New interventions are rapidly progressing into clinical practice through the preclinical study stage. The animal experiments should be comprehensive and critically evaluated for their pivotal role in this process. To integrate the evidence of animal studies by systematic review throws light on intervention outcomes and could decrease risk of participants in human trials. The methodological weakness of animal studies is easy to highlight but robust methods to synthesize evidence is essential. Here, we discuss some problems in systematic review of animal experiments and whether animal models of diverse species contribute to bias of meta-analysis conclusions.
At present, there are many items/checklists used to assess the methodological quality of animal studies. Yet, no tool has been specifically designed for assessing internal validity of animal studies. This articles introduce and interprets SYRCLE's risk of bias tool for animal studies in detail for Chinese scholars to accurately assess the methodological quality of animal studies when they develop systematic reviews on animal studies, so as to provide references for scientific design and implementation of animal studies.
ObjectiveTo systematically review the efficacy and safety of electroacupuncture in animal hyperlipidemia models. MethodsDatabases such as CNKI, WanFang Data, VIP, CBM, PubMed, EMbase and The Cochrane Library (Issue 12, 2013) were searched for studies concerning the efficacy and safety of electroacupuncture in animal hyperlipidemia models up to December 2013. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and assessed the methodological quality of included studies by using reformative CAMARADES List. Then, meta-analysis was performed by using RevMan 5.2 software. ResultsA total of 4 studies involving 89 rats were included. The average score of CAMARADES List was 4. The results of meta-analysis showed that:there were no significant differences between electroacupuncture group and medication group in reducing the levels of TC (MD=0.06, 95%CI -0.08 to 0.20, P=0.40), TG (MD=-0.01, 95%CI -0.08 to 0.06, P=0.74), LDL-C (MD=0.01, 95%CI -0.04 to 0.03, P=0.65) and increasing the level of HDL-C (MD=-0.00, 95%CI -0.09 to 0.08, P=0.93). ConclusionCurrent evidence shows that there are no differences between electroacupuncture and medication in reducing levels of TC, TG, LDL-C and increasing the level of HDL-C in hyperlipidaemia rats. But due to the limitation of sample size of included studies, more large-scale, high quality studies are needed.
ObjectiveTo survey the important characteristics, such as the number of time cited, methodological and reporting quality of the systematic review/meta-analysis (SR/MA) of animal studies published in Chinese journals. MethodsThe CNKI and WanFang Data databases were searched for SR/MA of animal studies published in Chinese journals from inception to March 2014. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted basic characteristic and methodology characteristics of included studies. And then a descriptive analysis was conducted. ResultsA total of 18 studies published in 13 different journals were included. 77.8% studies were not been cited, 44.4% did not report the types of including studies. Besides, there were some certain weaknesses in the methodological quality, for example, over 60% studies did not assess the qualities and publication bias of the including studies, 22.2% SRs/MAs only searched Chinese databases, over 80% studies did not provide flow chart etc. ConclusionThe number of SRs/MAs of animal studies published in Chinese journals is small and the number of times cited is low, and the methodological and reporting quality is poor. So, focusing on improving the quality of SRs/MAs is urgently needed in order to increase the value of these studies.
ObjectiveTo provide a reference for developing search strategy of systematic reviews/meta-analyses (SRs/MAs) of animal researches (ARs) in future, we investigated and analyzed the search strategy of SRs/MAs of ARs at home and abroad. MethodsOvid-MEDLINE, Ovid-EMbase, Ovid-BIOSIS previews, CBM, CNKI, VIP and WanFang Data were searched from inception to January 2015, to collect SRs/MAs of ARs that related to medicine. No limitation in species. Two reviewers independently screened literature, extracted basic characteristics, databases and other sources searched, characteristics of reported search strategy of included studies. ResultA total of 181 SRs/MAs of ARs were finally included. Less than 30% SRs/MAs searched more than three databases, 65.7% reported supplementary retrieval. 86.2% (156/181) SRs/MAs reported search terms, but only 12 reported search strategy; the search terms of 33 studies included specific name of animal, 27 studies used "animal/experimental model/", 20 studies used "limit to animal". 71.3% SRs/MAs reported specific time limitation of searching, 44.2% reported whether limited language, 23.8% of them limited language, and more of these limited to English. ConclusionAt present, there are still some problems in SRs/MAs of ARs at home and abroad when choice database, search terms and search strategy, so we advise that:1) It's necessary to choice typical databases as many as possible according to search field; 2) Using specific animal's name and (or) "animal" as one of search terms, and using "limit to animal" according to characteristic of different databases; 3) The reporting of search strategy of SRs/MAs of ARs should include search sources, time limitation, language limitation, limitation of inclusion type, search terms and complete search strategy, besides, reporting knowledge of reviewers is also necessary; 4) To improve transparency and clarity of SRs/MAs of ARs, some related journals should introduce "reporting complete search strategy" in their instruction for authors.
At present, systematic reviews of animal experimental studies has become a new trend and an important way to synthesize the results of animal experimental studies, improve the conducting and reporting quality of animal experimental studies and provide references for the furture clinical research. However, there are many problems in the design and implementation process of published systematic reviews of animal experimental studies. Therefore, it is important to design a scientific and standard practical process to improve the quality of systematic reviews of animal experimental studies. In this paper, we developed a standard process for systematic reviews of animal experimental studies, in order to improve the quality of systematic reviews of animal experimental studies.
ObjectivesTo survey the current research situation, methodological and reporting quality of the systematic review/meta-analysis (SRs/MAs) of animal studies.MethodsPubMed, EMbase, BIOSIS Previews, CNKI, WanFang Data, CBM and VIP databases were searched to collect SRs/MAs of animal studies from inception to June 2016. Two reviewers independently screened literature, extracted data, a descriptive analysis was then conducted.ResultsA total of 609 SRs/MAs of animal studies were included, which were from 27 countries and published in 526 journals. Merely 36.8% (224/609) studies assessed the risk of bias in the original animal experiments. Less than 50% studies reported the method of literature selection (41.9%, 255/609), data abstraction (32.0%, 195/609) and study characteristics (41.2%, 251/609).ConclusionsThe published SRs/MAs of animal studies is poor in both methodological and reporting quality. Thus, we hope to improve awareness and actual use rates of these guidelines by basic medical researchers and journal editors, thereby improving the quality of animal experimental methods and reporting standards.