ObjectiveTo investigate the domestic and abroad hypertension-related clinical trial registration and to analyze the registration of hypertension-related clinical researches in China.MethodsUsing hypertension as the keyword, we searched ClinicalTrials.gov and Chinese Clinical Trial Registry (ChiCTR) from January 2008 to December 2018. We analyzed the collected data on the distribution of registered clinical researches, annual trends, sample sizes, trial progress, research types, study designs, blind methods, clinical stages, the number of participating institutions, the leading institutions, etc.ResultsThe total number of registered hypertension-related clinical trails was 4 991 all over the world, and 551 items were conducted in China. Most of the sample sizes of Chinese hypertension-related clinical trials were 100 to 999. The main types of trials were interventional studies (393 items, 71.32%), followed by observational studies (126 items, 22.87%). Randomized parallel control studies (300 items, 76.34%) were the key component of interventional studies, while cohort studies (61 items, 48.41%) were the chief component of observational studies. The main stages of clinical trials were stage Ⅲ (80 items) and stage Ⅳ (122 items). There were 369 domestic single-center clinical trials (66.97%), 89 domestic multi-center clinical trials (16.15%), and 93 international multi-center clinical trials (16.88%). Among the 93 international multi-center trials of hypertension, only 25 were led by China.ConclusionsThe number of Chinese hypertension-related clinical trial registrations increased year by year and then decreased slightly, but the amount of registrations is limited. The quantity and scale of multicenter clinical studies were not as good as America. China should strengthen the awareness of clinical research registration, strengthen the publicity and supervision of the registration of clinical researches by the department of science and management, improve the number of clinical trial registrations, make Chinese clinical researches more transparent, and strive to lead more international multi-center clinical trials.
ObjectiveTo compare drug clinical trials between China, the United States, Europe and Japan in terms of study type, design, completion and results publication.MethodsWe randomly selected 190 clinical trials that were registered in ClinicalTrials.gov from 2009 to 2014, and followed up to December 31st, 2019. Comparisons were made for the type of sponsor, phase, design, and completion status by the sponsor’s country.ResultsAmong all included clinical trials, trials from the United States, Europe, Japan and China accounted for 50.5%, 34.2%, 9.0% and 6.3%, respectively. Among these trials, 71.1% had been completed and 69.5% disclosed results had been published publicly prior to the end of follow-up, and differences between countries were statistically significant (P<0.05). Two-thirds of the trials in China were phase Ⅲ/Ⅳ trials; in contrast, most of the clinical trials in the United States and Europe were phase Ⅰ/Ⅱ trials. The proportion of using double-blind, randomized controlled trial design was the highest in the United States (46.9%) and the lowest in China (8.3%). Chinese sponsors were mostly hospitals/universities (58.3%), while in other countries drug trials were mostly sponsored by the industry and in Japan the proportion was as high as 94.0%.ConclusionsThe number of drug trials registered in ClinicalTrials.gov from China is small and these trials are less likely to be completed and have results published/disclosed. Pharmaceutical companies in China should pay more attention to the public registration of their clinical trials, particularly those in early phases, and improve trial design and management.
ObjectiveTo explore the application of enhanced funnel plots (EFP) and trial sequential analysis (TSA) in robustness assessment of meta-analysis results.MethodsData were extracted from published meta-analysis. The EFP was used to evaluate the robustness of the significance and heterogeneity of the current meta-analysis. The TSA was used to judge the sufficiency of the cumulative sample size of the current meta-analysis and to assess the robustness of conclusions based on current evidence.ResultsThe EFP showed that the meta-analysis results of low-density lipoprotein (LDL) was robust, and the meta-analysis results of triglyceride (TG), total cholesterol (TC) and high-density lipoprotein (HDL) were not stable. The TSA showed that the cumulative sample size of LDL had reached the required information size (RIS), and the current conclusion was stable. The cumulative Z value of TG, TC and HDL neither reached the RIS nor passed through the TSA monitoring boundary or futility boundary, indicating that current conclusions were not robust.ConclusionsThe combination of EFP and TSA can make a comprehensive judgment on the robustness of current meta-analysis results, and provide methodological support in the robustness assessment of results for future systematic reviews and meta-analyses.
The assumption of fixed-effects model is based on that the true effect of the each trial is same. However, the assumption of random-effects model is based on that the true effect of included trials is normal distributed. The total variance is equal to the sum of within-trial variance and between-trial variance under the random-effects model. There are many estimators of the between-trial variance. The aim of this paper is to give a brief introduction of the estimators of between-trial variance in trial sequential analysis for random-effects model.
ObjectivesTo analyze the research status and hot spots of hypertension-related clinical trials in special Chinese population registered on the Chinese Clinical Trial Registry (ChiCTR), so as to provide a basis for the development of hypertension-related research in special population in China.MethodsThe ChiCTR was searched online (up to August 31st, 2019, no limitation in the status of trial registration), all clinical trials on hypertension in special population were collected, and the general characteristics, researched diseases, research types, intervention measures and main outcomes of the trials were analyzed.ResultsA total of 64 hypertension-related clinical trials in special population registered in the ChiCTR were included, including 41 (64.1%) trials registered in last 3 years. The registration status of 46 (71.9%) trials was pre-registration. The registered authors were mainly from colleges and universities or medical institutions (n = 61, 95.3%), of which 60.9% were registered in Beijing, Shanghai, Guangdong, Zhejiang, Jiangsu and Hebei. The researched diseases mainly included elderly hypertension and hypertensive stroke, accounting for 50% of the total. Additionally, 37 (57.8%) clinical trials were intervention studies, of which 21 (56.7%) were drug-based intervention studies. Blood pressure, blood glucose, cardiovascular and cerebrovascular events, blood lipid, cranial MRI and Glasgow Coma Scale were the commonly used outcomes, accounting for 58.5% of the total outcomes. Most blood pressure measurements did not indicate the measurement method (n = 22, 64.7%).ConclusionsThe quantity of hypertension-related clinical trials in special population registered on the ChiCTR is increasing, however, there exists regional imbalance. The drug intervention-related clinical trials of elderly hypertension have become a research hot spot. However, blood pressure measurement method is not indicated in most trials, and some researchers do not register in time. Therefore, it is suggested that researchers should further strengthen the awareness of carrying out high-quality clinical trials.
The quality of reporting of randomized clinical trials could be significantly improved by the application of CONSORT （Consolidated Standards of Reporting Trials） statement. We compared and analyzed the difference of acceptance of CONSORT statement between Chinese medical journals and Western medical journals, and proposed to disseminate and apply CONSORT statement to improve the quality of reporting of randomized clinical trials and medical journals.
Trial sequential analysis (TSA) could be performed in both TSA software and Stata software. The implementation process of TSA in Stata needs the command of "metacumbounds" of Stata combines with the packages of "foreign" and "ldbounds" of R software. This paper briefly introduces how to implement TSA using Stata software.
Cumulative meta-analysis could help researchers to justify the effectiveness of the intervention and whether the obtained evidence is sufficient. However, the process of the meta-analysis does not adjust the repeated testing of the null hypothesis and neither quantifies the statistical power. The sequential meta-analysis has solved the aforementioned problems and has been widely used in the clinical practice and decision-making. Currently several methods of sequential meta-analysis have been proposed and these methods differ from each other. Of which, the methodology of trial sequential (TSA) is well developed and corresponding performance is relatively easy; the methodology of double-triangular test of Whitehead is lagged than TSA and its performance is relatively difficult; the approach of semi-Bayes refers to the theory of Bayes and it's very difficult to generalize. Our paper aimed to give a brief introduction of the methodology of the sequential meta-analysis.
Objective To detect the false-negative results of cumulative meta-analyses of Cochrane Urology Group with the trial sequential analysis (TSA). Methods The Urology Group of The Cochrane Library (Issue 6, 2016) was searched to collect meta-analyses with negative results. Two researchers independently screened literature and extracted data of included meta-analyses. Then, TSA was performed using TSA software version 0.9 beta. Results A total of 11 papers involving 12 meta-analyses were included. The results of TSA showed that, four (33%) out of 12 meta-analyses were potentially false-negative results for failing to surpass the trial sequential monitoring boundary and to reach the required information size. Conclusion Some of the negative results of systematic reviews from Cochrane Urology Group was false-negative. TSA can help researchers to identify the false-negative results of meta-analyses.
Objective To evaluate the quality of the registration information for trials sponsored by China registered in the WHO International Clinical Trial Registration Platform (ICTRP) primary registries or other registries that meet the requirements of the International Committee Medical Journal Editor (ICMJE). Methods We assessed the registration information for trials registered in the 9 WHO primary registries and one other registry that met the requirements of ICJME as of 15 October 2008. We analyzed the trial registration data set in each registry and assessed the registration quality against the WHO Trial Registration Data Set (TRDS). We also evaluated the quality of the information in the Source(s) of Monetary or Material Support section, using a specially prepared scale. Results The entries in four registries met the 20 items of the WHO TRDS. These were the Chinese Clinical Trial Registration Center (ChiCR), Australian New Zealand Clinical Trials Registry (NZCTR), Clinical Trials Registry – India (CTRI), and Sri Lanka Clinical Trials Registry (SLCTR). Registration quality varied among the different registries. For example, using the Scale of TRDS, the NZCTR scoreda median of 19 points, ChiCTR (median = 18 points), ISRCTN.org (median = 17 points), and Clinical trials.org (median = 12 points). The data on monetary or material support for ChiCTR and ISRCTN.org were relatively complete and the score on our Scale for the Completeness of Funding Registration Quality ranged from ChiCTR (median = 7 points), ISRCTN.org (median = 6 points), NZCTR (median = 3 points) to clinicaltrials.gov (median = 2 points). Conclusion Further improvements are needed in both the quantity and quality of trial registration. This could be achieved by full completion of the 20 items of the WHO TRDS. Future research should assess ways to ensure the quality and scope of research registration and the role of mandatory registration of funded research.