Trial registration, publication rate and characteristics in the research field of otology: A cross-sectional study.
ABSTRACT: OBJECTIVES:To examine 1) the publication rate of registered otology trials in ClinicalTrials.gov, 2) the public availability of the results, 3) the study characteristics associated with publication, and 4) the time to publication after trial completion. BACKGROUND:Publication bias, the publication or non-publication of research findings, depending on the nature and direction of results, is accountable for wrong treatment decisions. The extent of publication bias in otology trials has not been evaluated. METHODS:All registered otology trials were extracted from ClinicalTrials.gov with completion date up to December 2015. A search strategy was used to identify corresponding publications up to June 2017, providing at least 18 months to publish the results after trial completion. Characteristics were obtained from ClinicalTrials.gov and corresponding publications. Regression models were used to examine study characteristics associated with publication or non-publication. RESULTS:From the 419 trials identified on ClinicalTrials.gov, 225 (53.7%) corresponding publications were found in PubMed. Among these, 109 (48.4%) publications were cited on ClinicalTrials.gov and 124 (55.1%) articles reported the National Clinical Trial registry number. For 36 (8.6%) trials, results were only reported in ClinicalTrials.gov. Trials with a biological intervention were more likely to be published than studies involving drugs (odds ratio (OR) 10.41, 95% confidence interval (CI) 1.26-86.22, P = 0.030). Trials funded by industry were less likely to be published (OR 0.46, CI 0.25-0.84, P = 0.011). The median trial duration was 20 months (interquartile range (IQR) 26 months), and median time from trial completion to publication was 24 months (IQR 22 months). CONCLUSION:In 37.7% of the registered otology trials the results remained unpublished, even several years after trial completion. With little citations on ClinicalTrials.gov and low reporting of the Clinical Trial registry number, the accessibility is limited. Our findings show that there is room for improvement in accuracy of trial registration and publication of results, in order to diminish publication bias in otology studies.
Project description:Pediatric liver transplantation is a highly specialized, challenging field. Selective reporting may introduce bias into evidence based clinical decision making, but the precise extent of unpublished data in pediatric liver transplantation is unknown today. We therefore assessed the public availability of completed clinical trials in pediatric liver transplantation.We determined the proportion of published and unpublished pre-registered, completed pediatric liver transplantation studies on ClinicalTrials.gov. The major trial and literature databases, i.e., clinicaltrials.gov, Pubmed, and Google Scholar were searched for publications. In addition, principal investigators or sponsors were contacted directly. STROBE criteria were applied for the descriptive analysis.Out of N = 33 studies focusing on pediatric liver transplantation registered as completed until March 2014 on clinicaltrials.gov, N = 19 (58%) studies were published until February 2015, whereas N = 14 (42%) studies remained unpublished. The unpublished trials contain data from N = 2105 (35%) patients out of a total population of N = 6044 study participants. Median time-to-publication, i.e., the period from completion of the trial until public availability of the data was 23 IQR 10 to 28 months. Most pertinent key questions in pediatric liver transplantation, i.e., surgical procedures, immunosuppression, concomitant infections, and graft rejection were addressed in 48% of studies (N = 16/33), half of which were published.Half of the clinical trials in pediatric liver transplantation focused on key questions such as surgical procedures, immunosuppression, concomitant infections, and graft rejection. There is still a considerable amount of unpublished studies results in pediatric liver transplantation. Time from study completion to publication was almost twice as long as the 12 months mandatory FDAAA-timeline with a trend towards acceleration over time. The data should serve as a baseline for future progress in the field. More stringent publication of completed trials and focused multicenter research should be encouraged.
Project description:OBJECTIVES:Emergence delirium (ED) is a frequent and potentially serious complication of general anaesthesia in children. Although there are various treatment strategies, no general management recommendations can be made. Selective reporting of study results may impair clinical decision-making. We, therefore, analysed whether the results of completed registered clinical studies in patients with paediatric ED are publicly available or remain unpublished. DESIGN:Cross-sectional analysis. SETTING:ClinicalTrials.gov and ClinicalTrialsRegister.eu. PARTICIPANTS AND OUTCOME MEASURES:We determined the proportion of published and unpublished studies registered at ClinicalTrials.gov and ClinicalTrialsRegister.eu that were marked as completed by 1st September 2018. The major trial and literature databases were used to search for publications. In addition, the study investigators were contacted directly. For published trials, time to publication was calculated as the difference in months between study completion date and publication date. RESULTS:Of the 44 registered studies on paediatric ED, only 24 (54%) were published by September 2019. Published trials contained data from n=2556 patients, whereas n=1644 patients were enrolled in unpublished trials. Median time to publication was 19 months. Studies completed in recent years were published faster, but still only 9 of 24 trials were published within 12 months of completion. CONCLUSION:There is a distinct publication gap in clinical research in paediatric ED that may have an impact on meta-analyses and clinical practice.
Project description: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.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.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.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.
Project description:BACKGROUND:Clinical trials are key to advancing evidence-based medical research. The medical research literature has identified the impact of publication bias in clinical trials. Selective publication for positive outcomes or nonpublication of negative results could misdirect subsequent research and result in literature reviews leaning toward positive outcomes. Digital health trials face specific challenges, including a high attrition rate, usability issues, and insufficient formative research. These challenges may contribute to nonpublication of the trial results. To our knowledge, no study has thus far reported the nonpublication rates of digital health trials. OBJECTIVE:The primary research objective was to evaluate the nonpublication rate of digital health randomized clinical trials registered in ClinicalTrials.gov. Our secondary research objective was to determine whether industry funding contributes to nonpublication of digital health trials. METHODS:To identify digital health trials, a list of 47 search terms was developed through an iterative process and applied to the "Title," "Interventions," and "Outcome Measures" fields of registered trials with completion dates between April 1, 2010, and April 1, 2013. The search was based on the full dataset exported from the ClinlicalTrials.gov database, with 265,657 trials entries downloaded on February 10, 2018, to allow publication of studies within 5 years of trial completion. We identified publications related to the results of the trials through a comprehensive approach that included an automated and manual publication-identification process. RESULTS:In total, 6717 articles matched the a priori search terms, of which 803 trials matched our latest completion date criteria. After screening, 556 trials were included in this study. We found that 150 (27%) of all included trials remained unpublished 5 years after their completion date. In bivariate analyses, we observed statistically significant differences in trial characteristics between published and unpublished trials in terms of the intervention target condition, country, trial size, trial phases, recruitment, and prospective trial registration. In multivariate analyses, differences in trial characteristics between published and unpublished trials remained statistically significant for the intervention target condition, country, trial size, trial phases, and recruitment; the odds of publication for non-US-based trials were significant, and these trials were 3.3 (95% CI 1.845-5.964) times more likely to be published than US-based trials. We observed a trend of 1.5 times higher nonpublication rates for industry-funded trials. However, the trend was not statistically significant. CONCLUSIONS:In the domain of digital health, 27% of registered clinical trials results are unpublished, which is lower than nonpublication rates in other fields. There are substantial differences in nonpublication rates between trials funded by industry and nonindustry sponsors. Further research is required to define the determinants and reasons for nonpublication and, more importantly, to articulate the impact and risk of publication bias in the field of digital health trials.
Project description:Although selective reporting of clinical trial results introduces bias into evidence based clinical decision making, publication bias in pediatric epilepsy is unknown today. Since there is a considerable ambiguity in the treatment of an important and common clinical problem, pediatric seizures, we assessed the public availability of results of phase 3 clinical trials that evaluated treatments of seizures in children and adolescents as a surrogate for the extent of publication bias in pediatric epilepsy.We determined the proportion of published and unpublished study results of phase 3 clinical trials that were registered as completed on ClinicalTrials.gov. We searched ClinicalTrials.gov, PubMed, and Google Scholar for publications and contacted principal investigators or sponsors. The analysis was performed according to STROBE criteria.Considering studies that were completed before 2014 (N = 99), 75 (76%) pediatric phase 3 clinical trials were published but 24 (24%) remained unpublished. The unpublished studies concealed evidence from 4,437 patients. Mean time-to-publication was 25 SD ± 15.6 months, more than twice as long as mandated.Ten years after the ICMJE's clinical trials registration initiative there is still a considerable amount of selective reporting and delay of publication that potentially distorts the body of evidence in the treatment of pediatric seizures.
Project description:To measure the rate of non-publication and assess possible publication bias in clinical trials of electronic health records.We searched ClinicalTrials.gov to identify registered clinical trials of electronic health records and searched the biomedical literature and contacted trial investigators to determine whether the results of the trials were published. Publications were judged as positive, negative, or neutral according to the primary outcome.Seventy-six percent of trials had publications describing trial results; of these, 74% were positive, 21% were neutral, and 4% were negative (harmful). Of unpublished studies for which the investigator responded, 43% were positive, 57% were neutral, and none were negative; the lower rate of positive results was significant (p<0.001).The rate of non-publication in electronic health record studies is similar to that in other biomedical studies. There appears to be a bias toward publication of positive trials in this domain.
Project description:To limit selective and incomplete publication of the results of clinical trials, registries including ClinicalTrials.gov were introduced. The ClinicalTrials.gov registry added a results database in 2008 to enable researchers to post the results of their trials as stipulated by the Food and Drug Administration Amendment Act of 2007. This study aimed to determine the direction and magnitude of any change in publication proportions of registered breast cancer trials that occurred since the inception of the ClinicalTrials.gov results database.A cross-sectional study design was employed using ClinicalTrials.gov, a publicly available registry/results database as the primary data source. Registry contents under the subcategories 'Breast Neoplasms' and 'Breast Neoplasms, Male' were downloaded on 1 August 2015. A literature search for included trials was afterwards conducted using MEDLINE and DISCOVER databases to determine publication status of the registered breast cancer trials.Nearly half (168/340) of the listed trials had been published, with a median time to publication of 24 months (Q1?=?14 months, Q3?=?42 months). Only 86 trials were published within 24 months of completion. There was no significant increase in publication proportions of trials that were completed before the introduction of the results database compared to those completed after (OR?=?1.00, 95 % CI?=?.61 to 1.63; adjusted OR?=?0.84, 95 % CI?=?.51 to 1.39). Characteristics associated with publication included trial type (observational versus interventional adjusted OR?=?.28, 95 % CI?=?.10 to .74) and completion/termination status (terminated versus completed adjusted OR?=?.22, 95 % CI?=?.09 to .51).Less than a half of breast cancer trials registered in ClinicalTrials.gov are published in peer-reviewed journals.
Project description:OBJECTIVE:To determine rates of publication and reporting of results within two years for all completed clinical trials registered in ClinicalTrials.gov across leading academic medical centers in the United States. DESIGN:Cross sectional analysis. SETTING:Academic medical centers in the United States. PARTICIPANTS:Academic medical centers with 40 or more completed interventional trials registered on ClinicalTrials.gov. METHODS:Using the Aggregate Analysis of ClinicalTrials.gov database and manual review, we identified all interventional clinical trials registered on ClinicalTrials.gov with a primary completion date between October 2007 and September 2010 and with a lead investigator affiliated with an academic medical center. MAIN OUTCOME MEASURES:The proportion of trials that disseminated results, defined as publication or reporting of results on ClinicalTrials.gov, overall and within 24 months of study completion. RESULTS:We identified 4347 interventional clinical trials across 51 academic medical centers. Among the trials, 1005 (23%) enrolled more than 100 patients, 1216 (28%) were double blind, and 2169 (50%) were phase II through IV. Overall, academic medical centers disseminated results for 2892 (66%) trials, with 1560 (35.9%) achieving this within 24 months of study completion. The proportion of clinical trials with results disseminated within 24 months of study completion ranged from 16.2% (6/37) to 55.3% (57/103) across academic medical centers. The proportion of clinical trials published within 24 months of study completion ranged from 10.8% (4/37) to 40.3% (31/77) across academic medical centers, whereas results reporting on ClinicalTrials.gov ranged from 1.6% (2/122) to 40.7% (72/177). CONCLUSIONS:Despite the ethical mandate and expressed values and mission of academic institutions, there is poor performance and noticeable variation in the dissemination of clinical trial results across leading academic medical centers.
Project description:OBJECTIVE:Appendicitis is considered the most frequent surgical emergency in children. While the management of paediatric appendicitis is evolving, the precise amount of unpublished completed trials, potentially introducing bias into meta-analyses, is unknown. Controversial issues include the appropriate choice of surgical procedures, criteria for diagnosis of appendicitis, the role of antibiotic treatment and pain management. Selective reporting may introduce bias into evidence-based clinical decision-making, and the current, precise extent of unpublished results in paediatric appendicitis is unknown. We therefore assessed the publication status of completed clinical studies involving children registered on ClinicalTrials.gov. DESIGN:Cross sectional analysis. STrengthening the Reporting of OBservational studies in Epidemiology criteria were applied for design and analysis. SETTING AND PARTICIPANTS:ClinicalTrials.gov was queried for completed studies which were matched to publications on ClinicalTrials.gov, PubMed or Google Scholar. If no publication could be identified, principal investigators were contacted. INTERVENTIONS/EXPOSURE:Observational analysis. PRIMARY AND SECONDARY OUTCOME MEASURES:The proportion of published and unpublished studies was calculated. Subgroup analysis included studies on surgical procedures, diagnosis, antibiotic treatment and pain management. RESULTS:Out of n=52 completed clinical studies involving children with appendicitis, n=33 (63%) were published and n=19 (37%) were unpublished. Eighty-three per cent (n=43/52) of clinical trials assessed the above-listed controversial issues. Diagnostic studies were most rigorously published (91% of trials reported), data on surgical procedures, antibiotic and pain management were less transparent. Sixty-six per cent of interventional studies and 60% of randomised studies were published. Median time-to-publication, for example, the delay between completion of the trial until public availability of the results was 24 (IQR 12-36), range 2-92 months. CONCLUSION:Despite the importance of appendicitis in clinical practice for the paediatric surgeon, there remains scientific uncertainty due to unpublished clinical trial results with room for improvement in the future. These data are helpful in framing the shifting paradigms in paediatric appendicitis because it adds transparency to the debate.
Project description:To estimate the frequency with which results of large randomized clinical trials registered with ClinicalTrials.gov are not available to the public.Cross sectional analysisTrials with at least 500 participants that were prospectively registered with ClinicalTrials.gov and completed prior to January 2009.PubMed, Google Scholar, and Embase were searched to identify published manuscripts containing trial results. The final literature search occurred in November 2012. Registry entries for unpublished trials were reviewed to determine whether results for these studies were available in the ClinicalTrials.gov results database.The frequency of non-publication of trial results and, among unpublished studies, the frequency with which results are unavailable in the ClinicalTrials.gov database.Of 585 registered trials, 171 (29%) remained unpublished. These 171 unpublished trials had an estimated total enrollment of 299,763 study participants. The median time between study completion and the final literature search was 60 months for unpublished trials. Non-publication was more common among trials that received industry funding (150/468, 32%) than those that did not (21/117, 18%), P=0.003. Of the 171 unpublished trials, 133 (78%) had no results available in ClinicalTrials.gov.Among this group of large clinical trials, non-publication of results was common and the availability of results in the ClinicalTrials.gov database was limited. A substantial number of study participants were exposed to the risks of trial participation without the societal benefits that accompany the dissemination of trial results.