![number of studies for a comprehensive meta analysis review number of studies for a comprehensive meta analysis review](https://ars.els-cdn.com/content/image/1-s2.0-S2542519621001492-gr1.gif)
The methodology for these reviews is still under development and will not be considered further in this editorial.
![number of studies for a comprehensive meta analysis review number of studies for a comprehensive meta analysis review](https://www.meta-analysis.com/Images/img125.jpg)
Examples include diagnostic reviews, prognostic reviews, and qualitative reviews. Recently, however many other types of SRs are being done that may not necessarily fit this formula.
![number of studies for a comprehensive meta analysis review number of studies for a comprehensive meta analysis review](https://adc.bmj.com/content/archdischild/90/8/845/F2.large.jpg)
What makes the SR different is that the study data are derived from the reports of completed (and usually published) studies, and it does this in a very systematic way.īefore even starting the process of performing an SR, the authors should clarify their clinical question using the PICO (participants, intervention, comparison, and outcomes) approach. Like any other paper, the SR has an introduction, a methods section, a results section, and a discussion.
![number of studies for a comprehensive meta analysis review number of studies for a comprehensive meta analysis review](https://pishgam-bio.ir/wp-content/uploads/2020/01/metaanalysis.png)
Report the study in such a way as to allow reproducibility of the results (PRISMA) 5 or future updating of the systematic review PROSPERO) 6īe circumspect when interpreting the results acknowledge the sources of bias and consider heterogeneity, generalizability, and contemporary clinical relevance Write a detailed study protocol outlining end points, inclusion criteria, and a search strategy, and publish it in advance on a publically available website (e.g. Include an experienced meta-analyst, content expert (ideally, a triallist), and statistician Is there a need to inform the design and conduct of a definitive, large trial?Īre the findings novel? Has the question been adequately addressed by a previous systematic review (and how recently)?ĭefine the research question clearly and completelyĬheck that the research question is unresolved Is there demonstrable variation in practice? Is the study question clinically important? What is the contemporary relevance of the study question? For the inexperienced, the PRISMA guidelines 5 can be useful, and in any case, it is strongly recommended that the conduct and reporting of the SR be in accordance with its principles. The last of these, ideally, should have led at least one of the clinical trials being included in the analysis. The author team for an SR should include at least one person with some experience in the performance of SRs, one person skilled in statistics, and one person with content knowledge of the topic being addressed. Ideally, the importance of the study is highlighted, considering clinical usefulness and the need for future research (Table 1 ). 5 A good SR also includes a comprehensive and critical discussion of the results, including strengths and limitations, such as assessment of bias, heterogeneity, and used definitions and categorizations. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist will help to include all essential elements ( ). Key elements to increase chances of acceptance include a clear and detailed methodology, with a focus on generalizability and reproducibility. The value of any SR depends heavily on the quantity, quality, and heterogeneity of the included studies, yet a good meta-analysis methodology is at least as important. This editorial has been written in order to help authors and readers understand the basic features of the SR and improve their ability to write and read them critically. 3, 4 However, the acceptance rate for this journal is quite low, indicating a high proportion of low-quality manuscripts. The number and quality of SRs appearing in anaesthesia journals has increased, in part because these provide up-to-date, reliable, and clinically relevant information for readers. The value and credibility of an SR depends on the importance of the question, the quality of the original studies, the efforts undertaken to minimize bias, and the clinical applicability. 1 Clinical decisions should be based on the totality of the best evidence and not the results of individual studies. Meta-analysis is the statistical method used to combine results from the relevant studies, and the resultant larger sample size provides greater reliability (precision) of the estimates of any treatment effect. A systematic review (SR) aims to retrieve, synthesize, and appraise existing knowledge on a particular subject.