Completeness and changes in registered data and reporting bias of randomized controlled trials in ICMJE journals after trial registration policy

Trials that turn from retrospectively registered to prospectively registered: a cohort study of "retroactively prospective" clinical trial registration using history data

BACKGROUND

Prospective registration of clinical trials is mandated by various regulations. However, clinical trial registries like ClinicalTrials.gov allow registry entries to be updated at any time, and key study elements, including the start date, may change before the first patient is enrolled. If a trial changes its start date after recruiting began, however, it may indicate a reason for concern. This study aimed to measure the rate of "retroactively prospective" trials. This refers to trials that are originally registered retrospectively, with the start date before the registration date, but that retroactively change their start date to be after the registration date, making them appear as if they were prospectively registered.

METHODS

We retrieved clinical trial history data for all clinical trials registered on ClinicalTrials.gov with a first registration date in the year 2015 (N = 11,908). Using automated analyses, we determined the timepoints of registration in relation to the start date of the trial over time. For retroactively prospective trials and a set of control trials, we manually checked the accompanying publications to determine which start date they report and whether they report changes to the start date.

RESULTS

We found 235 clinical trials to be retroactively prospective, comprising 2.0% of all clinical trials in our sample of 11,908 trials. Among the 113 retroactively prospective clinical trials with an accompanying publication, 12 (10.6%) explicitly stated in the publication that they had been prospectively registered.

CONCLUSIONS

Retroactively prospective trial registration happens in one in 50 trials. While these changes to the start date could be mistakes or legitimate edits based on the most up-to-date information, they could also indicate a retrospectively registered trial that has been made to appear as a prospectively registered trial, which would lead to biases unapparent to reviewers. Our results point to the need for more transparent reporting of changes to a trial's details and have implications for the review and conduct of clinical trials, with our fully automated and freely available tools allowing reviewers or editors to detect these changes.

TRIAL REGISTRATION

The preregistered protocol of our study is available via https://osf.io/rvq53 . The most recent version of the protocol lists all deviations from the original study plan, including the rationale behind the changes, and additional analyses that were conducted.

Estimating the prevalence of discrepancies between study registrations and publications: a systematic review and meta-analyses

OBJECTIVES

Prospectively registering study plans in a permanent time-stamped and publicly accessible document is becoming more common across disciplines and aims to reduce risk of bias and make risk of bias transparent. Selective reporting persists, however, when researchers deviate from their registered plans without disclosure. This systematic review aimed to estimate the prevalence of undisclosed discrepancies between prospectively registered study plans and their associated publication. We further aimed to identify the research disciplines where these discrepancies have been observed, whether interventions to reduce discrepancies have been conducted, and gaps in the literature.

DESIGN

Systematic review and meta-analyses.

DATA SOURCES

Scopus and Web of Knowledge, published up to 15 December 2019.

ELIGIBILITY CRITERIA

Articles that included quantitative data about discrepancies between registrations or study protocols and their associated publications.

DATA EXTRACTION AND SYNTHESIS

Each included article was independently coded by two reviewers using a coding form designed for this review (osf.io/728ys). We used random-effects meta-analyses to synthesise the results.

RESULTS

We reviewed k=89 articles, which included k=70 that reported on primary outcome discrepancies from n=6314 studies and, k=22 that reported on secondary outcome discrepancies from n=1436 studies. Meta-analyses indicated that between 29% and 37% (95% CI) of studies contained at least one primary outcome discrepancy and between 50% and 75% (95% CI) contained at least one secondary outcome discrepancy. Almost all articles assessed clinical literature, and there was considerable heterogeneity. We identified only one article that attempted to correct discrepancies.

CONCLUSIONS

Many articles did not include information on whether discrepancies were disclosed, which version of a registration they compared publications to and whether the registration was prospective. Thus, our estimates represent discrepancies broadly, rather than our target of undisclosed discrepancies between prospectively registered study plans and their associated publications. Discrepancies are common and reduce the trustworthiness of medical research. Interventions to reduce discrepancies could prove valuable.

REGISTRATION

osf.io/ktmdg. Protocol amendments are listed in online supplemental material A.

Unpublished completed obstetric randomized clinical trials registered at ClinicalTrials.gov: how big is this issue?

BACKGROUND

A portion of obstetrical randomized clinical trials registered on ClinicalTrials.gov are not published in peer-reviewed journals.

OBJECTIVE

This study aimed to compare the characteristics of completed published vs unpublished randomized clinical trials in obstetrics registered on ClinicalTrials.gov and to identify barriers to publication.

STUDY DESIGN

This cross-sectional study queried ClinicalTrials.gov for all completed obstetrical randomized clinical trials registered between January 1, 2009, and December 31, 2018. For each completed obstetrical randomized clinical trial, we abstracted the following registration fields from ClinicalTrials.gov: ClinicalTrials.gov identifier, recruitment status, trial start and completion dates, study results, type of intervention, study phase, enrollment size, funder type, location, and facilities. Calculated variables included time to completion. In May 2021, we used PubMed and Google Scholar to identify the publication status of completed trials, and we compared the characteristics of published vs unpublished randomized clinical trials. The corresponding authors' e-mail addresses for the unpublished studies were collected from ClinicalTrials.gov and departmental websites. Between September 2021 and March 2022, the authors of these completed but unpublished obstetrical randomized clinical trials were contacted and invited to respond to a survey examining perceptions of barriers to publication, responses of which were collected and presented as counts and percentages.

RESULTS

Of the 647 obstetrical randomized clinical trials marked as completed on ClinicalTrials.gov, 378 (58%) were published, and 269 (42%) were unpublished. Unpublished trials were more likely to have an enrollment size of <50 participants (14.5% published vs 25.3% unpublished; P<.001) and less likely to be conducted at multiple sites (25.4% published vs 17.5% unpublished; P<.02). The main barriers to publication reported in the survey by authors whose trials were not published included lack of time (30%), change in employment or completion of training (25%), and results that were not of statistical significance (15%).

CONCLUSION

Among the obstetrical randomized clinical trials registered and marked as completed on ClinicalTrials.gov, more than 40% were unpublished. Unpublished trials were more likely to be smaller studies, conducted by researchers who reported experiencing a lack of time as the most common barrier to study publication.

Transparency of clinical trials in pancreatic cancer: An analysis of availability of trial results from the ClinicalTrials.gov database

Background

Pancreatic cancer (PC) is a highly malignant tumor of the digestive system. As clinical trials involving PC are increasingly being conducted, the transparency of the generated data has become an important issue of concern. In other areas of medicine, clinical trial transparency presents a worrying state of affairs. However, at present, there has been no study examining the transparency of data derived from PC clinical trials.

Methods

A comprehensive search was conducted in the ClinicalTrial.gov database for clinical trials investigating pancreatic cancer as of June 2022. We examined the availability of clinical trial results and recorded the characteristics of the trials.

Results

A total of 856 trials were included in this study, of which 668 were completed and 188 were terminated or suspended. The results of 626 trials (73.13%) were available, of these 230 trials (26.87%) did not disclose any information on the trial data in any form. The publication rate for trials with available results was 86.10%, but the report rate on ClinicalTrial.gov was only 39.78%.

Conclusion

Although approximately 90% of clinical trial investigating interventions on patients with PC have published study results, 30% of trials did not report any findings, and the disclosure of trial results from ClinicalTrial.gov was unsatisfactory. In general, there is still room for improvement in the transparency of PC clinical trials.

Rotavirus vaccine clinical trials: a cross-sectional analysis of clinical trials registries

Background

Rotavirus is a primary infectious virus causing childhood diarrhoea and is associated with significant mortality in children. Three African countries (Nigeria, the Democratic Republic of Congo, and Angola) are among the five countries that account for 50% of all diarrheal-related deaths worldwide. This indicates that much needs to be done to reduce this burden. The World Health Organization International Clinical Trial Registry Platform (WHO ICTRP) is a global repository for primary registries reporting on clinical trials. This study aimed to identify and describe planned, ongoing, and completed rotavirus vaccine trials conducted globally.

Methods

We searched WHO-ICTRP on 17 June 2021 and conducted a cross-sectional analysis of rotavirus studies listed in the database. Data extraction included trial location, participant age, source of the trial record, trial phase, sponsor, and availability of results. We used the Microsoft Excel 365 package to generate descriptive summary statistics.

Results

We identified 242 rotavirus vaccine trials registered from 2004 to 2020. Most of these trials were registered retrospectively, with only 26% of the rotavirus vaccine trials reporting the availability of results in their registries. Most of the trials are studying children aged less than 5 years. The recruitment status for these trials is currently shown in the WHO-ICTRP as “not recruiting” for 80.17% of trials, “recruiting” for 11.57% of trials recruiting, and unknown for 6.61% of trials. The continents in which these rotavirus vaccine trials have recruitment sites in Asia (41%) and North America (20%), with the maximum number of trials in the clinical trial registries coming from India (21%) and the USA (11%) with most being sponsored by the pharmaceutical industry. Our analysis shows that only 26% of the rotavirus vaccine trials report the availability of results in their registries.

Conclusions

Mapping rotavirus vaccine clinical trial activity using data from the WHO ICTRP beneficial provides valuable information on planned, ongoing, or completed trials for researchers, funders, and healthcare decision-makers. Despite the high rotavirus disease burden in low- and middle-income countries, including Africa, there is minimal clinical trial activity related to the condition on the continent. The clinical trial registries as a valuable tool to share interim results of the trials.

From registration, protocol to report: are COVID-19-related RCTs in mainland China consistent? A systematic review of clinical trial registry and literature

OBJECTIVE

To provide a comprehensive review of registered COVID-19-related randomised controlled trials (RCTs) in mainland China and evaluate the transparency of reporting through comparison of registrations, protocols and full reports.

DESIGN

Systematic review of trial registrations and publications.

DATA SOURCES

International Clinical Trials Registry Platform, Chinese Clinical Trial Registry, ClinicalTrials.gov, the ISRCTN registry and EU Clinical Trial Register were accessed on 1 February 2022. Publications were searched in PubMed, Embase, Cochrane Library, Google Scholar, CNKI.net and Wanfangdata from 10 February 2022 to 12 February 2022.

ELIGIBILITY CRITERIA

Eligible trials were COVID-19 related RCTs carried out in mainland China. Observational studies, non-randomised trials and single-arm trials were excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data from registrations, publications and performed risk of bias assessment for trial reports. Information provided by registrations and publications was compared. The findings were summarised with descriptive statistics.

RESULTS

The number of eligible studies was 415. From these studies 20 protocols and 77 RCT reports were published. Seven trials published both protocol and RCT full report. Between registrations and publications, discrepancy or omission was found in sample size (7, 35.0% for protocols and 47, 61.0% for reports, same below), trial setting (13, 65.0% and 43, 55.8%), inclusion criteria (12, 60.0% and 57, 74.0%), exclusion criteria (10, 50.0% and 54, 70.1%), masking method (9, 45.0% and 35, 45.5%) and primary outcome or time frame of primary outcome measurement (14, 70.0% and 51, 66.2%). Between protocols and full reports, 5 (71.4%) reports had discrepancy in primary outcome or time frame of primary outcome measurement.

CONCLUSIONS

Discrepancy among registrations, protocols and reports revealed compromised transparency in reporting of COVID-19-related RCTs in mainland China. The importance of trial registration should be further emphasised to enhance transparent RCT reporting.

Transparency of results reporting for depression treatment studies in ClinicalTrials.gov: a cross-sectional study

OBJECTIVES

Depression affects an estimated 7% of the adult population at an estimated cost of over US$200 billion/year in the USA. Complete, transparent reporting of clinical trial data facilitates valid estimates of treatment efficacy. In the USA, ClinicalTrials.gov increases transparency through mandatory prospective trial registration and outcome reporting. We examined characteristics of the transparent reporting of depression treatment studies registered in ClinicalTrials.gov.

DESIGN

Cross sectional.

SETTING AND PARTICIPANTS

US-based studies identified in a search of ClinicalTrials.gov with depression as the condition, enrolling ages 18 and older, and completed between 1 January 2008 and 1 May 2019.

INTERVENTIONS

All interventions were included.

MAIN OUTCOMES AND MEASURES

The main outcome was whether any results were reported prior to 1 May 2020. Data were extracted regarding inclusion and exclusion criteria, publications related to the study and specification of hypotheses.

RESULTS

725 studies involving 156 634 patients met inclusion criteria. 416 (57.4%) of the studies posted some results. However, statistical test results were not included in 230 studies (55.3%). Most studies had data that could have been analysed and reported. Compared with studies without results, studies with any results were more likely to have hypotheses, include drug treatment conditions, and to have publications related to the study.

CONCLUSIONS

Required study registration does not always result in transparent outcome reporting. Better compliance with mandated reporting and improved reporting standards would facilitate a more comprehensive representation of depression treatment research.

Discrepancies between FDA documents and ClinicalTrials.gov for Orphan Drug-related clinical trial data

Clinical trial registries such as ClinicalTrials.gov (CTG) hold large amounts of data regarding trials. Drugs for rare diseases are known as orphan drugs (ODs), and it is particularly important that trials for ODs are registered, and the data in the trial record are accurate. However, there may be discrepancies between trial-related data that were the basis for the approval of a drug, as available from Food and Drug Administration (FDA) documents such as the Medical Review, and the data in CTG. We performed an audit of FDA-approved ODs, comparing trial-related data on phase, enrollment, and enrollment attribute (anticipated or actual) in such FDA documents and in CTG. The Medical Reviews of 63 ODs listed 422 trials. We used study identifiers in the Medical Reviews to find matches with the trial ID number, 'Other ID' or 'Acronyms' in CTG, and identified 202 trials that were registered with CTG. In comparing the phase data from the 'Table of Clinical Studies' of the Medical Review, with the data in CTG, there were exact matches in only 75% of the cases. The enrollment matched only in 70% of the cases, and the enrollment attribute in 91% of the cases. A similar trend was found for the sub-set of pivotal trials. Going forward, for all trials listed in a registry, it is important to provide the trial ID in the Medical Review. This will ensure that all trials that are the basis of a drug approval can be swiftly and unambiguously identified in CTG. Also, there continue to be discrepancies in trial data between FDA documents and CTG. Data in the trial records in CTG need to be updated when relevant.

Is mandatory prospective trial registration working? An update on the adherence to the International Committee of Medical Journal Editors guidelines across five psychiatry journals: 2015-2020

OBJECTIVE

Previous research indicated that the International Committee of Medical Journal Editors guidelines of prospective trial registration with clearly identified primary and secondary outcome measures are only adhered to in 14.4% of studies published in the top five psychiatry journals between 1 January 2009 and 31 July 2013. This study examined if adherence has improved.

METHODS

The registration information, article information, primary outcome measures (POMs), participant numbers and funding source were extracted from studies published in the same five psychiatry journals between 1 January 2015 and 31 December 2019. Discrepancies between POMs in the articles and registry were tracked.

RESULTS

Of the 7268 publications, 268 studies required registration. Three (1.1%) were unregistered, 107 (39.9%) were retrospectively registered, and 158 (58.9%) were prospectively registered. Of the 158 prospectively registered studies, 16 (10.1%) had unclear POMs in the article or registration, 22 (13.9%) had discrepancies between registered and published POMs, and 33 (20.9%) had no POM discrepancies but had retrospectively updated POMs in the registry. Of the 22 studies with discrepancies, nine (40.9%) were determined to favour statistically significant results. Overall, 87 (32.5%) of the 268 studies were prospectively registered with no discrepancies between registered and published POMs and no changes to registered POMs or timeframes.

CONCLUSION

Although this rate of one third of published articles fully adhering to the guidelines is an improvement compared to previous research, further efforts still need to be made by both authors and journals to ensure full transparency in the reporting of studies in psychiatry.

Agreement of primary outcomes in chiropractic-related clinical trials registered in clinicaltrials.gov with corresponding publication

INTRODUCTION

Previous analysis of registered clinical trials has found a number of protocols result in changes in the registered primary outcome measures. This investigation determined if reported primary outcomes in chiropractic-related clinical trials registered in clinicaltrials.gov match their published results. Additionally, we assessed secondary outcomes, publication status and whether raw data were posted to the registry.

METHODS

Clinicaltrials.gov was searched for chiropractic-related trials and having a completed status. If the study was published, outcome measures were compared between the clinicaltrials.gov entry and the published paper to assess for consistency.

RESULTS

Within clinicaltrials.gov 171 chiropracticrelated protocols were identified with 102 of those published (59.6% publication rate). Ninety-two of the published papers (90.2%) had agreement between their primary outcome and the entry on clinicaltrials.gov and 82 (80.4%) agreed with the secondary outcomes.

CONCLUSION

A modest rate of agreement between clinicaltrials.gov entries and the published papers was found. While chiropractic-related clinical trials are fewer compared to medical trials, chiropractic-related research has a substantially better rate of primary and secondary outcome concordance with registered protocols.

Systematic reviews that include only published data may overestimate the effectiveness of analgesic medicines for low back pain: a systematic review and meta-analysis

OBJECTIVE

Systematic reviews of analgesics for low back pain generally include published data only. Obtaining data from unpublished trials is potentially important because they may impact effect sizes in meta-analyses. We determined whether including unpublished data from trial registries changes the effect sizes in meta-analyses of analgesics for low back pain.

STUDY DESIGN AND SETTING

Trial registries were searched for unpublished data that conformed to the inclusion criteria of n = 5 individual source systematic reviews. We reproduced the meta-analyses using data available from the original reviews and then reran the same analyses with the addition of new unpublished data.

RESULTS

Sixteen completed, unpublished, trials were eligible for inclusion in four of the source reviews. Data were available for five trials. We updated the analyses for two of the source reviews. The addition of data from two trials reduced the effect size of muscle relaxants, compared with sham, for recent-onset low back pain from -21.71 (95% CI: -28.23 to -15.19) to -2.34 (95% CI: -3.34 to -1.34) on a 0-100 scale for pain intensity. The addition of data from three trials (one enriched design) reduced the effect size of opioid analgesics, compared with sham, for chronic low back pain from -10.10 (95% CI: -12.81 to -7.39) to -9.31 (95% CI: -11.51 to -7.11). The effect reduced in the subgroup of enriched design studies, from -12.40 (95% CI: -16.90 to -7.91) to -11.34 (95% CI: -15.36 to -7.32), and in the subgroup of nonenriched design studies, from -7.27 (95% CI: -9.97 to -4.57) to -7.19 (95% CI: -9.24 to -5.14).

CONCLUSION

Systematic reviews should include reports of unpublished trials. The result for muscle relaxants conflicts with the conclusion of the published review and recent international guidelines. Adding unpublished data strengthens the evidence that opioid analgesics have small effects on persistent low back pain and more clearly suggests these effects may not be clinically meaningful.

Prospective registration and reporting of trial number in randomised clinical trials: global cross sectional study of the adoption of ICMJE and Declaration of Helsinki recommendations

OBJECTIVES

To evaluate the compliance with prospective registration and inclusion of the trial registration number (TRN) in published randomised controlled trials (RCTs), and to analyse the rationale behind, and detect selective registration bias in, retrospective trial registration.

DESIGN

Cross sectional analysis.

DATA SOURCES

PubMed, the 17 World Health Organization's trial registries, University of Toronto library, International Committee of Medical Journal Editors (ICMJE) list of member journals, and the InCites Journal Citation Reports.

STUDY SELECTION CRITERIA

RCTs registered in any WHO trial registry and published in any PubMed indexed journal in 2018.

RESULTS

This study included 10 500 manuscripts published in 2105 journals. Overall, 71.2% (7473/10500) reported the TRN and 41.7% (3013/7218) complied with prospective trial registration. The univariable and multivariable analyses reported significant relations (P<0.05) between reporting the TRN and the impact factor and ICMJE membership of the publishing journal. A significant relation (P<0.05) was also observed between prospective trial registration and the registry, region, condition, funding, trial size, interval between paper registration and submission dates, impact factor, and ICMJE membership of the publishing journal. A manuscript published in an ICMJE member journal was 5.8 times more likely to include the TRN (odds ratio 5.8, 95% confidence interval 4.0 to 8.2), and a published trial was 1.8 times more likely to be registered prospectively (1.8, 1.5 to 2.2) when published in an ICMJE member journal compared with other journals. This study detected a new form of bias, selective registration bias, with a higher proportion (85.2% (616/723)) of trials registered retrospectively within a year of submission for publication. Higher rates of retrospective registrations were observed within the first three to eight weeks after enrolment of study participants. Within the 286 RCTs registered retrospectively and published in an ICMJE member journal, only 2.8% (8/286) of the authors included a statement justifying the delayed registration. Reasons included lack of awareness, error of omission, and the registration process taking longer than anticipated.

CONCLUSIONS

This study found a high compliance in reporting of the TRN for trial papers published in ICMJE member journals, but prospective trial registration was low.

Prevalence of Multiplicity and Appropriate Adjustments Among Cardiovascular Randomized Clinical Trials Published in Major Medical Journals

Importance

Multiple analyses in a clinical trial can increase the probability of inaccurately concluding that there is a statistically significant treatment effect. However, to date, it is unknown how many randomized clinical trials (RCTs) perform adjustments for multiple comparisons, the lack of which could lead to erroneous findings.

Objectives

To assess the prevalence of multiplicity and whether appropriate multiplicity adjustments were performed among cardiovascular RCTs published in 6 medical journals with a high impact factor.

Design, Setting, and Participants

In this cross-sectional study, cardiovascular RCTs were selected from all over the world, characterized as North America, Western Europe, multiregional, and rest of the world. Data were collected from past issues of 3 cardiovascular journals (Circulation, European Heart Journal, and Journal of the American College of Cardiology) and 3 general medicine journals (JAMA, The Lancet, and The New England Journal of Medicine) with high impact factors published between August 1, 2015, and July 31, 2018. Supplements and trial protocols of each of the included RCTs were also searched for multiplicity. Data were analyzed December 20 to 27, 2018.

Exposures

Data from the selected RCTs were extracted and verified independently by 2 researchers using a structured data instrument. In case of disagreement, a third reviewer helped to achieve consensus. An RCT was considered to have multiple treatment groups if it had more than 2 arms; multiple outcomes were defined as having more than 1 primary outcome, and multiple analyses were defined as analysis of the same outcome variable in multiple ways. Multiplicity was examined only for the analysis of the primary end point.

Main Outcomes and Measures

Outcomes of interest were percentages of primary analyses that performed multiplicity adjustment of primary end points.

Results

Of 511 cardiovascular RCTs included in this analysis, 300 (58.7%) had some form of multiplicity; of these 300, only 85 (28.3%) adjusted for multiplicity. Intervention type and funding source had no statistically significant association with the reporting of multiplicity risk adjustment. Trials that assessed mortality vs nonmortality outcomes were more likely to contain a multiplicity risk in their primary analysis (66.3% [177 of 267] vs 50.4% [123 of 244]; P < .001), and larger trials vs smaller trials were less likely to make any adjustments for multiplicity (35.6% [52 of 146] vs 21.4% [33 of 154]; P = .001).

Conclusions and Relevance

Findings from this study suggest that cardiovascular RCTs published in medical journals with high impact factors demonstrate infrequent adjustments to correct for multiple comparisons in the primary end point. These parameters may be improved by more standardized reporting.

Addressing Publication Bias in Meta-Analysis

Abstract. Meta-analyses are an indispensable research synthesis tool for characterizing bodies of literature and advancing theories. One important open question concerns the inclusion of unpublished data into meta-analyses. Finding such studies can be effortful, but their exclusion potentially leads to consequential biases like overestimation of a literature’s mean effect. We address two questions about unpublished data using MetaLab, a collection of community-augmented meta-analyses focused on developmental psychology. First, we assess to what extent MetaLab datasets include gray literature, and by what search strategies they are unearthed. We find that an average of 11% of datapoints are from unpublished literature; standard search strategies like database searches, complemented with individualized approaches like including authors’ own data, contribute the majority of this literature. Second, we analyze the effect of including versus excluding unpublished literature on estimates of effect size and publication bias, and find this decision does not affect outcomes. We discuss lessons learned and implications.

Trial registration as a safeguard against outcome reporting bias and spin? A case study of randomized controlled trials of acupuncture

BACKGROUND AND OBJECTIVE

Trial registration is widely endorsed as it is considered not only to enhance transparency and quality of reporting but also to help safeguard against outcome reporting bias and probably spin, known as specific reporting that could distort the interpretation of results thus mislead readers. We planned to investigate the current registration status of recently published randomized controlled trials (RCTs) of acupuncture, outcome reporting bias in the prospectively registered trials, and the association between trial registration and presence of spin and methodological factors in acupuncture RCTs.

METHODS

Acupuncture RCTs published in English in recent 5 years (January 2013 to December 2017) were searched in PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Trial registration records identified in the publications and trial registries were classified into prospectively registered, retrospectively registered, or unregistered. Primary outcomes were identified and the direction of the results was judged as statistically significant (positive) or statistically nonsignificant (negative). We compared registered and published primary outcomes to assess outcome reporting bias and assessed whether discrepancies favored statistically significant outcomes. Frequency and strategies of spin in published reports with statistically nonsignificant results for primary outcomes were then identified. We also analyzed whether the trial registration status was associated with spin and quality of methodological factors.

RESULTS

Of the 322 included RCTs, 41.9% (n = 135) were prospectively registered. Among 64 studies that were prospectively registered and specified primary outcomes, 25 trials had the discrepancies between the registered and published primary outcomes and 60% of them (15 trials) favored the statistically significant findings. Among 169 studies that specified primary outcomes, trial registration status was not associated with the direction of results, i.e., statistically significant or not. Spin was identified in 56.4% out of 78 studies with statistically nonsignificant primary outcomes and claiming efficacy with no consideration of statistically nonsignificant primary outcomes was the most common strategy for spin. Trial registration status was not statistically different between studies with and without spin.

CONCLUSION

While trial registration seemed to have improved over time, primary outcomes in registered records and publications were often inconsistent, tending to favor statistically significant findings and spin was common in studies with statistically nonsignificant primary outcomes. Journal editors and researchers in this field should be alerted to still prevalent reporting bias and spin.

Endorsement of reporting guidelines and study registration by endocrine and internal medicine journals: meta-epidemiological study

OBJECTIVES

To improve the trustworthiness of evidence, studies should be prospectively registered and research reports should adhere to existing standards. We aimed to systematically assess the degree to which endocrinology and internal medicine journals endorse study registration and reporting standards for randomised controlled trials (RCTs), systematic reviews (SRs) and observational studies (ObS). Additionally, we evaluated characteristics that predict endorsement of reporting or registration mechanism by these journals.

DESIGN

Meta-epidemiological study.

SETTING

Journals included in the 'Endocrinology and Metabolism' and 'General and Internal Medicine' 2017 Journal Citation Reports.

PARTICIPANTS

Journals with an impact factor of ≥1.0, focused on clinical medicine, and those who publish RCTs, SRs and ObS were included.

PRIMARY OUTCOMES

Requirement of adherence to reporting guideline and study registration as determined from the journals' author instructions.

RESULTS

Of the 170 (82 endocrinology and 88 internal medicine) eligible journals, endorsing of reporting standards was the highest for RCTs, with 35 (43%) of endocrine journals and 55 (63%) of internal medicine journals followed by SRs, with 21 (26%) and 48 (55%), respectively, and lastly, by ObS with 41 (50%) of endocrine journals and 21 (24%) of internal medicine journals. In 78 (46%) journals RCTs were required to be registered and published in adherence to the Consolidated Standards of Reporting Trials statement. Only 11 (6%) journals required registration of SRs. Internal medicine journals were more likely to endorse reporting guidelines than endocrine journals except for Strengthening the Reporting of Observational Studies in Epidemiology. No other journal characteristic proved to be an independent predictor of reporting standard endorsement for RCTs besides trial registration.

CONCLUSION

Our results highlight that study registration requirement and reporting guideline endorsement are suboptimal in internal medicine and endocrine journals. This malpractice may be further enhanced since endorsement does not imply enforcement, impairing the practice of evidence-based medicine.

An empirical assessment of research practices across 163 clinical trials of tumor-bearing companion dogs

Comparative clinical trials of domestic dogs with spontaneously-occurring cancers are increasingly common. Canine cancers are likely more representative of human cancers than induced murine tumors. These trials could bridge murine models and human trials and better prioritize drug candidates. Such investigations also benefit veterinary patients. We aimed to evaluate the design and reporting practices of clinical trials containing ≥2 arms and involving tumor-bearing dogs. 163 trials containing 8552 animals were systematically retrieved from PubMed (searched 1/18/18). Data extracted included sample sizes, response criteria, study design, and outcome reporting. Low sample sizes were prevalent (median n = 33). The median detectable hazard ratio was 0.3 for overall survival and 0.06 for disease progression. Progressive disease thresholds for studies that did not adopt VCOG-RECIST guidelines varied in stringency. Additionally, there was significant underreporting across all Cochrane risk of bias categories. The proportion of studies with unclear reporting ranged from 44% (randomization) to 94% (selective reporting). 72% of studies also failed to define a primary outcome. The present study confirms previous findings that clinical trials in dogs need to be improved, particularly regarding low statistical power and underreporting of design and outcomes.

Correcting duplicate publications: follow up study of MEDLINE tagged duplications

Introduction

As MEDLINE indexers tag similar articles as duplicates even when journals have not addressed the duplication(s), we sought to determine the reasons behind the tagged duplications, and if the journals had undertaken or had planned to undertake any actions to address them.

Materials and methods

On 16 January 2013, we extracted all tagged duplicate publications (DPs), analysed published notices, and then contacted MEDLINE and editors regarding cases unaddressed by notices. For non-respondents, we compared full text of the articles. We followed up the study for the next 5 years to see if any changes occurred.

Results

We found 1011 indexed DPs, which represented 555 possible DP cases (in MEDLINE, both the original and the duplicate are assigned a DP tag). Six cases were excluded as we could not obtain their full text. Additional 190 (35%) cases were incorrectly tagged as DPs. Of 359 actual cases of DPs, 200 (54%) were due to publishers’ actions (e.g. identical publications in the same journal), and 159 (46%) due to authors’ actions (e.g. article submission to more than one journal). Of the 359 cases, 185 (52%) were addressed by notices, but only 25 (7%) retracted. Following our notifications, MEDLINE corrected 138 (73%) incorrectly tagged cases, and editors retracted 8 articles.

Conclusions

Despite clear policies on how to handle DPs, just half (54%) of the DPs in MEDLINE were addressed by journals and only 9% retracted. Publishers, editors, and indexers need to develop and implement standards for better correction of duplicate published records.

Trial registration in pediatric surgery trials

BACKGROUND

Prospective clinical trial registration serves to increase transparency and to mitigate selective reporting bias. An assessment of adult surgical trials revealed poor trial registration practice with incomplete provision of information in registries and inconsistent information in the corresponding publication. The extent and completeness of pediatric surgical trial registration are unknown. We aimed to determine the proportion and adequacy of clinical trial registration in pediatric surgery trials published in 2014.

METHODS

Using sensitive search strategies in MEDLINE, abstracts and full-texts of prospective pediatric intervention studies published in 2014 were screened in duplicate. Pediatric surgical trials were included. Clinical trial registration numbers obtained from publications were searched in trial registries. Data were extracted based on WHO 20-item minimum data set to determine the completeness of registration data. The proportion of registered trials was recorded and registration data were compared to reported data in the corresponding publication.

RESULTS

Our search and abstract screening identified 3375 articles for full text review. Following coding, a total of 54 pediatric surgical trials were included and analyzed; 28% (15/54) of which published a registration number. In trials which reported a registration number, 40% (6/15) were retrospectively registered and 40% (6/15) had made changes to their registered primary and/or secondary outcome measures. One included published trial reported an incorrect registration number.

CONCLUSIONS

Analysis of pediatric surgery trials published in 2014 revealed a poor prospective trial registration rate and incomplete registration data. Our study supports future initiatives for improved registration behaviors in pediatric surgery trials to ensure high-quality, transparent, reproducible evidence is generated.

STUDY TYPE

Therapeutic (clinical trials), level II.

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

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

Clinical trial registration in fertility trials - a case for improvement?

STUDY QUESTION

What is the prevalence and source of prospectively and retrospectively registered and unregistered trials in fertility treatments?

SUMMARY ANSWER

Trial registration is low and does not appear to be changing over the 5 years studied.

WHAT IS KNOWN ALREADY

Trial registration is associated with lower risk of bias than in unregistered trials.

STUDY DESIGN, SIZE, DURATION

The Cochrane Gynaecology and Fertility Group's specialised register was searched on 5 November 2015 for randomised controlled trials (RCTs) published from January 2010 to December 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible trials included randomised women or men for fertility treatments, were published in full text, and written in English. Two reviewers independently assessed trial registration status for each trial, by searching the publication, trial registries, and by contacting the original authors.

MAIN RESULTS AND ROLE OF CHANCE

Of 693 eligible RCTS, only 44% were registered trials. Of 309 registered trials, 21.7% were prospectively registered, 15.8% were registered within 6 months of first patient enrolment and 62.5% were retrospectively registered trials. Prospective trial registration by country varied from 0% to 100%. The highest frequency of prospective trial registration amongst the top 10 publishing countries was 31% in the Netherlands.

LIMITATIONS, REASONS FOR CAUTION

Only English language trials were included in this review.

WIDER IMPLICATIONS OF THE FINDINGS

Prospective trial registration is still low. Journals, funders and ethics committees could have a greater role to increase trial registration.

STUDY FUNDING/COMPETING INTERESTS

University of Auckland. No competing interests.

Clinical trial registration and reporting: a survey of academic organizations in the United States

BACKGROUND

Many clinical trials conducted by academic organizations are not published, or are not published completely. Following the US Food and Drug Administration Amendments Act of 2007, "The Final Rule" (compliance date April 18, 2017) and a National Institutes of Health policy clarified and expanded trial registration and results reporting requirements. We sought to identify policies, procedures, and resources to support trial registration and reporting at academic organizations.

METHODS

We conducted an online survey from November 21, 2016 to March 1, 2017, before organizations were expected to comply with The Final Rule. We included active Protocol Registration and Results System (PRS) accounts classified by ClinicalTrials.gov as a "University/Organization" in the USA. PRS administrators manage information on ClinicalTrials.gov. We invited one PRS administrator to complete the survey for each organization account, which was the unit of analysis.

RESULTS

Eligible organization accounts (N = 783) included 47,701 records (e.g., studies) in August 2016. Participating organizations (366/783; 47%) included 40,351/47,701 (85%) records. Compared with other organizations, Clinical and Translational Science Award (CTSA) holders, cancer centers, and large organizations were more likely to participate. A minority of accounts have a registration (156/366; 43%) or results reporting policy (129/366; 35%). Of those with policies, 15/156 (11%) and 49/156 (35%) reported that trials must be registered before institutional review board approval is granted or before beginning enrollment, respectively. Few organizations use computer software to monitor compliance (68/366; 19%). One organization had penalized an investigator for non-compliance. Among the 287/366 (78%) accounts reporting that they allocate staff to fulfill ClinicalTrials.gov registration and reporting requirements, the median number of full-time equivalent staff is 0.08 (interquartile range = 0.02-0.25). Because of non-response and social desirability, this could be a "best case" scenario.

CONCLUSIONS

Before the compliance date for The Final Rule, some academic organizations had policies and resources that facilitate clinical trial registration and reporting. Most organizations appear to be unprepared to meet the new requirements. Organizations could enact the following: adopt policies that require trial registration and reporting, allocate resources (e.g., staff, software) to support registration and reporting, and ensure there are consequences for investigators who do not follow standards for clinical research.

Conditional equivalence testing: An alternative remedy for publication bias

We introduce a publication policy that incorporates "conditional equivalence testing" (CET), a two-stage testing scheme in which standard NHST is followed conditionally by testing for equivalence. The idea of CET is carefully considered as it has the potential to address recent concerns about reproducibility and the limited publication of null results. In this paper we detail the implementation of CET, investigate similarities with a Bayesian testing scheme, and outline the basis for how a scientific journal could proceed to reduce publication bias while remaining relevant.

Underregistration and Underreporting of Stem Cell Clinical Trials in Neurological Disorders

Background and Purpose

Research on stem cells (SC) is growing rapidly in neurology, but clinical applications of SC for neurological disorders remain to be proven effective and safe. Human clinical trials need to be registered in registries in order to reduce publication bias and selective reporting.

Methods

We searched three databases—clinicaltrials.gov, the Clinical Research Information System (CRIS), and PubMed—for neurologically relevant SC-based human trials and articles in Korea. The registration of trials, posting and publication of results, and registration of published SC articles were examined.

Results

There were 17 completed trials registered at clinicaltrials.gov and the CRIS website, with results articles having been published for 5 of them. Our study found 16 publications, of which 1 was a review article, 1 was a protocol article, and 8 contained registered trial information.

Conclusions

Many registered SC trials related to neurological disorders are not reported, while many SC-related publications are not registered in a public registry. These results support the presence of biased reporting and publication bias in SC trials related to neurological disorders in Korea.

Prevalence of clinical trial status discrepancies: A cross-sectional study of 10,492 trials registered on both ClinicalTrials.gov and the European Union Clinical Trials Register

OBJECTIVE

Trial registries are a key source of information for clinicians and researchers. While building OpenTrials, an open database of public trial information, we identified errors and omissions in registries, including discrepancies between descriptions of the same trial in different registries. We set out to ascertain the prevalence of discrepancies in trial completion status using a cohort of trials registered on both the European Union Clinical Trials Register (EUCTR) and ClinicalTrials.gov.

STUDY DESIGN AND SETTING

We used matching titles and registry IDs provided by both registries to build a cohort of dual-registered trials. Completion statuses were compared; we calculated descriptive statistics on the prevalence of discrepancies.

RESULTS

11,988 dual-registered trials were identified. 1,496 did not provide a comparable completion status, leaving 10,492 trials. 16.2% were discrepant on completion status. The majority of discrepancies (90.5%) were a 'completed' trial on ClinicalTrials.gov inaccurately marked as 'ongoing' on EUCTR. Overall, 33.9% of dual-registered trials described as 'ongoing' on EUCTR were listed as 'completed' on ClinicalTrials.gov.

CONCLUSION

Completion status on registries is commonly inaccurate. Previous work on publication bias may underestimate non-reporting. We describe simple steps registry owners and trialists could take to improve accuracy.

Comparison of reporting phase III randomized controlled trials of antibiotic treatment for common bacterial infections in ClinicalTrials.gov and matched publications

OBJECTIVES

Discrepancies between ClinicalTrials.gov entries and matching publications were previously described in general medicine. We aimed to evaluate the consistency of reporting in trials addressing systemic antibiotic therapy.

METHODS

We searched ClinicalTrials.gov for completed phase III trials comparing antibiotic regimens until May 2017. Matched publications were identified in PubMed. Two independent reviewers extracted data and identified inconsistencies. Reporting was assessed among studies started before and after 1 July 2005, when the International Committee of Medical Journal Editors (ICMJE) required mandatory registration as a prerequisite for considering a trial for publication.

RESULTS

Matching publications were identified for 75 (70%) of 107 ClinicalTrials.gov entries. Median time from study completion to publication was 26 months (interquartile range 19-42). Primary outcome definition was inconsistent between ClinicalTrials.gov and publications in seven trials (7/72, 10%) and reporting of the primary outcome timeframe was inconsistent in 14 (14/71, 20%). Secondary outcomes definitions were inconsistent in 36 trials (36/66, 55%). Reporting of inclusion criteria and study timeline were inconsistent in 17% (13/65) and 3% (2/65), respectively. Trials started after July 2005 were significantly less likely to have reporting inconsistencies and were published in higher impact factor journals.

CONCLUSIONS

We found a lower inconsistency rate of outcome reporting compared with other medical disciplines. Reporting completeness and consistency were significantly better after July 2005. The ICMJE requirement for mandatory registration was associated with significant improvement in reporting quality in infectious diseases trials. Prolonged time lag to publication and missing data from unpublished trials should raise a discussion on current reporting and publishing procedures.

Neuraminidase inhibitors for influenza: a systematic review and meta-analysis of regulatory and mortality data

BACKGROUND

Neuraminidase inhibitors (NIs) are stockpiled and recommended by public health agencies for treating and preventing seasonal and pandemic influenza. They are used clinically worldwide.

OBJECTIVES

To (1) describe the potential benefits and harms of NIs for influenza in all age groups by reviewing all clinical study reports (CSRs) of published and unpublished randomised, placebo-controlled trials and regulatory comments; and (2) determine the effect of oseltamivir (Tamiflu(®), Roche) treatment on mortality in patients with 2009A/H1N1 influenza.

METHODS

We searched trial registries, electronic databases and corresponded with regulators and sponsors to identify randomised trials of NIs. We requested full CSRs and accessed regulators' comments. We included only those trials for which we had CSRs. To examine the effects of oseltamivir on 2009A/H1N1 influenza mortality, we requested individual patient data (IPD) from corresponding authors of all included observational studies.

RESULTS

Effect of oseltamivir and zanamivir (Relenza®, GlaxoSmithKline) in the prevention and treatment of influenza: Oseltamivir reduced the time to first alleviation of symptoms in adults by 16.8 hours [95% confidence interval (CI) 8.4 to 25.1 hours]. Zanamivir reduced the time to first alleviation of symptoms in adults by 0.60 days (95% CI 0.39 to 0.81 days). Oseltamivir reduced unverified pneumonia in adult treatment [risk difference (RD) 1.00%, 95% CI 0.22% to 1.49%]; similar findings were observed with zanamivir prophylaxis in adults (RD 0.32%, 95% CI 0.09% to 0.41%). Oseltamivir treatment of adults increased the risk of nausea (RD 3.66%, 95% CI 0.90% to 7.39%) and vomiting (RD 4.56%, 95% CI 2.39% to 7.58%). In the treatment of children, oseltamivir induced vomiting (RD 5.34%, 95% CI 1.75% to 10.29%). Both oseltamivir and zanamivir prophylaxis reduced the risk of symptomatic influenza in individuals (oseltamivir RD 3.05%, 95% CI 1.83% to 3.88%; zanamivir RD 1.98%, 95% CI 0.98% to 2.54%) and in households (oseltamivir RD 13.6%, 95% CI 9.52% to 15.47%; zanamivir RD 14.84%, 95% CI 12.18% to 16.55%). Oseltamivir increased psychiatric adverse events in the combined on- and off-treatment periods (RD 1.06%, 95% CI 0.07% to 2.76%) and the risk of headaches while on treatment (RD 3.15%, 95% CI 0.88% to 5.78%). Effect of oseltamivir on mortality in patients with 2009A/H1N1 influenza: Analysis of summary data of 30 studies as well as IPD of four studies showed evidence of time-dependent bias. After adjusting for time-dependent bias and potential confounding variables, competing risks analysis of the IPD showed insufficient evidence that oseltamivir reduced the risk of mortality (hazard ratio 1.03, 95% CI 0.64 to 1.65).

CONCLUSIONS

Oseltamivir and zanamivir cause small reductions in the time to first alleviation of influenza symptoms in adults. The use of oseltamivir increases the risk of nausea, vomiting, psychiatric events in adults and vomiting in children. Oseltamivir has no protective effect on mortality among patients with 2009A/H1N1 influenza. Prophylaxis with either NI may reduce symptomatic influenza in individuals and in households. The balance between benefits and harms should be considered when making decisions about use of NIs for either prophylaxis or treatment of influenza.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002245.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Primary outcome switching among drug trials with and without principal investigator financial ties to industry: a cross-sectional study

OBJECTIVES

To determine the relationship between manufacturer-related financial ties among investigators of published drug trials and rates of discrepant registered and published primary trial outcomes.

DESIGN

Cross-sectional study.

SETTING

Human subjects drug trials published in 'core clinical' MEDLINE journals in 2013.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary study endpoint was the presence of a prospectively registered, clearly defined primary outcome that matched the published primary outcome for each included trial. Secondary outcomes included assessments of registration timing and quality, and the impact of outcome discrepancies between registration and publication on the statistical significance of the included trials.

RESULTS

Of 192 included trials, 134 (70%) were positive and 58 (30%) were negative. Financial ties were present between first or last authors and drug manufacturers for 130 trials (68%), of which 78% were positive, versus 53% of trials with no financial ties that were positive. Clearly defined, prospectively registered outcomes that matched the published outcomes were present in just 76 of the 192 trials (40%). After adjusting for study start date and sample size, the observed relationship between investigator financial ties and the presence of a match between prospectively registered and published primary outcomes was of borderline statistical significance (OR 2.12, 95% CI 0.998 to 4.50). Studies with financial ties present were more likely than studies without ties to have been prospectively registered (78%vs48%, P<0.001) and were more likely to have prospectively registered a clearly defined primary outcome(62%vs35%, P<0.001).

CONCLUSIONS

Less than half of the trials in this cohort were prospectively registered with a clear primary outcome that was consistent with the primary outcome reported in the published manuscript. The presence of investigator financial ties was associated with higher quality registration practices, though this association diminished after adjusting for factors that impact registration quality.

The Conduct and Reporting of Child Health Research: An Analysis of Randomized Controlled Trials Published in 2012 and Evaluation of Change over 5 Years

OBJECTIVES

For child health randomized controlled trials (RCTs) published in 2012, we aimed to describe design and reporting characteristics and evaluate changes since 2007; assess the association between trial design and registration and risk of bias (RoB); and assess the association between RoB and effect size.

STUDY DESIGN

For 300 RCTs, we extracted design and reporting characteristics and assessed RoB. We assessed 5-year changes in design and reporting (based on 300 RCTs we had previously analyzed) using the Fisher exact test. We tested for associations between design and reporting characteristics and overall RoB and registration using the Fisher exact, Cochran-Armitage, Kruskal-Wallis, and Jonckheere-Terpstra tests. We pooled effect sizes and tested for differences by RoB using the χ² test for subgroups in meta-analysis.

RESULTS

The 2012 and 2007 RCTs differed with respect to many design and reporting characteristics. From 2007 to 2012, RoB did not change for random sequence generation and improved for allocation concealment (P < .001). Fewer 2012 RCTs were rated high overall RoB and more were rated unclear (P = .03). Only 7.3% of 2012 RCTs were rated low overall RoB. Trial registration doubled from 2007 to 2012 (23% to 46%) (P < .001) and was associated with lower RoB (P = .009). Effect size did not differ by RoB (P = .43) CONCLUSIONS: Random sequence generation and allocation concealment were not often reported, and selective reporting was prevalent. Measures to increase trialists' awareness and application of existing reporting guidance, and the prospective registration of RCTs is needed to improve the trustworthiness of findings from this field.

Agreement in reporting between trial publications and current clinical trial registry in high impact journals: A methodological review

OBJECTIVES

The primary objective of this systematic survey was to examine the percentage of studies in which there was agreement in the reporting of the primary outcome between the currently updated version of the clinical trial registry and the published paper. We also investigated the factors associated with agreement in reporting of the primary outcome.

METHODS

We searched PubMed for all randomized control trials (RCT)s published in 2012-2015 in the top five general medicine journals (based on the 2014 impact factor). Two hundred abstracts (50 from each year) were randomly selected for data extraction. Agreement in reporting of 11 key study conduct items (e.g., sample size) and study characteristics (e.g., funding, number of sites) were extracted by two independent reviewers.

ANALYSIS

Descriptive analyses were conducted to determine the proportion of studies on which there was agreement in reporting of key study conduct items. Generalized estimating equations were used to explore factors associated with agreement in reporting of the primary outcome.

RESULTS

Of the 200 included studies, 87% had agreement in reporting of the primary outcome. After adjusting for other covariates, having greater than 50 sites was associated with an increased likelihood of agreement in reporting of the primary outcome (odds ratio=7.1, 95% confidence interval=1.39, 36.27, p=0.018).

CONCLUSIONS

We identified substantive disagreement in reporting between publications and current clinical trial registry, which were associated with several study characteristics. Further measures are needed to improve reporting given the potential threats to the quality and integrity of scientific research.

Outcome reporting bias in randomized-controlled trials investigating antipsychotic drugs

Recent literature hints that outcomes of clinical trials in medicine are selectively reported. If applicable to psychotic disorders, such bias would jeopardize the reliability of randomized clinical trials (RCTs) investigating antipsychotics and thus their extrapolation to clinical practice. We therefore comprehensively examined outcome reporting bias in RCTs of antipsychotic drugs by a systematic review of prespecified outcomes on ClinicalTrials.gov records of RCTs investigating antipsychotic drugs in schizophrenia and schizoaffective disorder between 1 January 2006 and 31 December 2013. These outcomes were compared with outcomes published in scientific journals. Our primary outcome measure was concordance between prespecified and published outcomes; secondary outcome measures included outcome modifications on ClinicalTrials.gov after trial inception and the effects of funding source and directionality of results on record adherence. Of the 48 RCTs, 85% did not fully adhere to the prespecified outcomes. Discrepancies between prespecified and published outcomes were found in 23% of RCTs for primary outcomes, whereas 81% of RCTs had at least one secondary outcome non-reported, newly introduced, or changed to a primary outcome in the respective publication. In total, 14% of primary and 44% of secondary prespecified outcomes were modified after trial initiation. Neither funding source (P=0.60) nor directionality of the RCT results (P=0.10) impacted ClinicalTrials.gov record adherence. Finally, the number of published safety endpoints (N=335) exceeded the number of prespecified safety outcomes by 5.5 fold. We conclude that RCTs investigating antipsychotic drugs suffer from substantial outcome reporting bias and offer suggestions to both monitor and limit such bias in the future.

Selective outcome reporting in obesity clinical trials: a cross-sectional review

Selective outcome reporting is a form of bias resulting from discrepancies between outcomes presented in a trial's registration and the published report. We investigate this selective bias in obesity clinical trials. A PubMed search was conducted to identify randomized controlled trials (RCTs) published in four obesity journals from 2013 to 2015. Primary, secondary and tertiary outcomes were recorded for each trial and compared to pre-specified outcomes in each trial's registration. Of the 392 identified articles, 142 were included in the final analysis; 22 (15%) RCTs demonstrated major outcome discrepancies between registration and publication: No primary outcomes were demoted to a secondary or tertiary outcome; 14 (36.84%) primary outcomes were omitted; 14 (36.84%) primary outcomes were added: 5 (13.16%) secondary outcomes were upgraded to primary outcomes; and timing of assessment for a primary outcome changed 5 (13.16%) times. Out of the 63 prospectively registered studies, 53 had no discrepancies. A total of 76 of the studies (29.80%) were unregistered or did not have an associated registration number. Our results suggest that selective outcome reporting may be a concern in obesity clinical trials. As selective outcome reporting may distort clinical findings and limit outcomes in systematic reviews, we encourage trialists and journal editors to work towards solutions to mitigate this issue.

A systematic review of the processes used to link clinical trial registrations to their published results

BACKGROUND

Studies measuring the completeness and consistency of trial registration and reporting rely on linking registries with bibliographic databases. In this systematic review, we quantified the processes used to identify these links.

METHODS

PubMed and Embase databases were searched from inception to May 2016 for studies linking trial registries with bibliographic databases. The processes used to establish these links were categorised as automatic when the registration identifier was available in the bibliographic database or publication, or manual when linkage required inference or contacting of trial investigators. The number of links identified by each process was extracted where available. Linear regression was used to determine whether the proportions of links available via automatic processes had increased over time.

RESULTS

In 43 studies that examined cohorts of registry entries, 24 used automatic and manual processes to find articles; 3 only automatic; and 11 only manual (5 did not specify). Twelve studies reported results for both manual and automatic processes and showed that a median of 23% (range from 13 to 42%) included automatic links to articles, while 17% (range from 5 to 42%) of registry entries required manual processes to find articles. There was no evidence that the proportion of registry entries with automatic links had increased (R ² = 0.02, p = 0.36). In 39 studies that examined cohorts of articles, 21 used automatic and manual processes; 9 only automatic; and 2 only manual (7 did not specify). Sixteen studies reported numbers for automatic and manual processes and indicated that a median of 49% (range from 8 to 97%) of articles had automatic links to registry entries, and 10% (range from 0 to 28%) required manual processes to find registry entries. There was no evidence that the proportion of articles with automatic links to registry entries had increased (R ² = 0.01, p = 0.73).

CONCLUSIONS

The linkage of trial registries to their corresponding publications continues to require extensive manual processes. We did not find that the use of automatic linkage has increased over time. Further investigation is needed to inform approaches that will ensure publications are properly linked to trial registrations, thus enabling efficient monitoring of trial reporting.

Responsible Translation of Stem Cell Research: An Assessment of Clinical Trial Registration and Publications

We assessed the extent to which the publication of clinical trial results of innovative cell-based interventions reflects International Society for Stem Cell Research best practice guidelines. We assessed: (1) characteristics and time to publication of completed trials; (2) quality of reported trials; and (3) results of published trials. We identified and analyzed publications from 1,052 novel stem cell clinical trials: 179 (45.4%) of 393 completed trials had published results; 48 trials were registered by known stem cell tourism clinics, none of which reported results. Completed non-industry-sponsored trials initially published more rapidly, but differences with industry-sponsored trials decreased over time. Most publications reported safety, and 67.3% (mainly early-stage trials) reported positive outcomes. A higher proportion of industry trials reported positive efficacy. Heightened patient expectations for stem cell therapies give rise to ethical obligations for the transparent conduct of clinical trials. Reporting guidelines need to be developed that are specific to early-phase clinical trials.

Registration status and methodological reporting of randomized controlled trials in obesity research: A review

OBJECTIVE

To assess registration and reporting details of randomized controlled trials (RCTs) published from 2011 to 2016 across four obesity journals.

METHODS

All issues from four leading obesity journals were searched systematically for RCTs from January 2011 to June 2016. Data on registration status were extracted from manuscripts, online trial registries, and a trial database; corresponding authors were contacted for registration details, when necessary. The methodological reporting of RCTs was assessed on specific criteria from the Consolidated Standards of Reporting Trials.

RESULTS

A total of 223 RCTs were reviewed. Three-quarters (n = 170) were registered publicly; 94 (55.3%) reported registration details in the manuscript, and 82 (48.2%) were registered prospectively. Newer RCTs were more likely to be registered prospectively than older RCTs (2014-2016: 57.3% vs. 2011-2013: 39.2%; c²  = 5.5, P = 0.02). Assessment on the Consolidated Standards of Reporting Trials demonstrated that less than half of all studies reported data collection dates (n = 108; 48.4%) or included "randomized trial" in the title (n = 89; 39.9%).

CONCLUSIONS

The methodological reporting of RCTs published in obesity journals is suboptimal, despite current guidelines and policies. To complement existing standards, editorial boards should incorporate mandatory fields within the online manuscript submission process to enhance the quality, transparency, and comprehensiveness of reporting RCTs in obesity journals.

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

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

Reporting of adverse events and statistical details of efficacy estimates in randomized clinical trials of pain in temporomandibular disorders: Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks systematic review

BACKGROUND

Statistical methods and adverse events (that is, harms) data affect the accuracy of conclusions about the risk-to-benefit ratio of treatments for temporomandibular disorders (TMDs). The authors reviewed the quality of reporting in TMD clinical trials to highlight practices that are in need of improvement.

TYPES OF STUDIES REVIEWED

The authors included articles published between 1969 and May 31, 2013, in which the investigators reported randomized clinical trials of TMD treatments with pain as a principal outcome variable. Investigators in trials of nonpharmacologic and noninvasive treatments were required to at least mask the participants and assessors; all others were required to be double masked.

RESULTS

Ninety articles qualified for this review: 39 published between 1971 and 2005 (older articles) and 51 published between 2006 and 2013 (newer articles). Specification of primary outcome analyses, methods to accommodate missing data, and adverse event collection methods and rates were generally poor. In some cases, there was apparent improvement from the older to the newer cohort; however, reporting of these methodological details remained inadequate even in the newer articles.

PRACTICAL IMPLICATIONS

This review is designed to alert authors, reviewers, editors, and readers of TMD clinical trials to these issues and improve reporting quality in the future.

Prevention of selective outcome reporting: let us start from the beginning

BACKGROUND

Healthcare professionals and patients could be negatively influenced in their judgments by articles and meta-analyses presenting selective outcome reporting. Clinical trials should be transparent from inception to the publication of results. To this end, trial prospective registration is an ethical and scientific requirement that have shown to be effective in preventing selective reporting of outcomes. However, even journals with a clear pre-registration policy publish trial results that were retrospectively registered.

SITUATION

Analyses of registration of randomized clinical trials recently published in top specialty journals and of meta-analyses with suspicion of including trials with outcome reporting bias have shown that retrospective registration is in the range from 56 to 76 %. This translates into publication of primary endpoints that differ from those included in the registry: some 30 % of trials showed discrepancies between the primary endpoint in the trial registry and the article. Furthermore, it has been shown that 8 % of all clinical trials published by 6 high-impact ICMJE-member journals was retrospectively registered after primary endpoint ascertainment could have had taken place, raising concerns that endpoints may not have been pre-specified, or were changed. With regards to meta-analyses, 34 % of Cochrane systematic reviews included one or more trials with a high suspicion of selective reporting bias for the primary outcome.

PROPOSAL

Retrospective registration of trials may foster selective outcome reporting unless journal editors implement specific quality control processes aiming to prevent or minimize this type of bias. Prospective registration of trials-and protocol public disclosure if proven effective in future studies-prevents outcome reporting bias, a must to ensure clinicians and patients have access to reliable clinical trial results. Journal editors should enforce, rather than encourage, appropriate measures to ensure publication of trials free of outcome reporting bias.

Design and Validity of Randomized Controlled Dental Restorative Trials

Background: The evidence stemming from trials on restorative materials is shaped not only by trial findings, but also trial design and validity. We aimed to evaluate both aspects in randomized controlled dental restorative trials published from 2005-2015. Methods: Using systematic review methodology, we retrieved trials comparing restorative or adhesive dental materials. Two authors independently assessed design, risk of bias, registration status, and findings of trials. Descriptive and regression analyses were performed. Results: 114 studies on 15,321 restorations placed mainly in permanent teeth of 5232 patients were included. Per trial, the median number of patients was 37 (25th/75th percentiles: 30/51). Follow-up was 24 (20/48) months. Seventeen percent of trials reported on sample size calculations, 2% had been registered. Most trials (90%) used US Public Health Service (USPHS) criteria, and had a high risk of bias. More recent trials were more likely to have been registered, to have reported on sample size calculations, to be of low risk of bias, and to use other than USPHS-criteria. Twenty-three percent of trials yielded significant differences between groups. The likelihood of such differences was significantly increased in older studies, studies with potential reporting bias, published in journals with high impact factor (>2), longer follow-up periods, and not using USPHS-criteria. Conclusions: The majority of dental restorative trials published from 2005-2015 had limited validity. Risk of bias decreased in more recent trials. Future trials should aim for high validity, be registered, and use defined and appropriate sample sizes, follow-up periods, and outcome measures.

From protocol to published report: a study of consistency in the reporting of academic drug trials

BACKGROUND

Unacknowledged inconsistencies in the reporting of clinical trials undermine the validity of the results of the trials. Little is known about inconsistency in the reporting of academic clinical drug trials. Therefore, we investigated the prevalence of consistency between protocols and published reports of academic clinical drug trials.

METHODS

A comparison was made between study protocols and their corresponding published reports. We assessed the overall consistency, which was defined as the absence of discrepancy regarding study type (categorized as either exploratory or confirmatory), primary objective, primary endpoint, and--for confirmatory trials only--hypothesis and sample size calculation. We used logistic regression, χ(2), and Fisher's exact test.

RESULTS

A total of 282 applications of academic clinical drug trials were submitted to the Danish Health and Medicines Authority in 1999, 2001, and 2003, 95 of which fulfilled the eligibility criteria and had at least one corresponding published report reporting data on trial subjects. Overall consistency was observed in 39% of the trials (95% CI: 29 to 49%). Randomized controlled trials (RCTs) constituted 72% (95% CI: 63 to 81%) of the sample, and 87% (95% CI: 80 to 94%) of the trials were hospital based.

CONCLUSIONS

Overall consistency between protocols and their corresponding published reports was low. Motivators for the inconsistencies are unknown but do not seem restricted to economic incentives.

Comparison of registered and published outcomes in randomized controlled trials: a systematic review

BACKGROUND

Clinical trial registries can improve the validity of trial results by facilitating comparisons between prospectively planned and reported outcomes. Previous reports on the frequency of planned and reported outcome inconsistencies have reported widely discrepant results. It is unknown whether these discrepancies are due to differences between the included trials, or to methodological differences between studies. We aimed to systematically review the prevalence and nature of discrepancies between registered and published outcomes among clinical trials.

METHODS

We searched MEDLINE via PubMed, EMBASE, and CINAHL, and checked references of included publications to identify studies that compared trial outcomes as documented in a publicly accessible clinical trials registry with published trial outcomes. Two authors independently selected eligible studies and performed data extraction. We present summary data rather than pooled analyses owing to methodological heterogeneity among the included studies.

RESULTS

Twenty-seven studies were eligible for inclusion. The overall risk of bias among included studies was moderate to high. These studies assessed outcome agreement for a median of 65 individual trials (interquartile range [IQR] 25-110). The median proportion of trials with an identified discrepancy between the registered and published primary outcome was 31%; substantial variability in the prevalence of these primary outcome discrepancies was observed among the included studies (range 0% (0/66) to 100% (1/1), IQR 17-45%). We found less variability within the subset of studies that assessed the agreement between prospectively registered outcomes and published outcomes, among which the median observed discrepancy rate was 41% (range 30% (13/43) to 100% (1/1), IQR 33-48%). The nature of observed primary outcome discrepancies also varied substantially between included studies. Among the studies providing detailed descriptions of these outcome discrepancies, a median of 13 % of trials introduced a new, unregistered outcome in the published manuscript (IQR 5-16%).

CONCLUSIONS

Discrepancies between registered and published outcomes of clinical trials are common regardless of funding mechanism or the journals in which they are published. Consistent reporting of prospectively defined outcomes and consistent utilization of registry data during the peer review process may improve the validity of clinical trial publications.