Suchergebnisse

BACKGROUND: Clinical research should provide reliable evidence to clinicians, health policy makers, and researchers. The reliability of evidence will be assured once study planning, conducting, and reporting of results are transparent. The present research investigates publication rates, time until publication, and characteristics of clinical trials on medicinal products associated with timely publication of results, measures of scientific impact, authorship, and open access publication. METHODS: Clinical trials authorized in Hungary in 2012 were followed until publication and/or June 2020. Corresponding scientific publications were searched via clinical trial registries, PubMed (MEDLINE), and Google. RESULTS: Overall, 330 clinical trials were authorized in 2012 of which 232 trials were completed for more than 1 year in June 2020. The proportion of industry initiation was high (97%). Time to publication was 21 (22) months [median (IQR)]. Time to publication was significantly shorter when trials involved both European and non-European countries (26 vs 69 months [median]; hazard ratio = 0.38, 95% CI 0.22–0.66, p< 0.001), and were registered in both EU CTR and clinicaltrials.gov (27 vs 88 months; hazard ratio = 0.24, 95% CI 0.11–0.54; p< 0.001) based on survival analyses. A significant amount (24.1%) of unpublished clinical trial results were accessible in a trial register. The majority of available publications were published "open access" (70.93%). A minority of identified publications had a Hungarian author (21.5%). CONCLUSIONS: We encourage academic researchers to plan, register and conduct trials on medicinal products. Registries should be considered as an important source of information of clinical trial results. Publications with domestic co-authors contribute to the research output of a country. Measurable domestic scientific impact of trials on medicinal products needs further improvement. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at ...

Background Healthcare decisions are ideally based on clinical trial results, published in study registries, as journal articles or summarized in secondary research articles. In this research project, we investigated the impact of academically and commercially sponsored clinical trials on medical practice by measuring the proportion of trials published and cited by systematic reviews and clinical guidelines. Methods We examined 691 multicenter, randomized controlled trials that started in 2005 or later and were completed by the end of 2016. To determine whether sponsorship/funding and place of conduct influence a trial's impact, we created four sub-cohorts of investigator initiated trials (IITs) and industry sponsored trials (ISTs): 120 IITs and 171 ISTs with German contribution compared to 200 IITs and 200 ISTs without German contribution. We balanced the groups for study phase and place of conduct. German IITs were funded by the German Research Foundation (DFG), the Federal Ministry of Education and Research (BMBF), or by another non-commercial research organization. All other trials were drawn from the German Clinical Trials Register or ClinicalTrials.gov. We investigated, to what extent study characteristics were associated with publication and impact using multivariable logistic regressions. Results For 80% of the 691 trials, results were published as result articles in a medical journal and/or study registry, 52% were cited by a systematic review, and 26% reached impact in a clinical guideline. Drug trials and larger trials were associated with a higher probability to be published and to have an impact than non-drug trials and smaller trials. Results of IITs were more often published as a journal article while results of ISTs were more often published in study registries. International ISTs less often gained impact by inclusion in systematic reviews or guidelines than IITs. Conclusion An encouraging high proportion of the clinical trials were published, and a considerable proportion gained impact on clinical practice. However, there is still room for improvement. For publishing study results, study registries have become an alternative or complement to journal articles, especially for ISTs. IITs funded by governmental bodies in Germany reached an impact that is comparable to international IITs and ISTs.

IMPORTANCE: Clinical trial registries are important for gaining an overview of ongoing research efforts and for deterring and identifying publication bias and selective outcome reporting. The reliability of the information in trial registries is uncertain. OBJECTIVE: To assess the reliability of information across registries for trials with multiple registrations. EVIDENCE REVIEW: For this systematic review, 360 protocols of randomized clinical trials (RCTs) approved by research ethics committees in Switzerland, the UK, Canada, and Germany in 2012 were evaluated. Clinical trial registries were searched from March to September 2019 for corresponding registrations of these RCTs. For RCTS that were recorded in more than 1 clinical trial registry, key trial characteristics that should be identical among all trial registries (ie, sponsor, funding source, primary outcome, target sample size, trial status, date of first patient enrollment, results available, and main publication indexed) were extracted in duplicate. Agreement between the different trial registries for these key characteristics was analyzed descriptively. Data analyses were conducted from May 1 to November 30, 2020. Representatives from clinical trial registries were interviewed to discuss the study findings between February 1 and March 31, 2021. FINDINGS: The analysis included 197 RCTs registered in more than 1 trial registry (151 in 2 registries and 46 in 3 registries), with 188 trials in ClinicalTrials.gov, 185 in the European Union Drug Regulating Authorities Clinical Trials Database (EudraCT), 20 in ISRCTN, and 47 in other registries. The agreement of key information across all registries was as follows: 178 of 197 RCTs (90%; 95% CI, 85%-94%) for sponsor, 18 of 20 (90%; 95% CI, 68%-99%) for funding source (funding was not reported on ClinicalTrials.gov), 154 of 197 (78%; 95% CI, 72%-84%) for primary outcome, 90 of 197 (46%; 95% CI, 39%-53%) for trial status, 122 of 194 (63%; 95% CI, 56%-70%) for target sample size, and 43 of 57 (75%; 95% CI, ...