Cochrane Handbook for Systematic Reviews of Interventions Version 510
A systematic review (SR) aims to recall, synthesize, and appraise existing knowledge on a particular bailiwick. Meta-assay 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 whatsoever treatment consequence.
Clinical decisions should exist based on the totality of the best evidence and not the results of private studies. 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.
2
- Murad MH
- Montori VM
- Ioannidis JP
- et al.
How to read a systematic review and meta-analysis and apply the results to patient care: users' guides to the medical literature.
- Crossref
- PubMed
- Scopus (274)
- Google Scholar
The number and quality of SRs appearing in anaesthesia journals has increased, in part considering these provide up-to-date, reliable, and clinically relevant information for readers.
,
Nonetheless, the acceptance charge per unit for this journal is quite low, indicating a high proportion of low-quality manuscripts. This editorial has been written in society to assist authors and readers understand the bones features of the SR and amend their ability to write and read them critically.
The value of whatever SR depends heavily on the quantity, quality, and heterogeneity of the included studies, even so a proficient meta-analysis methodology is at to the lowest degree as of import. Primal elements to increase chances of acceptance include a articulate and detailed methodology, with a focus on generalizability and reproducibility. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist volition help to include all essential elements (http://www.prisma-argument.org/PRISMAStatement/PRISMAStatement.aspx).
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. Ideally, the importance of the written report is highlighted, considering clinical usefulness and the need for future enquiry (Table 1).
The author team for an SR should include at to the lowest degree 1 person with some experience in the functioning of SRs, 1 person skilled in statistics, and one person with content knowledge of the topic being addressed. The concluding of these, ideally, should have led at least one of the clinical trials being included in the assay. For the inexperienced, the PRISMA guidelines
tin be useful, and in whatever case, it is strongly recommended that the bear and reporting of the SR be in accord with its principles.
Like any other paper, the SR has an introduction, a methods section, a results section, and a word. What makes the SR different is that the study information are derived from the reports of completed (and usually published) studies, and information technology does this in a very systematic way.
Before even starting the process of performing an SR, the authors should clarify their clinical question using the PICO (participants, intervention, comparison, and outcomes) approach. Recently, however many other types of SRs are being done that may not necessarily fit this formula. Examples include diagnostic reviews, prognostic reviews, and qualitative reviews. The methodology for these reviews is still nether evolution and volition not exist considered further in this editorial.
The clinical question should be described in detail at the protocol stage. The participants are the group of patients to be included. It is important to consider the characteristics of these thoroughly in guild to include the group of patients relevant to the question in focus. The intervention must also be well described, whereas the command can be placebo, no treatment, or standard care. Of course, two different treatments can also be compared. At that place needs to be a nominated main finish point in whatsoever trial, including SRs.
half-dozen
- Tricco Air conditioning
- Cogo Due east
- Page MJ
- et al.
A third of systematic reviews changed or did not specify the primary outcome: a PROSPERO register study.
- Google Scholar
There is no fixed limit for secondary outcomes, simply normally 5 to nine volition exist considered a maximum. The PICO is useful when designing the search strategy for the review. Subgroups and covariates should be carefully considered and prespecified in order to avert information dredging.
7
- Page MJ
- McKenzie JE
- Kirkham J
- et al.
Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions.
- PubMed
- Google Scholar
The search strategy for SRs needs to be comprehensive and include all relevant databases. The well-nigh common databases to search are PubMed (Medline), Cochrane Library CENTRAL, Embase, Cinahl, and LiLacs. As the master involvement is commonly the reported upshot size, it is worthwhile for meta-analyses to consider inclusion of abstracts from major conferences in recent years. The search strategy is part of the review methodology, although for some journals it tin be described as supplementary fabric on the journal website. The search methods need to exist written in such a way that the search tin be repeated past the reader, and by the authors, in case of updating the review.
The review process will start by retrieving and selecting relevant papers for inclusion as described in the protocol. Every paper must be evaluated to determine whether it meets the inclusion criteria. It is recommended to make a table of all included papers, and that the search and screening be done independently by at least two investigators. Double-data extraction past two independently working researchers is recommended to forestall errors.
eight
Finding What Works in Health Care: Standards for Systematic Reviews, 2011 doi: x.17226/13059.
- Google Scholar
The papers need to fulfil inclusion criteria, specified in the methods department of the review. It is useful to provide a menstruation diagram describing the pick of papers for the review.
The SR protocol should be published before starting the review process. For Cochrane reviews, publication of the protocol has been standard process since the foundation of the Cochrane Collaboration in 1993. For other systematic reviews, it is now recommended to publish the protocol on PROSPERO (http://www.crd.york.air-conditioning.united kingdom/prospero/)
half-dozen
- Tricco Air-conditioning
- Cogo Due east
- Page MJ
- et al.
A third of systematic reviews changed or did not specify the main consequence: a PROSPERO register study.
- Google Scholar
or another comparable publically accessible website.
After pick, the papers must exist screened for bias. A useful tool for this procedure is the Cochrane gamble of bias tool,
or AMSTAR.
Careful consideration must precede the performance of the meta-assay in the review. Meta-analysis should be performed merely when appropriate. At that place are two major factors that need to be evaluated before a decision well-nigh meta-analysis is made; one is heterogeneity betwixt studies and the other is the existence of reporting bias.
Heterogeneity arises when the difference between trials is too large. The differences can be in the populations or in the interventions. The amount of heterogeneity can exist quantified using the I 2statistic.
Heterogeneity can also be evaluated visually, by inspecting a forest plot.
,
Although a random-effects meta-assay can account for some heterogeneity, when significant heterogeneity exists, meta-analysis should non be performed.
Reporting bias is bias across trials. Information technology arises when the result of a trial has an impact on the publications process. It is well known that a trial with a positive, pregnant outcome is more likely to be published faster (time lag bias), in a journal with a higher impact cistron (publication bias), in English (language bias) than its non-significant analogue, even if both trials are performed according to the highest standards of methodology. Reporting bias will therefore near ever tend to overestimate the handling effect of an intervention. A funnel plot can be used to assess the amount of reporting bias, inducing asymmetry in the shape of the plot.
Besides, small trial bias occurs considering pocket-size trials tend to overestimate treatment effects, and these typically populate SRs in anaesthesia heavily.
Appropriate selection of treatment effects or adventure estimates, and decisions regarding the use of fixed-effect or random-effects meta-analysis, and the software used,
are important.
Cochrane reviews are frequently published in a newspaper journal equally a co-publication. This is nearly oft done in order to reach a broader audition. Although the printed version of the Cochrane reviews in most instances will exist shorter and more than digestible, the overall methodology and the results and conclusion must remain the aforementioned.
In conclusion, SRs and meta-analyses synthesize and update knowledge on a topic of interest. The methodology should also exist presented conspicuously and in sufficient detail, and the strength of the bear witness should be evaluated charily.
References
- Cochrane Handbook for Systematic Reviews of Interventions. 2011 ()
-
How to read a systematic review and meta-analysis and use the results to patient intendance: users' guides to the medical literature.
JAMA. 2014; 312 : 171-179 -
Clinical relevance in anesthesia journals.
Curr Opin Anaesthesiol. 2006; nineteen : 166-170 -
Characteristics of meta-analyses related to credence for publication in a medical journal.
J Clin Epidemiol. 2001; 54 : 655-660 -
Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
J Clin Epidemiol. 2009; 62 : 1006-1012 -
A 3rd of systematic reviews changed or did not specify the master outcome: a PROSPERO register study.
J Clin Epidemiol. 2016; () -
Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions.
Cochrane Database Syst Rev. 2014; 10 : MR000035 -
Finding What Works in Health Care: Standards for Systematic Reviews, 2011 doi: 10.17226/13059.
-
The Cochrane Collaboration'due south tool for assessing risk of bias in randomised trials.
Br Med J. 2011; 343 : d5928 -
AMSTAR is a reliable and valid measurement tool to assess the methodological quality of systematic reviews.
J Clin Epidemiol. 2009; 62 : 1013-1020 -
Measuring inconsistency in meta-analyses.
Br Med J. 2003; 327 : 557-560 -
How to read a forest plot in a meta-assay.
Br Med J. 2015; 351 : h4028 -
Funnel plots for detecting bias in meta-assay: guidelines on choice of axis.
J Clin Epidemiol. 2001; 54 : 1046-1055 -
A basic introduction to fixed-result and random-effects models for meta-assay.
Res Synth Methods. 2010; 1 : 97-111 -
Influence of trial sample size on treatment effect estimates: meta-epidemiological study.
Br Med J. 2013; 346 : f2304 -
A systematic comparing of software dedicated to meta-analysis of causal studies.
BMC Med Res Methodol. 2007; vii : forty
Article Info
Identification
DOI: https://doi.org/10.1093/bja/aew264
Copyright
© 2016 The Author(s). Published by Elsevier Inc.
User License
Elsevier user license |How you tin reuse 
Permitted
For non-commercial purposes:
- Read, print & download
- Text & data mine
- Translate the commodity
Not Permitted
- Reuse portions or extracts from the article in other works
- Redistribute or republish the concluding article
- Sell or re-use for commercial purposes
Elsevier's open access license policy
ScienceDirect
Access this commodity on ScienceDirect- View Large Image
- Download Hi-res image
Related Articles
spellmanaffew2001.blogspot.com
Source: https://www.bjanaesthesia.org.uk/article/S0007-0912(17)30161-7/fulltext
0 Response to "Cochrane Handbook for Systematic Reviews of Interventions Version 510"
Post a Comment