ABSTRACT
OBJECTIVES: The aim of our current study was to analyze whether the use of important measures of methodological quality and reporting of randomized clinical trials published in the field of cardiovascular disease research haschanged over time. A furtheraim was to investigate whether there was an improvement over time in the ability of these trials to provide a good estimate of the true intervention effect. METHODS: We conducted two searches in the Cochrane Central Register of Controlled Trials (CENTAL) database to identify randomized cardiovascular clinical trials published in either 2012 or 2017. Randomized clinical trials (RCTs) trials in cardiovascular disease research with adult participants were eligible to be included. We randomly selected 250 RCTs for publication years 2012 and 2017. Trial characteristics, data on measures of methodological quality, and reporting were extracted and the risk of bias for each trial was assessed. RESULTS: As compared to 2012, in 2017 there were significant improvements in the reporting of the presence of a data monitoring committee (42.0% in 2017 compared to 34.4% in 2012; p < 0.001), and a positive change in registering randomized cardiovascular disease research in clinical trial registries (78.4% in 2017 compared to 68.9% in 2012; p = 0.03). We also observed that significantly more RCTs reported sample size calculation (60.4% in 2017 compared to 49.6% in 2012; p < 0.01) in 2017 as compared to 2012. RCTs in 2017 were more likely to have a low overall risk of bias (RoB) than in 2012 (29.2% in 2017 compared to 21.2% in 2012; p < 0.01). However, fewer 2017 RCTs were rated low (50.8% compared to 65.6%; p < 0.001) risk for blinding of participants and personnel, for blinding of outcome assessors (82.4% compared to 90.8%; p < 0.001), and selective outcome reporting (62.8% compared to 80.0%; <0.001). CONCLUSIONS: As compared to 2012, in 2017 there were significant improvements in some, but not all, the important measures of methodological quality. Although more trials in the field of cardiovascular disease research had a lower overall RoB in 2017, the improvement over time was not consistently perceived in all RoB domains.
ABSTRACT
Background: All randomized-controlled trials (RCTs) are required to follow high methodological standards. In this study, we aimed to assess the methodological quality of published cardiovascular clinical research trials in a representative sample of RCTs published in 2017. Methods: Cochrane Central Register of Controlled Trials was used to identify cardiovascular clinical research trials with adult participants published in 2017. Overall, 250 (10%) RCTs were randomly selected from a total of 2,419 studies. Data on general trial characteristics were extracted and the risk of bias (RoB) was determined. Results: Overall, 86% of RCTs have reported at least one statistically significant result, with the primary outcome significant in 69%, treatment favored in 55%, and adverse events reported in 68%. Less than one-third (29%) of trials were overall low RoB, while the other two-thirds were rated unclear (40%) or with high RoB (31%). Sequence generation, allocation concealment, and selective reporting were the domains most often rated with high RoB. Drug trials were more likely to have low RoB than non-drug trials. Significant differences were found in RoB for the allocation concealment and blinding of participants and personnel between industry-funded and non-industry-funded trials, with industry-funded trials more often rated at low RoB. Conclusion: Almost two-thirds of RCTs in the field of cardiovascular disease (CVD) research, were at high or unclear RoB, indicating a need for more rigorous trial planning and conduct. Prospective trial registration is a factor predicting a lower risk of bias.
ABSTRACT
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.
