with obstetric trials, gynecologic oncology had the lowest odds of Black representation (ClinicalTrials.gov: aOR, 0.04; 95% CI, 0.02-0.09; publications: aOR, 0.06; 95% CI, 0.03-0.11) and Latinx representation (ClinicalTrials.gov: aOR, 0.05; 95% CI, 0.02-0.14; publications: aOR, 0.23; 95% CI, 0.10-0.48), followed by urogynecology and reproductive endocrinology and infertility. Urogynecology (ClinicalTrials.gov: aOR, 0.15; 95% CI, 0.05-0.39; publications: aOR, 0.24; 95% CI, 0.09-0.58) had the lowest odds of Asian representation.

Conclusions and Relevance

Race and ethnicity reporting and representation in OB-GYN trials are suboptimal. Obstetrics and family planning trials demonstrate improved representation is achievable. Nonetheless, all subspecialties should strive for more equitably representative research.

Indicators of questionable research practices were identified in 163,129 randomized controlled trials

OBJECTIVES

To explore indicators of the following questionable research practices (QRPs) in randomized controlled trials (RCTs): (1) risk of bias in four domains (random sequence generation, allocation concealment, blinding of participants and personnel, and blinding of outcome assessment); (2) modifications in primary outcomes that were registered in trial registration records (proxy for selective reporting bias); (3) ratio of the achieved to planned sample sizes; and (4) statistical discrepancy.

STUDY DESIGN AND SETTING

Full texts of all human RCTs published in PubMed in 1996-2017 were automatically identified and information was collected automatically. Potential indicators of QRPs included author-specific, publication-specific, and journal-specific characteristics. Beta, logistic, and linear regression models were used to identify associations between these potential indicators and QRPs.

RESULTS

We included 163,129 RCT publications. The median probability of bias assessed using Robot Reviewer software ranged between 43% and 63% for the four risk of bias domains. A more recent publication year, trial registration, mentioning of CONsolidated Standards Of Reporting Trials-checklist, and a higher journal impact factor were consistently associated with a lower risk of QRPs.

CONCLUSION

This comprehensive analysis provides an insight into indicators of QRPs. Researchers should be aware that certain characteristics of the author team and publication are associated with a higher risk of QRPs.

Estimating the effect of COVID-19 on trial design characteristics: a registered report

There have been reports of poor-quality research during the COVID-19 pandemic. This registered report assessed design characteristics of registered clinical trials for COVID-19 compared to non-COVID-19 trials to empirically explore the design of clinical research during a pandemic and how it compares to research conducted in non-pandemic times. We did a retrospective cohort study with a 1 : 1 ratio of interventional COVID-19 registrations to non-COVID-19 registrations, with four trial design outcomes: use of control arm, randomization, blinding and prospective registration. Logistic regression was used to estimate the odds ratio of investigating COVID-19 versus not COVID-19 and estimate direct and total effects of investigating COVID-19 for each outcome. The primary analysis showed a positive direct and total effect of COVID-19 on the use of control arms and randomization. It showed a negative direct effect of COVID-19 on blinding but no evidence of a total effect. There was no evidence of an effect on prospective registration. Taken together with secondary and sensitivity analyses, our findings are inconclusive but point towards a higher prevalence of key design characteristics in COVID-19 trials versus controls. The findings do not support much existing COVID-19 research quality literature, which generally suggests that COVID-19 led to a reduction in quality. Limitations included some data quality issues, minor deviations from the pre-registered plan and the fact that trial registrations were analysed which may not accurately reflect study design and conduct. Following in-principle acceptance, the approved stage 1 version of this manuscript was pre-registered on the Open Science Framework at https://doi.org/10.17605/OSF.IO/5YAEB. This pre-registration was performed prior to data analysis.

Characteristics of Depression Clinical Trials Registered on ClinicalTrials.gov

Background

Mental disorders are among the leading causes of the global health-related burden, and depression is one of the most disabling mental disorders. The emergence of the COVID-19 pandemic has created an environment where many determinants of mental health are exacerbated. Many studies have been registered and conducted over the past 16 years, but how to choose the proper design for depression clinical trials remains the main concern. This study aimed to characterize the current status of global depression clinical trials registered on ClinicalTrials.gov.

Methods

We examined all the trials registered on ClinicalTrials.gov from 2007 to 2021.

Results

Overall, 7623 depression clinical trials were identified for analysis. Of those trials, 6402 (83.98%) were intervention trials and 1212 (15.90%) were observational trials. The majority of intervention types were behavioral (35.2%) and drug (28.55%), with very few procedures, dietary supplements, and diagnostic test studies. In addition, 55.53% of trials enrolled <100 participants. The proportions of trials registered in North America were higher than on other continents. Furthermore, the trials that involved only females (12.6%) were more than only males (0.87%) from 2019 to 2021.

Conclusion

Depression clinical trials registered on ClinicalTrials.gov were dominated by small sample size trials, and there is a lack of trials related to COVID-19. The choice of study design is crucial, and properly designed trials can help improve study efficiency and reduce the likelihood of study failure. Given the increased number of RCT trials, the trial quality is gradually improving over the years. In addition, depression trials concentrating on children and older adults need more scientific attention. Further studies related to COVID-19 are needed, given the great damage that causes to people's physical and mental health.

How many US obstetrical trials reach publication? A cross-sectional analysis of ClinicalTrials.gov and PubMed from 2007 to 2019

BACKGROUND

Obstetrical clinical trials are the foundation of evidence-based medicine during pregnancy. As more obstetrical trials are conducted, understanding the publication characteristics of these trials is of utmost importance to advance obstetrical health.

OBJECTIVE

This study aimed to characterize the frequency of publication and trial characteristics associated with publication among obstetrical clinical trials in the United States. We additionally sought to examine time from trial completion to publication.

STUDY DESIGN

This was a cross-sectional analysis of completed obstetrical trials with an intervention design and at least 1 site in the United States registered to ClinicalTrials.gov from 2007 to 2019. Trial characteristics were cross-referenced with PubMed to determine publication status up to 2021 using the National Clinical Trial identification number. Bivariable analyses were conducted to determine trial characteristics associated with publication. Multivariable logistic regression models controlling for prespecified covariates were generated to estimate the relationship between funding, primary purpose, and therapeutic foci with publication. Additional exploratory analyses of other trial characteristics were conducted. Time to publication was analyzed using Kaplan-Meier curves and Cox regression models.

RESULTS

Of the 1879 obstetrical trials with registered completion, a total of 575 (30.6%) had at least 1 site in the United States, were completed before October 1, 2019, and were included in this analysis. Between October 2007 and October 2019, fewer than two-thirds (N=348, 60.5%) of trials reached publication. Annual rates of publication ranged from 46.4% in 2018 to 70.0% in 2007. No difference was observed in publication by funding, primary purpose, or therapeutic foci (all P>.05). Trials with characteristics indicating high trial quality-including randomized allocation scheme, ≥50 participants enrolled, ≥2 sites, and presence of a data safety monitoring committee-had increased odds of publication compared with those without such characteristics (all P<.05). For example, studies with randomized allocation of intervention had 2-fold greater odds of publication than nonrandomized studies (adjusted odds ratio, 2.09; 95% confidence interval, 1.30-3.37). Studies with ≥150 participants had nearly 8-fold odds of publication (adjusted odds ratio, 7.90; 95% confidence interval, 3.78-17.49) relative to studies with <50 participants. Temporal analysis demonstrated variability in time to publication among obstetrical trials, with a median time of 20.1 months after trial completion, and with most trials that reached publication having been published by 40 months. No difference was observed in time to publication by funding, primary purpose, or therapeutic foci (all P>.05).

CONCLUSION

Publication of obstetrical trials remains suboptimal, with significant differences observed between trials with indicators of high quality and those without. Most trials that reach publication are published within 2 years of registered completion on ClinicalTrials.gov.

Characteristics of clinical trials for non-small cell lung cancer therapeutic vaccines registered on ClinicalTrials.gov

Background

Even after complete surgical treatment or chemotherapy, Non-Small Cell Lung Cancer (NSCLC) patients are also at substantial risk for recurrence and spread trend. Therapeutic cancer vaccination could increase the anti-tumor immune response and prevent tumor relapse. This study aimed to assess the characteristics of NSCLC therapeutic vaccines registered on ClinicalTrials.gov.

Methods

We conducted a cross-sectional, descriptive study of clinical trials for Non-Small Cell Lung Cancer Therapeutic Vaccines Registered on ClinicalTrials.gov (https://clinicaltrials.gov/) through March 17, 2022.

Results

This study encompassed 117 registered trials included for data analysis. The number of trials was significantly correlated with a beginning year (r = 0.504, P < 0.010). Of these trials, 45.30% were completed, 12.82% were terminated, and 8.55% were withdrawn. More than half of trials (52.99%) were funded by industry, and more than half of trials (52.14%) were located in economically developed North America. Regarding study designs of these trials, 27.35% were randomized, 52.14% were single group assignment, 83.76% were without masking, 35.90% were phase 1, and more than half of the trials (56.41%) recruited less than 50 participants. The highest proportion of vaccine types was protein/peptide vaccines (41.88%). Regarding TNM staging, the highest proportion of the trials is stage III-IV (26.50%).

Conclusion

The number of clinical trials about the cancer therapeutic vaccines was sustained an increase in recent years. The main characteristic of clinical trials for NSCLC therapeutic vaccines is lack of randomized control, lack of mask, and recruiting less than 50 participants. In recent years, the protein/peptide vaccines for NSCLC active immunotherapy have been well studied.

Panoramic quality assessment tool for investigator initiated trials

Objectives

Quality can be a challenge for Investigator initiated trials (IITs) since these trials are scarcely overseen by a sponsor or monitoring team. Therefore, quality assessment for departments managing clinical research grants program is important and urgently needed. Our study aims at developing a handy quality assessment tool for IITs that can be applied by both departments and project teams.

Methods

The framework of the quality assessment tool was developed based on the literature studies, accepted guidelines and the Delphi method. A total of 272 ongoing IITs funded by Shanghai non-profit organizations in 2015 and 2016 were used to extract quality indexes. Confirmatory factor analysis (CFA) was used to further evaluate the validity and feasibility of the conceptual quality assessment tool.

Results

The tool consisted of 4 critical quality attributes, including progress, quality, regulation, scientificity, and 13 observed quality indexes. A total of 257 IITs were included in the validity and feasibility assessment. The majority (60.29%) were Randomized Controlled Trial (RCT), and 41.18% were multi-center studies. In order to test the validity and feasibility of IITs quality assessment tool, CFA showed that the model fit the data adequately. (CMIN/DF = 1.868, GFI = 0.916; CFI = 0.936; TLI = 0.919; RMSEA = 0.063; SRMR = 0.076). Different types of clinical studies fit well in the tool. However, RCT scored lower than prospective cohort and retrospective study in enrollment progress (7.02 vs. 7.43, 9.63, respectively).

Conclusion

This study established a panoramic quality assessment tool based on the Delphi method and CFA, and the feasibility and effectiveness of the tool were verified through clinical research examples. The use of this tool can help project management departments effectively and dynamically manage research projects, rationally allocate resources, and ensure the quality of IITs.

Statistical Analysis Plan for the INTEnsive Care Bundle with Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial: A Stepped-Wedge Cluster Randomized Controlled Trial

The third INTEnsive care bundle with blood pressure Reduction in Acute Cerebral hemorrhage Trial (INTERACT3) is an international, multicenter, stepped-wedge (4 phases/3 steps) cluster randomized trial involving 110 hospitals in mainly low- and middle-income countries during 2017-2022. The aim is to determine the effectiveness of a goal-directed care bundle of intensive blood pressure (BP) lowering, glycemic control, antipyrexia, and anticoagulation reversal treatment versus usual standard of care, in patients with acute intracerebral hemorrhage (ICH). After a "usual care" period, hospitals were randomly allocated to implementing care-bundle protocols for control targets (systolic BP <140 mm Hg; glucose 6.1-7.8/7.8-10.0 mmol/L according to diabetes mellitus status; temperature ≤37.5°C; normalization of anticoagulation). A sample size of 8,360 patients (mean 19 per phase per site) provides 90% power (α = 0.05) for a 5.6% absolute improvement in the primary outcome of scores on the modified Rankin scale at 6 months, analyzed by ordinal logistic regression. A detailed statistical analysis plan (SAP) was developed to prespecify the method of analysis for all outcomes and key variables collected in the trial. The primary analysis will use ordinal logistic regression adjusted for the stepped-wedge design. The SAP also includes planned sensitivity analyses, including covariate adjustments, missing data imputations, and subgroup analysis. This SAP allows transparent, verifiable, and prespecified analyses in consideration of the challenges in conducting the study during the COVID pandemic. It also avoids analysis bias arising from prior knowledge of the findings in determining the benefits and harms of a care bundle in acute ICH.

A comparison of registered and published primary outcomes in clinical trials of opioid use disorder: ACTTION review and recommendations

BACKGROUND AND AIMS

Prospective trial registration can increase research integrity. This Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) review was designed to compare the primary outcomes (PO) reported in registries with associated publications for opioid use disorder (OUD) clinical trials.

DESIGN

The World Health Organization's International Clinical Trials Registry Platform (ICTRP) was searched for completed trials (2010 through 2019). Associated publications were identified and paired with trial registry data based on the publication date.

MEASUREMENTS

Reviewers independently rated the occurrence of discrepancies between the POs in the registry compared to the publication. An analysis of prospective versus retrospective registration was also completed.

FINDINGS

One-hundred and forty trials were identified in the search, and 43 registry-publication pairs evaluated. Only 34 of the 43 pairs could be examined for discrepancies because nine did not report a PO in registry and publication. Of the 34 pairs, only four met rigorous criteria for prospective trial registration and had an exact match of POs. In contrast, the majority of the 34 trials, or 80%, had inconsistent POs (e.g., registered secondary outcomes published as primary; the timing of PO not specified) and/or were retrospectively registered.

CONCLUSIONS

Many clinical trials focused on OUD have not met the standards of trial registration, such as consistent reporting of POs and prospective registration. Failure to properly register trial characteristics undermines the validity of research findings and can delay the development of life-saving treatments. Recommendations for improving prospective trial reporting practices are provided.

Registered Clinical Trials Comprising Pregnant Women in China: A Cross-Sectional Study

Background: In this study, an investigation was conducted on clinical drug trials comprising pregnant women in China that provided data on the quantity, properties, source of funding, and geographical distribution regarding registration and post-marketing studies.

Methods: We conducted a cross-sectional descriptive study of clinical trials of pregnant women in China on 30 December 2021, and it was registered on the official Drug Clinical Trial Information Management Platform (ChiCTR) (http://www.chinadrugtrials.org.cn) established by the State Food and Drug Administration of China (Chinese FDA).

Results: This study encompassed 72 registered trials (0.46%, 72/15,539) for data analysis. Of these trials, 43.1% of trials were started between 2013 and 2016, and nearly half of the trials (48.6%) were completed. Industries were listed as the primary sponsor for 95.8% trials. Economically developed eastern China and northern China, accounting for 69.5% of the 72 registered trials, were the most frequently identified study locations. Regarding study designs of these trials, more than half of the trials (70.8%) were randomized, 61.1% were a parallel assignment, 33.3% were phase 3, and half of the trials (54.2%) were open label. In total, 23 trials met the requirements after excluding trials of cancer and/or of postmenopausal women, accounting for 0.15% of the 15,539 registered trials in the ChiCTR websites. Of the 72 clinical trials, 54 drugs for 18 indications were included. Of these indications, the highest proportion of the trials is osteoporosis (27.8%), followed by cancer (22.2%), assisted reproduction (13.9%), and other indications (13.9%).

Conclusion: This survey revealed a significant shortage of the development, evaluation, and safety trials of pregnancy-related drugs in China. Modifying or adding legislation and providing financial incentives may therefore encourage pharmaceutical companies to conduct additional clinical trials on pregnant women.

Clinical Trials of Liposomes in Children’s Anticancer Therapy: A Comprehensive Analysis of Trials Registered on ClinicalTrials.gov

Objective

Clinical trials have become essential for driving the development of medicine. However, little is known about the current status of clinical trials on liposomes in children’s anticancer therapy (LCAT). This study aimed to synthesize current finding from clinical trials of LCAT in ClinicalTrials.gov.

Methods

A cross-sectional descriptive study of clinical trials on LCAT was conducted, using studies registered on ClinicalTrials.gov through December 30, 2021.

Results

A total of 74 eligible trials were identified, accounting for 4.8% (74/1552) of all trials on liposomes for cancer therapy. Among these trials, 70 (94.6%) were interventional trials, and the remaining 4 (5.4%) were observational trials. Of the 70 interventional trials, 63 (90.0%) were for treatment, 48.6% were involving unlabeled allocations, 30.0% were randomized, 52.9% were single group assignment, 71.4% were without masking, 28.6% were Phase 3 trials, 30.0% were Phase 1 trials, and 24.3% were Phase 2 trials. Furthermore, 17 liposomal drugs for 123 types of cancer were investigated in the interventional trials, and these were mainly focused on organic chemicals (43/70, 61.4%). Of these cancers, the highest proportion was leukemia (15.4%), followed by lymphoma (9.8%) and ovarian cancer (8.9%).

Conclusion

High quality, adequately powered, masked, appropriately sized, and randomized clinical trials represent the critical priorities for conducting a high-quality clinical trial. However, most of these trials for LCAT were non-randomized, single group assignment, and non-blinded interventional trials of small scale, with various eligibility criteria and outcome measures. Our analysis highlights the need for improvement in the completeness of study designs curated on clinicalTrials.gov. We urge for decision-makers to avoid adopting entrenched positions about the study design of cancer clinical trials to avoid this problem. As such, tackling the problematic challenges related to cancer and designing efficient trials for cancer requires developing and applying new approaches and multiple strategies.

Early Discontinuation, Results Reporting, and Publication of Pediatric Clinical Trials

BACKGROUND AND OBJECTIVES

Unique ethical, epidemiological, and economic factors are barriers to performing research in children. The landscape of pediatric clinical trials, including drivers of completion and timely dissemination of results, is not well understood. We aimed to characterize the prevalence of and factors associated with early discontinuation, results reporting, and publication of pediatric clinical trials registered at ClinicalTrials.gov.

METHODS

Cross-sectional analysis of clinical trials enrolling participants <18 years old registered at ClinicalTrials.gov from October 2007 to March 2020. Multivariable logistic regressions were performed to assess the association between trial characteristics and primary outcomes. Publication data were obtained through PubMed, ClinicalTrials.gov, Embase, and Scopus.

RESULTS

Overall, 11.1% trials were stopped early, with recruitment failure being the predominant reason for discontinuation. Only 23.5% of completed trials reported results, and 38.8% were published within 3 years of completion. Rates of discontinuation and publication significantly improved over the study period. Among funding sources, government-sponsored trials (adjusted odds ratio [aOR], 0.72; 95% CI, 0.47-0.97) and academic trials (aOR, 0.64; 95% CI, 0.50-0.82) had lower odds of discontinuation compared with industry trials and were more likely to be published (government: aOR, 1.94 [95% CI, 1.52-2.48] academic: aOR, 1.61 [95% CI, 1.35-1.92). Academic trial investigators were the least likely to report results (aOR, 0.34; 95% CI, 0.31-0.52).

CONCLUSIONS

Early discontinuation and nonreporting/nonpublication of findings remain common in registered pediatric clinical trials and were associated with funding source and other trial features. Targeted efforts are needed to support trial completion and timely results dissemination toward strengthening evidence-based pediatric medicine.

Uptake of the multi-arm multi-stage (MAMS) adaptive platform approach: a trial-registry review of late-phase randomised clinical trials

BACKGROUND

For medical conditions with numerous interventions worthy of investigation, there are many advantages of a multi-arm multi-stage (MAMS) platform trial approach. However, there is currently limited knowledge on uptake of the MAMS design, especially in the late-phase setting. We sought to examine uptake and characteristics of late-phase MAMS platform trials, to enable better planning for teams considering future use of this approach.

DESIGN

We examined uptake of registered, late-phase MAMS platforms in the EU clinical trials register, Australian New Zealand Clinical Trials Registry, International Standard Randomised Controlled Trial Number registry, Pan African Clinical Trials Registry, WHO International Clinical Trial Registry Platform and databases: PubMed, Medline, Cochrane Library, Global Health Library and EMBASE. Searching was performed and review data frozen on 1 April 2021. MAMS platforms were defined as requiring two or more comparison arms, with two or more trial stages, with an interim analysis allowing for stopping of recruitment to arms and typically the ability to add new intervention arms.

RESULTS

62 late-phase clinical trials using an MAMS approach were included. Overall, the number of late-phase trials using the MAMS design has been increasing since 2001 and been accelerated by COVID-19. The majority of current MAMS platforms were either targeting infectious diseases (52%) or cancers (29%) and all identified trials were for treatment interventions. 89% (55/62) of MAMS platforms were evaluating medications, with 45% (28/62) of the MAMS platforms having at least one or more repurposed medication as a comparison arm.

CONCLUSIONS

Historically, late-phase trials have adhered to long-established standard (two-arm) designs. However, the number of late-phase MAMS platform trials is increasing, across a range of different disease areas. This study highlights the potential scope of MAMS platform trials and may assist research teams considering use of this approach in the late-phase randomised clinical trial setting.

PROSPERO REGISTRATION NUMBER

CRD42019153910.

A web-based tool for automatically linking clinical trials to their publications

OBJECTIVE

Evidence synthesis teams, physicians, policy makers, and patients and their families all have an interest in following the outcomes of clinical trials and would benefit from being able to evaluate both the results posted in trial registries and in the publications that arise from them. Manual searching for publications arising from a given trial is a laborious and uncertain process. We sought to create a statistical model to automatically identify PubMed articles likely to report clinical outcome results from each registered trial in ClinicalTrials.gov.

MATERIALS AND METHODS

A machine learning-based model was trained on pairs (publications known to be linked to specific registered trials). Multiple features were constructed based on the degree of matching between the PubMed article metadata and specific fields of the trial registry, as well as matching with the set of publications already known to be linked to that trial.

RESULTS

Evaluation of the model using known linked articles as gold standard showed that they tend to be top ranked (median best rank = 1.0), and 91% of them are ranked in the top 10.

DISCUSSION

Based on this model, we have created a free, public web-based tool that, given any registered trial in ClinicalTrials.gov, presents a ranked list of the PubMed articles in order of estimated probability that they report clinical outcome data from that trial. The tool should greatly facilitate studies of trial outcome results and their relation to the original trial designs.

Practical Tools and Guidelines for Young Oncologists From Resource-Limited Settings to Publish Excellence and Advance Their Career

Cancer research is evolving worldwide. However, publishing high-quality academic literature in oncology remains challenging for authors in the developing world. Young oncologists in low- and middle-income countries experience several barriers including lack of funding and research facilities, as well as inadequate training. Publication best practices, science integrity, and ethics are required to improve oncology research quality and therefore, improve patients' care in these countries. To achieve this goal, we propose some basic principles and tools that may help young oncologists especially in developing countries overcome these issues and boost their academic careers.

Validation of lipid-related therapeutic targets for coronary heart disease prevention using human genetics

Drug target Mendelian randomization (MR) studies use DNA sequence variants in or near a gene encoding a drug target, that alter the target's expression or function, as a tool to anticipate the effect of drug action on the same target. Here we apply MR to prioritize drug targets for their causal relevance for coronary heart disease (CHD). The targets are further prioritized using independent replication, co-localization, protein expression profiles and data from the British National Formulary and clinicaltrials.gov. Out of the 341 drug targets identified through their association with blood lipids (HDL-C, LDL-C and triglycerides), we robustly prioritize 30 targets that might elicit beneficial effects in the prevention or treatment of CHD, including NPC1L1 and PCSK9, the targets of drugs used in CHD prevention. We discuss how this approach can be generalized to other targets, disease biomarkers and endpoints to help prioritize and validate targets during the drug development process.

Clinical trials and tribulations: lessons from spinal cord injury studies registered on ClinicalTrials.gov

STUDY DESIGN

Article.

OBJECTIVE

ClinicalTrials.gov is an online trial registry that provides public access to information on past, present, and future clinical trials. While increasing transparency in research, the quality of the information provided in trial registrations is highly variable. The objective of this study is to assess key areas of information on ClinicalTrials.gov in interventional trials involving people with spinal cord injuries.

SETTING

Interventional trials on ClinicalTrials.gov involving people with spinal cord injuries.

METHODS

A subset of data on interventional spinal cord injury trials was downloaded from ClinicalTrials.gov. Reviewers extracted information pertaining to study type, injury etiology, spinal cord injury characteristics, timing, study status, and results.

RESULTS

Of the interventional trial registrations reviewed, 62.5%, 58.6%, and 24.3% reported injury level, severity, and etiology, respectively. The timing of intervention relative to injury was reported in 72.8% of registrations. Most trials identified a valid study status (89.2%), but only 23.5% of those completed studies had posted results.

CONCLUSIONS

Our review provides a snapshot of interventional clinical trials conducted in the field of spinal cord injury and registered in ClinicalTrials.gov. Areas for improvement were identified with regards to reporting injury characteristics, as well as posting results.

Lipid-based nanoparticles for psoriasis treatment: a review on conventional treatments, recent works, and future prospects

Psoriasis is a lingering inflammatory skin disease that attacks the immune system. The abnormal interactions between T cells, immune cells, and inflammatory cytokines causing the epidermal thickening. International guidelines have recommended topical treatments for mild to moderate psoriasis whilst systemic and phototherapy treatments for moderate to severe psoriasis. However, current therapeutic approaches have a wider extent to treat moderate to severe type of psoriasis especially since the emergence of diverse biologic agents. In the meantime, topical delivery of conventional treatments has prompted many unsatisfactory effects to penetrate through the skin (stratum corneum). By understanding the physiology of stratum corneum barrier functions, scientists have developed different types of lipid-based nanoparticles like solid lipid nanoparticles, nanostructured lipid carriers, nanovesicles, and nanoemulsions. These novel drug delivery systems help the poorly solubilised active pharmaceutical ingredient reaches the targeted site seamlessly because of the bioavailability feature of the nanosized molecules. Lipid-based nanoparticles for psoriasis treatments create a paradigm for topical drug delivery due to their lipids' amphiphilic feature to efficiently encapsulate both lipophilic and hydrophilic drugs. This review highlights different types of lipid-based nanoparticles and their recent works of nano formulated psoriasis treatments. The encapsulation of psoriasis drugs through lipid nanocarriers unfold numerous research opportunities in pharmaceutical applications but also draw challenges for the future development of nano drugs.

A blueprint for translational regenerative medicine

The past few decades have produced a large number of proof-of-concept studies in regenerative medicine. However, the route to clinical adoption is fraught with technical and translational obstacles that frequently consign promising academic solutions to the so-called "valley of death." Here, we present a proposed blueprint for translational regenerative medicine. We offer principles to help guide the selection of cells and materials, present key in vivo imaging modalities, and argue that the host immune response should be considered throughout design and development. Last, we suggest a pathway to navigate the often complex regulatory and manufacturing landscape of translational regenerative medicine.

Current landscape of type 1 diabetes mellitus-related interventional clinical trials registered on ClinicalTrials.gov: a cross-sectional study

AIMS

A better understanding of the current features of type 1 diabetes mellitus (T1DM)-related interventional clinical trials is important for improving clinical trial designs and identifying neglected research areas. Therefore, this study aimed to comprehensively assess T1DM-related interventional clinical trials registered in the ClinicalTrials.gov database.

METHODS

In this cross-sectional study, T1DM-related clinical trials registered in the ClinicalTrials.gov database were searched on July 1, 2020. The characteristics of the relevant trials were assessed. PubMed and Google Scholar were used to search for publication statuses of primary completed studies.

RESULTS

Overall, 1,421 T1DM-related interventional clinical trials were identified for analysis. Of those trials, 509 (35.8%) involved children and 912 (64.2%) involved only adults. Overall, 63.2% of trials enrolled < 50 participants and 61.9% were registered after patient recruitment. Most trials were single-centered (66.0%). The proportions of trials with children were higher than those with only adults with respect to the primary purpose of health service or prevention (13.6% vs. 4.8%), intervention of device (30.8% vs. 23.9%), education or lifestyle (28.9% vs. 11.3%), and dietary supplement (5.7% vs. 2.5%) (all P < 0.01). Only 24.0% of trials had available results after primary completion. The 5-year cumulative publication rate after primary trial completion was < 40%.

CONCLUSIONS

T1DM-related interventional clinical trials registered in ClinicalTrials.gov were dominated by small single-center studies. Most trials lacked the availability of results and their respective publications. Large multicenter interventional clinical trials on T1DM are needed, and more attention should be paid to improve the publication and dissemination of clinical trials results.

Public availability of results of ClinicalTrials.gov-registered expanded access studies

AIMS

Expanded access is the use of investigational treatments outside of clinical trials. Results of expanded access studies provide insights into how investigational treatments work in real-world settings. The objective of this study was to evaluate public availability of results of expanded access studies.

METHODS

Eligible expanded access studies were identified in ClinicalTrials.gov (CT.gov). Publications matching records of individual studies were searched for in Medline and Embase. In addition, we assessed whether results of the included studies were publicly available from other sources including CT.gov, sponsor web sites and conference proceedings.

RESULTS

After median time of 49.5 (interquartile range, 36.7-64.7) months from study completion, the results of 69 out of the 152 included studies (45.39%) were publicly available, either as a journal publication (53 studies; 34.87%) or from other source (16 studies; 10.52%). The percentage of studies whose results were available as a journal publication after 12, 24, 36 and 48 months from study completion was 13.2, 21.1, 33.1 and 35.7%, respectively. The percentage of studies whose results were publicly available from any source (including journal publications) at 12, 24, 36 and 48 months were 19.1, 29.6, 43.2 and 47.5%, respectively.

CONCLUSION

Results of a considerable proportion of expanded access studies are not publicly available. In view of the growing importance of real-world data, sponsors and principal investigators of those studies should always consider making their findings public.

Evaluation of Oncology Trial Results Reporting Over a 10-Year Period

IMPORTANCE

Unreported clinical trial results represent a violation of human rights. Oncology trials account for nearly 30% of interventional biopharmaceutical clinical studies registered on ClinicalTrials.gov and are the most numerous among all disciplines.

OBJECTIVE

To analyze the reporting of results among all interventional oncology trials registered on ClinicalTrials.gov from 2007 through 2017.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed all clinical studies registered between June 1, 2007, and May 8, 2017, on ClinicalTrials.gov, the largest public clinical trial registry in the world. Trials with a recruitment status of completed or terminated and a primary completion date of on or before September 30, 2017, were selected. Data were analyzed between February 20, 2021, and February 26, 2021.

MAIN OUTCOMES AND MEASURES

The main outcome was the percentage of trials that reported results either on ClinicalTrials.gov or in journal publications within 24 months of the primary completion date. Journal publication was ascertained by searching ClinicalTrials.gov for a link to the publication, PubMed using national clinical trial number, and Embase using national clinical trial number and filters.

RESULTS

Of the 12 240 clinical trials registered in ClinicalTrials.gov, 7425 trials (60.7%; 95% CI, 60.0%-61.5%) reported results, with a 34.0% (95% CI, 30.3%-37.7%) increase in 24-month reporting rate from 2007 to 2017. Multivariable analyses confirmed that more recent trials (adjusted hazard ratio [HR], 1.11 per year increase; 95% CI, 1.10-1.13) and trials with larger sample sizes (51-100 patients: adjusted HR, 1.17 [95% CI, 1.09-1.24]; >100 patients: adjusted HR, 1.43 [95% CI, 1.33-1.54]) were more likely to report results. Terminated trials were less likely to report results compared with completed trials (adjusted HR, 0.88; 95% CI, 0.83-0.93). Compared with trials funded by industry, those funded by the National Institutes of Health were more likely to report results (adjusted HR, 1.39; 95% CI, 1.29-1.49), whereas those funded by other academic or nonprofit organizations were less likely to report results (adjusted HR, 0.66; 95% CI, 0.62-0.70). Among all 7425 trials, the results of 2807 trials (37.8%; 95% CI, 36.7%-38.9%) were posted only on ClinicalTrials.gov. These trials tended to be terminated early and to have small sample sizes (≤50 patients) compared with trials that published results in journals.

CONCLUSIONS AND RELEVANCE

This study found a gradual improvement in results reporting among oncology trials over a 10-year period. Trial registries could serve as a results reporting platform for unpublished trials and as a data source of trial outcomes for future studies.

The methodological quality of 176,620 randomized controlled trials published between 1966 and 2018 reveals a positive trend but also an urgent need for improvement

Many randomized controlled trials (RCTs) are biased and difficult to reproduce due to methodological flaws and poor reporting. There is increasing attention for responsible research practices and implementation of reporting guidelines, but whether these efforts have improved the methodological quality of RCTs (e.g., lower risk of bias) is unknown. We, therefore, mapped risk-of-bias trends over time in RCT publications in relation to journal and author characteristics. Meta-information of 176,620 RCTs published between 1966 and 2018 was extracted. The risk-of-bias probability (random sequence generation, allocation concealment, blinding of patients/personnel, and blinding of outcome assessment) was assessed using a risk-of-bias machine learning tool. This tool was simultaneously validated using 63,327 human risk-of-bias assessments obtained from 17,394 RCTs evaluated in the Cochrane Database of Systematic Reviews (CDSR). Moreover, RCT registration and CONSORT Statement reporting were assessed using automated searches. Publication characteristics included the number of authors, journal impact factor (JIF), and medical discipline. The annual number of published RCTs substantially increased over 4 decades, accompanied by increases in authors (5.2 to 7.8) and institutions (2.9 to 4.8). The risk of bias remained present in most RCTs but decreased over time for allocation concealment (63% to 51%), random sequence generation (57% to 36%), and blinding of outcome assessment (58% to 52%). Trial registration (37% to 47%) and the use of the CONSORT Statement (1% to 20%) also rapidly increased. In journals with a higher impact factor (>10), the risk of bias was consistently lower with higher levels of RCT registration and the use of the CONSORT Statement. Automated risk-of-bias predictions had accuracies above 70% for allocation concealment (70.7%), random sequence generation (72.1%), and blinding of patients/personnel (79.8%), but not for blinding of outcome assessment (62.7%). In conclusion, the likelihood of bias in RCTs has generally decreased over the last decades. This optimistic trend may be driven by increased knowledge augmented by mandatory trial registration and more stringent reporting guidelines and journal requirements. Nevertheless, relatively high probabilities of bias remain, particularly in journals with lower impact factors. This emphasizes that further improvement of RCT registration, conduct, and reporting is still urgently needed.

Many randomized controlled trials (RCTs) are biased and difficult to reproduce due to methodological flaws and poor reporting. Analysis of 176,620 RCTs published between 1966 and 2018 reveals that the risk of bias in RCTs generally decreased. Nevertheless, relatively high probabilities of bias remain, showing that further improvement of RCT registration, conduct, and reporting is still urgently needed.

Evolving landscape and academic attitudes toward the controversies of global immuno-oncology trials

This cross‐sectional and longitudinal descriptive analysis aimed to track the evolving landscape of global immuno‐oncology (IO) trials and provide insight into the resolution of IO‐related controversies. Clinical trials (n = 4510) registered on ClinicalTrials.gov in 2007 to 2019 studying immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT), cancer vaccines and immune modulators were included. Most of IO trials are Phase 2 and focus on ICIs and multiple IO therapies. The United States leads global IO research, with stable growth and the best methodological quality. Mainland China ranks first in the number of ACT trials but has the lowest article publication rate (6.2%). A multiple‐arm comparative design is often adopted in multiple IO therapies trials (44.0%). Trials studying ICIs and multiple IO therapies are likely to use early registration (80.0% and 86.6%) and stringent corticosteroid‐/infection‐related criteria. Hospitals have provided the most extensive and strongest support for all IO categories. Big pharma prefers to fund Phase 3‐4 ICI trials (6.98%), while small pharma has a wider sponsorship favoring Phase 1‐2 trials. The “partial‐use‐of‐corticosteroids” strategy is generally well accepted in ICI trials with a definitive trend (32.5%; P < .001) but is associated with the poor dissemination of results (P ≤ .020), while the complete disclosure and standardization of dose/timing limits are still lacking. Disparities in design features and dissemination of results are widespread in IO trials and are modulated by IO category, cancer type and sponsor. We propose policy reforms to redefine the timely publication of IO trials and standardize the resolution of corticosteroid‐/infection‐related issues.

What's new?

In recent decades, immunotherapy has emerged and advanced to become a key part of cancer‐fighting strategies. The rapid growth of immuno‐oncology, however, has been accompanied by controversy in suitable interventions and trial design. In this cross‐sectional and longitudinal analysis, disparities in design were found to be common in immuno‐oncology trials, with differences influenced by factors such as cancer type and trial sponsor. Trials with strict limitations on corticosteroid use had significantly higher publications rates than trials permitting partial corticosteroid administration. The data further suggest that timely publication of immuno‐oncology trials is the third year after trial completion.

Clinical trials in a COVID-19 pandemic: Shared infrastructure for continuous learning in a rapidly changing landscape

Background:

Clinical trials, conducted efficiently and with the utmost integrity, are a key component in identifying effective vaccines, therapies, and other interventions urgently needed to solve the COVID-19 crisis. Yet launching and implementing trials with the rigor necessary to produce convincing results is a complicated and time-consuming process. Balancing rigor and efficiency involves relying on designs that employ flexible features to respond to a fast-changing landscape, measuring valid endpoints that result in translational actions and disseminating findings in a timely manner. We describe the challenges involved in creating infrastructure with potential utility for shared learning.

Methods:

We have established a shared infrastructure that borrows strength across multiple trials. The infrastructure includes an endpoint registry to aid in selecting appropriate endpoints, a registry to facilitate establishing a Data & Safety Monitoring Board, common data collection instruments, a COVID-19 dedicated design and analysis team, and a pragmatic platform protocol, among other elements.

Results:

The authors have relied on the shared infrastructure for six clinical trials for which they serve as the Data Coordinating Center and have a design and analysis team comprising 15 members who are dedicated to COVID-19. The authors established a pragmatic platform to simultaneously investigate multiple treatments for the outpatient with adaptive features to add or drop treatment arms.

Conclusion:

The shared infrastructure provides appealing opportunities to evaluate disease in a more robust manner with fewer resources and is especially valued during a pandemic where efficiency in time and resources is crucial. The most important element of the shared infrastructure is the pragmatic platform. While it may be the most challenging of the elements to establish, it may provide the greatest benefit to both patients and researchers.

Overview of Clinical Trials on Type 2 Diabetes Mellitus: A Comprehensive Analysis of the ClinicalTrials.gov Database

PURPOSE

A better understanding of the current features of type 2 diabetes mellitus (T2DM)-related clinical trials is important for improving designs of clinical trials and identifying neglected areas of research. It was hypothesized that the trial registration policy promoted the designs of T2DM-related trials over the years. Therefore, this study aimed to present a comprehensive overview of T2DM-related clinical trials registered in the ClinicalTrials.gov database.

METHODS

T2DM-related clinical trials registered in the ClinicalTrials.gov database were searched and assessed the characteristics of the relevant trials. We searched PubMed and Google Scholar for the publication statuses of the primary completed trials.

RESULTS

Overall, 5117 T2DM-related trials were identified for analysis. Of the interventional trials, 71.5% had a primary treatment purpose while only 8.9% were prevention or health service. There were more interventional trials registered prior to patient recruitment between 2012 and 2019 than between 2004 and 2011 (44.6% vs 19.9%, P<0.001). The period between 2012 and 2019 also had more trials that enrolled <100 participants (59.2% vs 50.9%), were single-center studies (60.7% vs 50.6%), had non-randomized allocations (11.3% vs 6.3%), were open-label (49.2% vs 45.6%), and had smaller sample sizes than the period between 2004 and 2011 (all P<0.001). The five-year cumulative publication rates after primary completion of the trials were <40%.

CONCLUSION

Although the ClinicalTrials.gov database did not include all clinical trials, the trials registered in the ClinicalTrials.gov database still accounted for most of the clinical studies. Encouragingly, more interventional trials were registered prior to patient recruitment over the years. The majority of T2DM-related clinical trials focused on drug-related treatment, and trials regarding prevention in T2DM should be promoted. More attention should be paid to improve the publication and dissemination of clinical trials results.

Obstacles to the reuse of study metadata in ClinicalTrials.gov

Metadata that are structured using principled schemas and that use terms from ontologies are essential to making biomedical data findable and reusable for downstream analyses. The largest source of metadata that describes the experimental protocol, funding, and scientific leadership of clinical studies is ClinicalTrials.gov. We evaluated whether values in 302,091 trial records adhere to expected data types and use terms from biomedical ontologies, whether records contain fields required by government regulations, and whether structured elements could replace free-text elements. Contact information, outcome measures, and study design are frequently missing or underspecified. Important fields for search, such as condition and intervention, are not restricted to ontologies, and almost half of the conditions are not denoted by MeSH terms, as recommended. Eligibility criteria are stored as semi-structured free text. Enforcing the presence of all required elements, requiring values for certain fields to be drawn from ontologies, and creating a structured eligibility criteria element would improve the reusability of data from ClinicalTrials.gov in systematic reviews, metanalyses, and matching of eligible patients to trials.

Risk and mitigation actions for clinical trials during COVID-19 pandemic (RiMiCOPa)

The COVID-19 virus diffusion is, nowadays, global and any clinical trial is potentially affected by the direct and indirect consequences of the COVID-19 during the pandemic. Any step, from protocol design to result's disclosure, needs to be revised to assess the impact of the COVID-19 on the study, evaluate the potential risks, and establish a mitigation plan. We have developed a series of recommendations, belonging to our experience in any aspect of clinical trials. We hope that the Risk and Mitigation actions for clinical trials during COVID-19 Pandemic (RiMiCOPa) will help all clinical trial professionals, patients, auditors, and assessors to ensure effective data management, statistics, and medical writing standards while conducting clinical trials in the pandemic.

Influence and management of conflicts of interest in randomised clinical trials: qualitative interview study

OBJECTIVE

To characterise and analyse the experiences of trial researchers of if and how conflicts of interest had unduly influenced clinical trials they had worked on, what management strategies they had used to minimise any potential influence, and their experiences and views on conflicts of interest more generally.

DESIGN

Qualitative interview study.

PARTICIPANTS

Trial researchers who had participated in at least 10 clinical trials with methodological or statistical expertise. Researchers differed by geographical location, educational background, and experience with different types of funders. Interviewees were identified by searches on Web of Science and snowball sampling. 52 trial researchers were approached by email; 20 agreed to be interviewed.

SETTING

Interviews conducted by telephone, recorded, transcribed verbatim, imported to NVivo 12, and analysed by systematic text condensation. Semistructured interviews focused on financial and non-financial conflicts of interest.

RESULTS

The interviewees had participated in a median of 37.5 trials and were mainly male physicians who had experience with commercial and non-commercial trial funders. Two predefined themes (influence of conflicts of interest and management strategies) and two additional themes (definition and reporting of conflicts of interest) emerged. Examples of perceived influence of conflicts of interest were: choice of inferior comparator, manipulation of the randomisation process, prematurely stopping the trials, fabrication of data, blocking access to data, and spin (eg, overly favourable interpretation of the results). Examples of strategies to manage conflicts of interest were: disclosure procedures, exclusion of the funder from design and analysis, independent committees, contracts ensuring complete access to the data, and no restriction by the funder on analysis and reporting. Interviewees used different definitions or thresholds for what they considered to be conflicts of interest, and they described different criteria for when to report them. Some interviewees considered non-commercial financial conflicts of interest (eg, funding of trials by governmental health agencies with a political agenda) to be equally or more important than commercial financial conflicts of interest (eg, funding by drug and device companies), but more challenging to report and manage.

CONCLUSION

This study described how trial researchers perceive conflicts of interest unduly influencing clinical trials they had worked on, and the management strategies they used to prevent these influences. The results indicated considerable variability in researchers' understanding of what conflicts of interest are and when they should be reported.

PCSK9 monoclonal antibodies for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Despite the availability of effective drug therapies that reduce low-density lipoprotein (LDL)-cholesterol (LDL-C), cardiovascular disease (CVD) remains an important cause of mortality and morbidity. Therefore, additional LDL-C reduction may be warranted, especially for people who are unresponsive to, or unable to take, existing LDL-C-reducing therapies. By inhibiting the proprotein convertase subtilisin/kexin type 9 (PCSK9) enzyme, monoclonal antibodies (PCSK9 inhibitors) reduce LDL-C and CVD risk.

OBJECTIVES

Primary To quantify the effects of PCSK9 inhibitors on CVD, all-cause mortality, myocardial infarction, and stroke, compared to placebo or active treatment(s) for primary and secondary prevention. Secondary To quantify the safety of PCSK9 inhibitors, with specific focus on the incidence of influenza, hypertension, type 2 diabetes, and cancer, compared to placebo or active treatment(s) for primary and secondary prevention.

SEARCH METHODS

We identified studies by systematically searching CENTRAL, MEDLINE, Embase, and Web of Science in December 2019. We also searched ClinicalTrials.gov and the International Clinical Trials Registry Platform in August 2020 and screened the reference lists of included studies. This is an update of the review first published in 2017.

SELECTION CRITERIA

All parallel-group and factorial randomised controlled trials (RCTs) with a follow-up of at least 24 weeks were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed and extracted data. Where data were available, we calculated pooled effect estimates. We used GRADE to assess certainty of evidence and in 'Summary of findings' tables.

MAIN RESULTS

We included 24 studies with data on 60,997 participants. Eighteen trials randomised participants to alirocumab and six to evolocumab. All participants received background lipid-lowering treatment or lifestyle counselling. Six alirocumab studies used  an active treatment comparison group (the remaining used placebo), compared to three evolocumab active comparison trials. Alirocumab compared with placebo decreased the risk of CVD events, with an absolute risk difference (RD) of -2% (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.80 to 0.94; 10 studies, 23,868 participants; high-certainty evidence), decreased the risk of mortality (RD -1%; OR 0.83, 95% CI 0.72 to 0.96; 12 studies, 24,797 participants; high-certainty evidence), and MI (RD -2%; OR 0.86, 95% CI 0.79 to 0.94; 9 studies, 23,352 participants; high-certainty evidence) and for any stroke (RD 0%; OR 0.73, 95% CI 0.58 to 0.91; 8 studies, 22,835 participants; high-certainty evidence). Compared to active treatment the alirocumab effects, for CVD, the RD was 1% (OR 1.37, 95% CI 0.65 to 2.87; 3 studies, 1379 participants; low-certainty evidence); for mortality, RD was -1% (OR 0.51, 95% CI 0.18 to 1.40; 5 studies, 1333 participants; low-certainty evidence); for MI, RD was 1% (OR 1.45, 95% CI 0.64 to 3.28, 5 studies, 1734 participants; low-certainty evidence); and for any stroke, RD was less than 1% (OR 0.85, 95% CI 0.13 to 5.61; 5 studies, 1734 participants; low-certainty evidence). Compared to placebo the evolocumab, for CVD, the RD was -2% (OR 0.84, 95% CI 0.78 to 0.91; 3 studies, 29,432 participants; high-certainty evidence); for mortality, RD was less than 1% (OR 1.04, 95% CI 0.91 to 1.19; 3 studies, 29,432 participants; high-certainty evidence); for MI, RD was -1% (OR 0.72, 95% CI 0.64 to 0.82; 3 studies, 29,432 participants; high-certainty evidence); and for any stroke RD was less than -1% (OR 0.79, 95% CI 0.65 to 0.94; 2 studies, 28,531 participants; high-certainty evidence).  Compared to active treatment, the evolocumab effects, for any CVD event RD was less than -1% (OR 0.66, 95% CI 0.14 to 3.04; 1 study, 218 participants; very low-certainty evidence); for all-cause mortality, the RD was less than 1% (OR 0.43, 95% CI 0.14 to 1.30; 3 studies, 5223 participants; very low-certainty evidence); and for MI, RD was less than 1% (OR 0.66, 95% CI 0.23 to 1.85; 3 studies, 5003 participants; very low-certainty evidence). There were insufficient data on any stroke.  AUTHORS' CONCLUSIONS: The evidence for the clinical endpoint effects of  evolocumab and alirocumab were graded as high. There is a strong evidence base to prescribe PCSK9 monoclonal antibodies to people who might not be eligible for other lipid-lowering drugs, or to people who cannot meet their lipid goals on more traditional therapies, which was the main patient population of the available trials.  The evidence base of PCSK9 inhibitors compared with active treatment is much weaker (low very- to low-certainty evidence) and it is unclear whether evolocumab or alirocumab might be effectively used as replacement therapies. Related, most of the available studies preferentially enrolled people with either established CVD or at a high risk already, and evidence in low- to medium-risk settings is minimal. Finally, there is very limited evidence on any potential safety issues of both evolocumab and alirocumab. While the current evidence synthesis does not reveal any adverse signals, neither does it provide evidence against such signals. This suggests careful consideration of alternative lipid lowering treatments before prescribing PCSK9 inhibitors.

Clinical Trial Outcomes in Urology: Assessing Early Discontinuation, Results Reporting and Publication in ClinicalTrials.Gov Registrations 2007-2019

PURPOSE

Clinical trials require significant resources, but benefits are only realized after trial completion and dissemination of results. We comprehensively assessed early discontinuation, registry results reporting, and publication by trial sponsor and subspecialty in urology trials.

MATERIALS AND METHODS

We assessed trial registrations from 2007 to 2019 on ClinicalTrials.gov and publication data from PubMed®/MEDLINE®. Associations between sponsor or subspecialty with early discontinuation were assessed using Cox proportional hazards and results reporting or publication with logistic regression at 3 years after completion.

RESULTS

Of 8,636 trials 3,541 (41.0%) were completed and 999 (11.6%) were discontinued. Of completed trials 26.9% reported results and 21.6% were published. Sponsors included academic institutions (53.1%), industry (37.1%) and the U.S. government (9.8%). Academic-sponsored (adjusted HR 0.81, 95% CI 0.69-0.96, p=0.012) and government-sponsored trials (adjusted HR 0.62, 95% CI 0.49-0.78, p <0.001) were less likely than industry to discontinue early. Government-sponsored trials were more likely to report (adjusted OR 1.72, 95% CI 1.17-2.54, p=0.006) and publish (adjusted OR 1.89, 95% CI 1.23-2.89, p=0.004). Academic-sponsored trials were less likely to report (adjusted OR 0.65, CI:0.48-0.88, p=0.006) but more likely to publish (adjusted OR 1.72, 95% CI 1.25-2.37, p <0.001). These outcomes were similar across subspecialties. However, endourology was more likely to discontinue early (adjusted HR 2.00, 95% CI 1.53-2.95, p <0.001), general urology was more likely to report results (adjusted OR 1.54, 95% CI 1.13-2.11, p=0.006) and andrology was less likely to publish (adjusted OR 0.53, 95% CI 0.35-0.81, p=0.003).

CONCLUSIONS

Sponsor type is significantly associated with trial completion and dissemination. Government-sponsored trials had the best performance, while industry and academic-sponsored trials lagged in completion and results reporting, respectively. Subspecialty played a lesser role. Lack of dissemination remains a problem for urology trials.

Panax ginseng clinical trials: Current status and future perspectives

Panax Ginseng has been widely used in Asian for thousand years. In order to evaluate the efficacy and safety of ginseng, more and more ginseng clinical trials (GCTs) have been conducted recently. However, there is a lack of an extensive review summarizing the current status for the quality and quantity of ginseng clinical researches until now. Therefore, clinical trials for ginseng were retrieved from International Clinical Trials Registration Platform and collected through the system retrieval method of Preferred Reporting Items for Systematic Reviews and Meta-Analyses in PubMed, the Web of Science, the Korean Studies Information Service System, and SCOPUS database. We summarized the clinical characteristics of 152 registered ginseng clinical trials (R-GCTs) and119 published ginseng clinical trials (P-GCTs), such as source register, recruitment status, primary purpose, duration, sample size, conditions, and outcomes. Among them, ginseng has mainly been studied in clinical trials in the single-center and less than 200 subjects. In the most GCTs, healthy subjects and patients with various conditions, such as cardiovascular and metabolic diseases are administrated with ginseng, ginsenosides or the prescriptions containing ginseng for less than 3 months to investigate the protective and therapeutic functions of ginseng. 95 (79.8 %) published articles showed that ginseng has plenty of positive effects. This review could assist the basic researchers and clinical doctors to understand current status and problem of ginseng clinical research, and perhaps could benefit for the reasonable and accurate design of future clinical studies.

Scientometric measures of prospectively registered clinical trials over time: A comparison of IRCT and ClinicalTrials.gov

Background: Iranian Registry of Clinical Trials (IRCT) started as a primary registry in 2008. We examined the characteristics and scientometric measures of prospectively registered clinical trials in IRCT over time and compared them with that of ClinicalTrials.gov. Methods: We selected eligible trial records between 2008 and 2016 from the IRCT database. We assessed their characteristics and the journal metrics of ensuing outputs over the study period and compared our findings with the corresponding information from ClinicalTrials.gov reported by Magdalena Zwierzyna et al. and a random sample of trials registered with this registry. We used the chi-square test for comparison of proportions and Mann-Whitney U test for comparison of medians. P-value <0.05 was considered statistically significant. Statistical analyses were performed using IBM SPSS Statistics V.22. Results: 1751 prospectively registered clinical trials were eligible for analysis, of which 1526 (87%) had parallel-group design, 1541 (88%) reported to be randomized, 753 (43%) used double-blinding design, 485 (%27.7) had sample size more than 100, 1313 (75%) completed within a year, 1539 (87.9%) were single centered and 1529 (87.3%) exclusively used public money. Comparison with ClinicalTrials.gov showed that they are less likely to have multiple centers, funded by private sectors, continue beyond one year; and more likely to be randomized, double-blind and get published as a paper. The sample sizes were similar. Journal scientometric measures remained constant over the study period for both databases but were higher in ClinicalTrials.gov (median SJR=1.67, IQR=1.1-3.23) compared with IRCT (median SJR=0.58, IQR=0.34-0.91). Conclusion: Our findings suggest that clinical trials registered in IRCT are predominantly investigator-initiated studies with acceptable methodological features and high publication rate albeit in journals with substantially lower scientometric measures compared with that of ClinicalTrials.gov. Journal metric indices remained constant despite an increase in the number of registrations in IRCT.

CTO: a Community-Based Clinical Trial Ontology and its Applications in PubChemRDF and SCAIView

Driven by the use cases of PubChemRDF and SCAIView, we have developed a first community-based clinical trial ontology (CTO) by following the OBO Foundry principles. CTO uses the Basic Formal Ontology (BFO) as the top level ontology and reuses many terms from existing ontologies. CTO has also defined many clinical trial-specific terms. The general CTO design pattern is based on the PICO framework together with two applications. First, the PubChemRDF use case demonstrates how a drug Gleevec is linked to multiple clinical trials investigating Gleevec's related chemical compounds. Second, the SCAIView text mining engine shows how the use of CTO terms in its search algorithm can identify publications referring to COVID-19-related clinical trials. Future opportunities and challenges are discussed.