Trial Sequential Analysis (TSA), one kind of cumulative meta-analysis, is a method which introduces sequential analysis into traditional meta-analysis to avoid random errors (false positive or false negative outcomes) that occurred during repeated updates when traditional meta-analysis is performing. It is also applied to calculate required information size (RIS) of a firm conclusion. This study aims to summarize the proposal, fundamental theory, application software, and current limitation of TSA, and to clarify the advantages of TSA on the basis of detailed examples, in order to attract more attention of researchers and promote the methodological development of meta-analysis in China.
Objective To systematically review the differences of selenium levels in environment between endemic and normal regions and in patients with Kaschin-Beck disease and health people. Methods Such databases as PubMed, The Cochrane Library (Issue 8, 2013), EMbase, ISI Web of Knowledge, CNKI, CBM, VIP and WanFang Data were electronically searched to August 16th, 2013 for all observational studies about the differences of selenium levels in environment (including soil, water, and cereal) between endemic and normal regions, and in patients with Kaschin-Beck disease and health people (including blood, urine, and hair) were included. Meta-analysisi was performed using RevMan 5.2 software. Results Forty-six controlled studies were included. The results of meta-analysis showed that, selenium levels in water (SMD= –0.99, 95%CI –1.31 to –0.66), soil (SMD= –1.20, 95%CI –1.92 to –0.49), cereal (SMD= –1.94, 95%CI –2.63 to –1.26) and corn (SMD= –1.66, 95%CI –2.33 to –0.98) in endemic region were lower than those in normal region. The selenium in blood (SMD= –1.03, 95%CI –1.54 to –0.53), blood serum (SMD= –0.66, 95%CI –1.01 to –0.31), red blood cell (SMD= –2.75, 95%CI –4.13 to –1.37), urine (SMD= –0.99, 95%CI –1.43 to –0.55) and hair (SMD= –1.67, 95%CI –2.14 to –1.20) of Kaschin-Beck disease patients were lower than those in healthy people. The results of subgroup analysis also showed that significant differences were found between patients and healthy people in endemic region. The selenium in blood (SMD= –6.12, 95%CI –8.58 to –3.66), blood serum (SMD= –1.02, 95%CI –1.34 to –0.69), red blood cell (SMD= –3.37, 95%CI –5.38 to –1.35), urine (SMD= –1.94, 95%CI –2.54 to –1.34), and hair (SMD –3.49, 95%CI –5.32 to –1.66) of healthy people in endemic region were lower than those in normal region. After removing the specific studies on every pooling outcome with high risk of heterogeneity, the results of sensitivity analysis showed that the results were of robustness and the impact due to heterogenicity was fairly low. Conclusion Selenium levels in external environment in endemic region are significantly lower than those in normal region, and patients’ selenium levels in the body are also significantly lower than the healthy in endemic region. The selenium levels of the healthy in endemic region are also significantly lower than those of the healthy in normal region. Current evidence indicated that lack of selenium in external environment might be related to Kaschin-Beck disease.
Objective To evaluate the psychological trauma incurred by the hospitalization survivor of Zhouqu district after the Zhouqu debris flow so as to provide relevant information for psychological and medical interventions. Methods The psychological state of 67 hospitalized survivors of the disaster and other 47 inpatients with similar complaints but not coming from the disaster area was investigated through a mental health self-assessment questionnaire, self-rating anxiety scale (SAS), self-rating depression scale (SDS) and PTSD-SS scale. Results The post-disaster survivors had different levels of psychological problems and post-traumatic stress disorder, and there were significant differences compared to the control group (Plt;0.01, Plt;0.01). The SDS score and the SAS score of the survivor were 48.44+15.648 and 52.92+11.672, respectively, which were all much higher than those of the control group (Plt;0.01, Plt;0.05). Conclusion The debris flow disaster bring serious psychological trauma to the victims. It is necessary to pertinently carry out post-disaster psychological relief including psychological intervention and regulation for the hospitalized survivors, so as to alleviate and reduce their psychological suffering.
Objective To evaluate the effectiveness and safety of Chinese angelica decoction (CAD) versus conventional treatment (CT) for chronic urticaria (CU). Methods Systematic searches were conducted in PubMed, The Cochrane Library, SCI, EMbase, VIP, CNKI and CBM to collect randomized controlled trials (RCTs) on CAD treating CU from inception to July 2011. Two reviewers independently screened articles according to the inclusion and exclusion criteria, extracted data and evaluated the quality of the included studies. Then meta-analysis was performed using RevMan 5.0.2. Results A total of 11 RCTs involving 1081 patients were included. The results of meta-analysis demonstrated that compared with the CT group (antihistamine therapy), CAD seemed higher in the cure rate (OR=2.36, 95%CI 1.80 to 3.10, I2=22%, Plt;0.000 01), improvement rate (OR=4.56, 95%CI 2.65 to 7.87, I2=0%, Plt;0.000 01), and lower in the relapse rate at the third month after the treatment (OR=0.43, 95%CI 0.22 to 0.82, I2=0%, P=0.01). No study reported the quality of life and severe adverse reactions after CAD treatment. Conclusion Current evidence shows CAD may be superior to CT in treating CU patients. However, due to lack of enough high-quality studies, CAD has to be further studied by conducting more strictly-designed, multicenter, large-scale and double-blind RCTs.
Mendelian randomization (MR) studies use genetic variants as instrumental variables to explore the effects of exposures on health outcomes. STROBE-MR (strengthening the reporting of observational studies in epidemiology using Mendelian randomization) assists authors in reporting their MR studies clearly and transparently, and helpfully to improve the quality of MR. This paper interpreted the STROBE-MR, aiming to help Chinese scholars better understand, disseminate, and apply it.
The PRISMA aims to enhance the transparency and reporting quality of systematic reviews. PRISMA 2020 is an update version of PRISMA 2009, which was published in BMJ in March, 2021. This article compared the PRISMA 2020 and PRISMA 2009, interpreted PRISMA 2020 with representative examples, aiming to help Chinese scholars better understand and apply this reporting guideline, thus to improve the reporting quality of systematic reviews.