Systematic review of literature
Wikipedia, the free to: navigation, the academic journal, see systematic atic reviews are types of literature reviews that collect and critically analyze multiple research studies or papers, using methods that are selected before one or more research questions are formulated, and then finding and analyzing studies that relate to and answer those questions in a structured methodology. 1] they are designed to provide a complete, exhaustive summary of current literature relevant to a research question. Systematic reviews of randomized controlled trials are key in the practice of evidence-based medicine, and a review of existing studies is often quicker and cheaper than embarking on a new understanding of systematic reviews, and how to implement them in practice, is highly recommended for professionals involved in the delivery of health care. Besides health interventions, systematic reviews may examine clinical tests, public health interventions, environmental interventions, social interventions, adverse effects, and economic evaluations. 4] systematic reviews are not limited to medicine and are quite common in all other sciences where data are collected, published in the literature, and an assessment of methodological quality for a precisely defined subject would be helpful. Systematic review aims to provide a complete, exhaustive summary of current literature relevant to a research question.
Systematic literature reviews
The first step in conducting a systematic review is to create a structured question to guide the review. 7] the second step is to perform a thorough search of the literature for relevant papers. The methodology section of a systematic review will list all of the databases and citation indexes that were searched such as web of science, embase, and pubmed and any individual journals that were searched. Each included study may be assigned an objective assessment of methodological quality preferably by using methods conforming to the preferred reporting items for systematic reviews and meta-analyses (prisma) statement (the current guideline) or the high quality standards of cochrane. Reviews often, but not always, use statistical techniques (meta-analysis) to combine results of eligible studies, or at least use scoring of the levels of evidence depending on the methodology used. 6] systematic review is often applied in the biomedical or healthcare context, but it can be applied in any field of research.
Groups like the campbell collaboration are promoting the use of systematic reviews in policy-making beyond just healthcare. Systematic review uses an objective and transparent approach for research synthesis, with the aim of minimizing bias. While many systematic reviews are based on an explicit quantitative meta-analysis of available data, there are also qualitative reviews which adhere to standards for gathering, analyzing and reporting evidence. 10] the eppi-centre has been influential in developing methods for combining both qualitative and quantitative research in systematic reviews. 11] the prisma statement suggests a standardized way to ensure a transparent and complete reporting of systematic reviews, and is now required for this kind of research by more than 170 medical journals worldwide. 15] these approaches try to overcome the problems of methodological and epistemological heterogeneity in the diverse literatures existing on some subjects.
Main stages of a systematic review are:Defining a question and agreeing an objective method. These stages are complete, the review may be published, disseminated and translated into practice after being adopted as cochrane is a group of over 37,000 specialists in healthcare who systematically review randomised trials of the effects of prevention, treatments and rehabilitation as well as health systems interventions. Cochrane reviews are published in the cochrane database of systematic reviews section of the cochrane library. Reviews assess the benefits and harms of interventions used in healthcare and health stic test accuracy reviews assess how well a diagnostic test performs in diagnosing and detecting a particular ology reviews address issues relevant to how systematic reviews and clinical trials are conducted and ative reviews synthesize qualitative and quantitative evidence to address questions on aspects other than effectiveness. Reviews address the probable course or future outcome(s) of people with a health ews of systematic reviews (oors) are a new type of study in order to compile multiple evidence from systematic reviews into a single document that is accessible and useful to serve as a friendly front end for the cochrane collaboration with regard to healthcare cochrane collaboration provides a handbook for systematic reviewers of interventions which "provides guidance to authors for the preparation of cochrane intervention reviews. The review question(s) and developing criteria for including ing for ing studies and collecting ing risk of bias in included ing data and undertaking sing reporting ting results and "summary of findings" reting results and drawing cochrane handbook forms the basis of two sets of standards for the conduct and reporting of cochrane intervention reviews (mecir - methodological expectations of cochrane intervention reviews).
24] the lines within illustrate the summary results from an iconic systematic review showing the benefit of corticosteroids, which 'has probably saved thousands of premature babies'. The campbell collaboration "helps people make well-informed decisions by preparing, maintaining and disseminating systematic reviews in education, crime and justice, social welfare and international development. Systematic reviews are regarded as the strongest form of medical evidence, a review of 300 studies found that not all systematic reviews were equally reliable, and that their reporting can be improved by a universally agreed upon set of standards and guidelines. 28] a further study by the same group found that of 100 systematic reviews monitored, 7% needed updating at the time of publication, another 4% within a year, and another 11% within 2 years; this figure was higher in rapidly changing fields of medicine, especially cardiovascular medicine. 29] a 2003 study suggested that extending searches beyond major databases, perhaps into grey literature, would increase the effectiveness of reviews. And colleagues highlighted the problems with systematic reviews, particularly those conducted by the cochrane, noting that published reviews are often biased, out of date and excessively long.
31] they criticized cochrane reviews as not being sufficiently critical in the selection of trials and including too many of low quality. They proposed several solutions, including limiting studies in meta-analyses and reviews to registered clinical trials, requiring that original data be made available for statistical checking, paying greater attention to sample size estimates, and eliminating dependence on only published of these difficulties were noted early on as described by altman: "much poor research arises because researchers feel compelled for career reasons to carry out research that they are ill equipped to perform, and nobody stops them. 33] another concern is that the methods used to conduct a systematic review are sometimes changed once researchers see the available trials they are going to include. 34] bloggers have described retractions of systematic reviews and published reports of studies included in published systematic reviews. 38] subsequently, a number of donors – most notably the uk department for international development (dfid) and ausaid – are focusing more attention and resources on testing the appropriateness of systematic reviews in assessing the impacts of development and humanitarian interventions. Institute of medicine (us) committee on standards for systematic reviews of comparative effectiveness, research; eden, j; levit, l; berg, a; morton, s (2011).
The prisma statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration". Tensions and paradoxes in electronic patient record research: a systematic literature review using the meta-narrative method". Overview of systematic reviews - a new type of study: part i: why and for whom? Bias due to selective inclusion and reporting of outcomes and analyses in systematic reviews of randomised trials of healthcare interventions". Resources ces in your dia commons has media related to systematic for reviews and dissemination, university of ne ce for policy and practice information and co-ordinating centre (eppi-centre), university of : review literature—articles about the review : review [publication type] - limit search results to search: "review literature" [majr]. Reporting items for systematic reviews and meta-analyses (prisma) statement, "an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses".
Nunn, jack (2015-10-01), english: this video explains why systematic reviews are important and how they are done. Retrieved ries: systematic reviewreview journalsevidence-based practicesinformation sciencemedical researchmeta-analysisnursing researchhidden categories: wikipedia articles needing page number citations from june logged intalkcontributionscreate accountlog pagecontentsfeatured contentcurrent eventsrandom articledonate to wikipediawikipedia out wikipediacommunity portalrecent changescontact links hererelated changesupload filespecial pagespermanent linkpage informationwikidata itemcite this a bookdownload as pdfprintable version. Pmcid: pmc539417five steps to conducting a systematic reviewkhalid s khan, mb msc, regina kunz, md msc,1 jos kleijnen, md phd,2 and gerd antes, phd3education resource centre, birmingham women's hospital, birmingham b15 2tg, uk1 german cochrane centre, freiburg and department of nephrology, charité, berlin, germany2 centre for reviews and dissemination, york, uk3 german cochrane centre, freiburg, germany correspondence to: khalid s khan e-mail:-mahb@author information ► copyright and license information ►copyright © 2003, the royal society of medicinethis article has been cited by other articles in atic reviews and meta-analyses are a key element of care, yet they remain in some ways mysterious. Review earns the adjective systematic if it is based on a ated question, identifies relevant studies, appraises their quality izes the evidence by use of explicit methodology. Reviews should never be any other this paper we provide a step-by-step explanation—there are steps—of the methods behind reviewing, and the quality nt in each step (box 1). For purposes of illustration we use a concerning the safety of public water fluoridation, but we ize that our subject is review methodology, not e: safety of public water fluoridationyou are a public health professional in a locality that has public dation.
The n various components of the question and the structure of the are shown in figure paper focuses only on the question of safety related to es described 1structured questions for systematic reviews and relations on components in a comparative studybox 1 the steps in a systematic reviewstep 1: framing questions for a reviewthe problems to be addressed by the review should be specified in the clear, unambiguous and structured questions before beginning the . Once the review questions have been set, modifications to the be allowed only if alternative ways of defining the populations,Interventions, outcomes or study designs become apparentstep 2: identifying relevant workthe search for studies should be extensive. Multiple resources (erized and printed) should be searched without language study selection criteria should flow directly from the review be specified a priori. Reasons for inclusion and exclusion recordedstep 3: assessing the quality of studiesstudy quality assessment is relevant to every step of a review. With ound, systematic reviews on safety have to include evidence from a range of 2: identifying relevant publicationsto capture as many relevant citations as possible, a wide range of medical,Environmental and scientific databases were searched to identify s of the effects of water fluoridation. Thus, systematic reviews assessing the safety of entions have to include evidence from a broader range of study eration of the type and amount of research likely to be available led ion of comparative studies of any design.
Thus ce summarized in this review is likely to be as good as it will get foreseeable future. The interpretation of the results may lly limited because of the low quality of studies, but the findings cancer outcomes are supported by the moderate-quality tionafter having spent some time reading and understanding the review, you sed by the sheer amount of published work relevant to the question . From the review you also discovered fluorosis (mottled teeth) was related to concentration of the interest groups raise the issue of safety again, you will be able e that there is no evidence to link cancer with dation; however, you will have to come clean about the risk of sis, which appears to be dose dependent, and you may want to measure de concentration in the water supply and share this information with st ability to quantify the safety concerns of your population through , albeit from studies of moderate to low quality, allows your ity, the politicians and the public to consider the balance cial and harmful effects of water fluoridation. Whatever the opinions on this matter, you are able to reassure s that there is no evidence that fluoridation of drinking ses the risk of sionwith increasing focus on generating guidance and recommendations ce through systematic reviews, healthcare professionals need tand the principles of preparing such reviews.