Systematic review is a type of library review that uses systematic methods to collect secondary data, assess critical research studies, and synthesize studies. Systematic reviews formulate broad or narrow research questions within the scope, and identify and synthesize studies directly related to systematic review questions. They are designed to provide a complete and complete summary of current evidence relevant to the research question. A systematic review of randomized controlled trials is key to evidence-based medical practice, and existing study reviews are often faster and cheaper than starting a new study.
Understanding of systematic reviews, and how to apply them in practice, is highly recommended for professionals involved in health care delivery. In addition to health interventions, a systematic review can examine clinical trials, public health interventions, environmental interventions, social interventions, adverse events, and economic evaluations. The systematic review is not limited to drugs and is quite common in all the other sciences in which data are collected, published in the literature, and the methodological quality assessment for a properly defined subject will be helpful.
Video Systematic review
Characteristics
The systematic review aims to provide a complete and complete summary of the current literature relevant to the research question. The first step in doing a systematic review is to create a structured question to guide the review. The second step is to search the entire literature for relevant papers. The Systematic Methodology section of the systematic review will list all the database and quote indexes searched for such as Web of Science, Embase, and PubMed and each individual journal sought. The titles and abstracts of the identified articles are examined against predetermined criteria for eligibility and relevance to establish inclusion sets. This set will reconnect with the research problem. Each included study may be subjected to objective assessment of methodological quality by using appropriate methods with Preferred Reporting Items for Systematic Review and Meta Analysis (PRISMA) statements (current guidelines) or Cochrane high quality standards.
Systematic reviews are often, but not always, using statistical techniques (meta-analysis) to combine eligible study results, or at least using an evidence-level assessment depending on the methodology used. Additional assessors may be consulted to resolve the assessment differences between the assessors. Systematic reviews are often applied in the context of biomedicine or health care, but can be applied in all areas of research. Groups like Campbell Collaboration promote the use of systematic reviews in policy making beyond health care alone.
The systematic review uses an objective and transparent approach to research synthesis, with the aim of minimizing bias. While many systematic reviews are based on quantitative quantitative meta-analysis of available data, there are also qualitative reviews that adhere to standards for collecting, analyzing and reporting evidence. The EPPI-Center has been instrumental in developing methods for combining qualitative and quantitative research in systematic reviews. The PRISMA statement shows a standard way to ensure transparent and complete systematic reporting, and is now required for such research by more than 170 medical journals worldwide.
The development of a systematic review during the 21st century includes both a realist review and a meta-narrative approach, both of which address the problem of methods and heterogeneity that exist on some subjects.
Maps Systematic review
Stages
The main stages of systematic review are:
- Define the question and agree on the objective method.
- Search for relevant data from research matching certain criteria. For example, just choose a good quality research and answer the question specified.
- 'Extraction' of relevant data. This may include how the study was conducted (often called a method or 'intervention'), who participated in the research (including how many people), how paid for (eg funding source) and what happened (outcome).
- Assess the quality of data by judging by the criteria identified in the first step.
- Analyze and merge data (using complex statistical methods) that gives the overall result of all data. This data combination can be visualized using a blobbogram (also called a forest plot). The diamond on the blobbogram shows the combined results of all the data included. Because these combined results use data from more sources than just a single set of data, it is considered more reliable and better evidence, as more and more data exists, the more we can conclude.
After these stages are completed, the review may be published, disseminated and translated into practice after adoption as evidence.
Field of research
Medicine and biology
The Cochrane is a group of over 37,000 specialists in health care that systematically review randomized trials of the effects of prevention, care and rehabilitation as well as health system interventions. If necessary, they also include other types of research results. Cochrane reviews are published at The Cochrane Database of Systematic Reviews part of the Cochrane Library. The 2015 impact factor for The Cochrane Database of Systematic Reviews is 6.103, and it is ranked 12th in the category of "Medicine, General & Internal". There are six types of Cochrane Review:
- The intervention review assesses the benefits and hazards of interventions used in health and health care policies.
- Reviews of diagnostic test accuracy assess how well diagnostic tests perform in diagnosing and detecting specific diseases.
- Methodology Reviews address issues relevant to how systematic reviews and clinical trials are conducted and reported.
- A qualitative review synthesizes qualitative and quantitative evidence to answer questions on aspects other than effectiveness.
- Prognosis review indicates possible future results or results of people experiencing health problems.
- Systematic Review Overview (OoRs) is a new type of study to gather a lot of evidence from systematic reviews into an accessible and useful document to serve as a friendly front end for Cochrane Collaboration with respect to decision making health care.
Cochrane Collaboration provides a handbook for systematic review of interventions that "provide guidance to the authors for the preparation of Cochrane Intervention reviews." The Cochrane Handbook outlines eight general steps to prepare a systematic review:
- Determine the review question and develop criteria for entering the study
- Search for study
- Select study and collect data
- Assess risk of bias in included study
- Analyze data and perform meta-analysis
- Overcoming reporting bias
- Presents the results and "summary findings" table
- Interpret results and draw conclusions
The Cochrane Handbook forms the basis of two sets of standards for the behavior and reporting of Cochrane Intervention Reviews (MECIR - Expectations of Cochrane Intervention Reviews methodology)
The Cochrane Collaboration logo visually shows how the results of some systematic reviews can be explained. The lines in illustrate the summary results of an iconic systematic review showing the benefits of corticosteroids, which 'may have saved thousands of premature babies'.
Social science
Quasi-standards for systematic review in social science are based on the procedure proposed by the Campbell Collaboration, which is one of a number of groups promoting evidence-based policies in the social sciences. Campbell's Collaboration "helps people make well-informed decisions by preparing, maintaining and disseminating systematic reviews in education, crime and justice, social welfare and international development.This is a brother initiative of Cochrane.Campbell collaboration was created in 2000 and the inaugural meeting in Philadelphia, USA, attracted 85 participants from 13 countries.
Business and economy
Due to the different nature of the field of research beyond the natural sciences, such methodological measures can not be easily applied in business research. The initial attempt to transfer procedures from drugs to business research has been made by Tranfield et al. (2003). A step-by-step approach has been developed by Durach et al. Based on the experiences they make in their own discipline, these authors have adapted the methodological steps and developed standardized procedures for conducting systematic literature review in business and economics.
Strengths and weaknesses
While systematic reviews are considered the strongest form of medical evidence, a review of 300 studies found that not all systematic reviews are equally reliable, and that their reporting can be enhanced by a universally agreed set of standards and guidelines. A further study by the same group found that out of 100 systematic reviews monitored, 7% needed renewal at the time of publication, another 4% in a year, and 11% in 2 years; This figure is higher in the rapidly changing medical field, especially cardiovascular drugs. A 2003 study suggested that expanding searches outside the main database, possibly into the gray literature, would improve the effectiveness of the review.
Roberts and colleagues highlight the problem with a systematic review, especially those conducted by Cochrane, noting that published reviews are often biased, out of date and too long. They criticized the Cochrane review for not being critical enough in the selection of trials and including too much low quality. They proposed several solutions, including limiting studies in meta-analyzes and reviews for registered clinical trials, which required original data to be available for statistical checking, paying more attention to sample size estimates, and eliminating reliance on only published data.
Some of these difficulties are noted early on as described by Altman: "a lot of bad research came about because researchers felt compelled for career reasons to do research they were not prepared to do, and nothing stopped them." Methodological limitations of meta-analysis have also been noted. Another concern is that the methods used to conduct systematic reviews sometimes change when researchers look at the available trials they will enter. Blogger has described the systematic revocation of systematic review and published a study report which is included in a published systematic review.
Systematic reviews are increasing in other areas, such as international development research. Furthermore, a number of donors - notably the UK Department for International Development (DFID) and AusAid - are more focused and resources to examine systematic appraisal conformity in assessing development impacts and humanitarian interventions.
See also
- Critical appraisal
- Evidence-based research
- Further research is required
- Library review
- Live Reviews
- The colleague review
- Review the journal
- Generalized model aggregation (GMA)
References
External links
- The Center for Review and Dissemination, University of York.
- Cochrane Collaboration
- Evidence for the Information Policy and Practice and Coordination Center (EPPI-Center), University of London
- MeSH: Literature Review - article on the review process
- MeSH: Review [Publication Type] - limit search results to reviews
- PubMed Search: "Review Literature" [MAJR]
- Selected Reporting Items for Systematic Review and Meta-Analysis Reviews (PRISMA), "a set of evidence-based minimum items for reporting in systematic review and meta-analysis"
- Storyboard Animation: What Is A Systematic Review? - Cochrane Consumers and Communication Group
- What is the Systematic review? - Video by Cochrane Consumers and Communication Group
Source of the article : Wikipedia
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