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.
In 2007, the findings from clinical trials on stroke treatment have been both encouraging and disappointing. In order to interpret the challenges and opportunity in evidence-based stroke practice, we reviewed several major clinical trials in stroke that were published last year. It revealed that we should strengthen the evidence base for acute stroke care by conducting more high-quality randomized controlled trials and by increasing the energy, resources and manpower available for these trials.
The robustness of results of statistical analysis would be altered on the condition of repeated update of traditional meta-analysis and cumulative meta-analysis. In addition, the cumulative meta-analysis lacks estimation of the sample size. While trail sequential analysis (TSA), which introduces group sequential analysis in meta-analysis, can adjust the random error and ultimately estimate the required sample size of the systematic review or meta-analysis. TSA is performed in TSA software. In the present study, we aimed to introduce how to use the TSA software for performing meta-analysis.
Objective To detect the false-positive results of cumulative meta-analyses of Cochrane Urology Group with the trial sequential analysis (TSA). Methods The systematic reviews of Urology Group of The Cochrane Library were searched to collect meta-analyses with positive 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 meta-analyses were included. The results of TSA showed that, 8 of 11 (72.7%) meta-analyses were potentially false-positive results for failing to surpass the trial sequential monitoring boundary and to reach the required information size. Conclusion TSA can help researchers to identify the false-positive 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.
ObjectiveTo systematically review the association between angiotension-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and osteoarthritis (OA) by using meta-analysis and trial sequential analysis (TSA). MethodsThe PubMed, EMbase, CNKI, CBM, VIP, and WanFang Data were searched up to October 12th, 2016 for case-control or cohort studies on the correlation between ACE I/D polymorphism and OA risk. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis and TSA analysis were performed using Stata 13.1 software and TSA v0.9 soft ware. ResultsA total of six case-control studies involving 1 165 OA patients and 1 029 controls were included. The results of meta-analysis showed that the ACE I/D was associated with OA risk (DD+DI vs. II: OR=1.72, 95%CI 1.02 to 2.90, P=0.04; DI vs. II: OR=1.65, 95%CI 1.06 to 2.56, P=0.03). Subgroup analysis of ethnicity showed that, in Caucasians, the ACE I/D was associated with OA risk (DD vs. DI+II: OR=2.10, 95%CI 1.54 to 2.85, P<0.01; DD+DI vs. II: OR=3.11, 95%CI 2.20 to 4.39, P<0.01; DD vs. II: OR=4.01, 95%CI 2.68 to 6.00, P<0.01; DI vs. II: OR=2.65, 95%CI 1.06 to 2.56, P<0.01; D vs. I: OR=2.11, 95%CI 1.72 to 2.58, P=0.73). And TSA showed that all of the cumulative Z-curve strode the conventional and TSA threshold value which suggested the result of the association between ACE I/D polymorphism and OA in Caucasians was very reliable. However, the association did not exist in Asians (DD vs. DI+II: OR=0.80, 95%CI 0.60 to 1.07, P=0.13; DD+DI vs. II: OR=1.08, 95%CI 0.87 to 1.35, P=0.49; DD vs. II: OR=0.86, 95%CI 0.62 to 1.20, P=0.38; DI vs. II: OR=1.18, 95%CI 0.93 to 1.50, P=0.19; D vs. I: OR=0.93, 95%CI 0.83 to 1.14, P=0.73). And the results of TSA displayed that all of the cumulative Z-curve did not strode both TSA threshold value and required information size line excepting for DD vs. DI+II genetic model which suggested that the sample-size in Asians was insufficient. ConclusionsThe ACE D allele maybe a risk factor for OA in Caucasians. However, the association between ACE I/D polymorphism and OA risk in Asians still need more studies to prove.
ObjectivesTo analyze the metrological characteristics of hypertension-related clinical trials registered on Chinese Clinical Trial Registry (ChiCTR), and discuss the characteristics and developmental trends of hypertension clinical trials registration in China.MethodsChiCTR were searched to collect hypertension-related clinical trials from inception to March 25th, 2018. The characteristics of registered trials were analyzed.ResultsA total of 135 registered trials were included, in which the trials from Beijing, Guangdong, Jiangsu, Chongqing and Shanghai accounted for 55.5%. 115 trials were pre-registered. The top three funding sources were from finance (32, 23.7%), self-financing (25, 18.5%) and hospital (20, 14.8%), respectively. Of all 79 randomized controlled trials, 55 were blank/missing in the entry of blinding method.ConclusionsThe number of hypertension-related clinical trials in ChiCTR tends to increase, however there are large regional disparities and incomplete, non-standardiazed information in the registration of clinical trials. The relevant departments should increase the publicity on the registration of clinical trials, raise the awareness of registration, and promote the development and registration of high quality clinical trials.
Objective To analyze the current research status, characteristics and development trends of traditional medicine-related clinical trials registration, and to provide ideas and directions for further development of traditional medicine clinical trials. Methods The International Traditional Medicine Clinical Trial Registry (ITMCTR) database was searched by computer from inception to June 30, 2024, with unlimited trial registration status, to collect all the clinical trials on traditional medicine, and analyze the basic information of the trials, the diseases studied and the interventions. Results A total of 4 349 clinical trials related to traditional medicine were included, with the number of registrations peaking in the second half of 2020, and showing a steady upward trend after 2023. The trial sponsors of the study covered 9 countries and a total of 34 provinces/autonomous regions/municipalities in China, led by Beijing, Shanghai, Guangdong, Sichuan, and Zhejiang provinces, accounting for 69.72% of the total. The financial support for the studies was dominated by local government funds in various provinces and cities, accounting for 29.66%. Disease types studied were mainly circulatory system diseases, musculoskeletal system or connective tissue diseases, and tumor diseases, accounting for 29.91% of the total. A total of 3 751 (86.3%) clinical trials were interventional studies, of which randomized parallel control was predominant, and 213 large-sample studies with a sample size of more than 1 000 cases were included. A total of 20 types of interventions were involved, of which 1 114 (29.86%) clinical trials utilized oral prescription of herbal medicine interventions. Conclusion Clinical trial enrollment in traditional medicine has increased overall, but with significant geographic unevenness. Oral herbal soup/granule intervention studies are the mainstream hotspots. It is recommended to strengthen international cooperation, enrich the types of interventions, refine the trial design, and raise the awareness of researchers about the registration of high-quality traditional medicine clinical trials.
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.
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.
