Systematic reviews and meta-analysis

2021 ◽  
pp. 193-206
Author(s):  
Nandi Siegfried ◽  
Lawrence Mbuagbaw
Keyword(s):  
Systematic Reviews ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Research Question ◽  
Similar Data ◽  
Inaccurate Information ◽  
Healthcare Decision Making ◽  
Scoping Reviews ◽  
Meta Analyses

Systematic reviews play an important role in healthcare decision-making. When conducted correctly, they provide up-to-date, comprehensive, and replicable summaries of evidence. Authors of systematic reviews are expected to develop a protocol that outlines the research question and key methodological features of their review. A comprehensive and exhaustive search should be conducted, followed by screening to capture studies that meet the prespecified inclusion criteria. Once the relevant studies have been identified, data will be extracted, using a dedicated tool that permits the review authors to confirm the eligibility of the study and collect information on its design, risk of bias, and results. Sufficiently similar data may be pooled using meta-analytic techniques or synthesized narratively. A summary of the overall quality of evidence for each outcome is an essential component of a systematic review. The main concerns with systematic reviews are (1) selection bias: systematic exclusion of relevant studies due to publication status or language; (2) indexing bias: failure to identify relevant studies because they are not indexed accurately; and (3) information bias: missing or inaccurate information in the included studies. Other approaches to evidence synthesis include mapping the evidence with scoping reviews; conducting overviews of systematic reviews; using individual patient data; conducting network meta-analyses for multiple comparisons; conducting rapid reviews when evidence is needed urgently; synthesis of diagnostic accuracy data; and synthesis of qualitative data. Systematic reviews often inform clinical guidelines and require careful planning and execution by teams with content and methodological expertise.

Review Article: The Flagship of Evidence-Based Medicine

2021 ◽  
pp. 153473462199563
Author(s):  
Miltos K. Lazarides ◽  
Irene-Zacharo Lazaridou ◽  
Nikolaos Papanas
Keyword(s):  
Systematic Reviews ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Evidence Based ◽  
Relevant Evidence ◽  
Quantitative Studies ◽  
Current State ◽  
Scoping Reviews ◽  
Based Medicine

Global literature is ever-growing and physicians rely on it for evidence-based decision making. Review articles summarize available literature and provide the current state of knowledge on a given topic. Various review types exist, the main ones being narrative and systematic reviews. The former are based on studies selected in an undefined manner. They express the authors’ opinions of a given topic, lack a systematic search, and are prone to bias. By contrast, the latter represent an unbiased synthesis of knowledge on a particular topic and attempt to offer all relevant evidence. A systematic review may include a meta-analysis, which combines the results of quantitative studies using statistical techniques to provide a more precise summary of the evidence. With a dramatic increase in literature complexity, new “next-generation” types of reviews emerged to improve the quality of evidence synthesis: network meta-analysis, umbrella review, and meta-analysis of individual patient data, among others. Finally, scoping reviews are a special type, conducted as precursors to systematic reviews aiming to reveal specific knowledge gaps in a given subject.

scholarly journals Comparative Effectiveness Research: Using Systematic Reviews and Meta-Analyses to Synthesize Empirical Evidence

2011 ◽  
Vol 25 (3) ◽  
pp. 191-209 ◽  
Author(s):  
Maria C. Katapodi ◽  
Laurel L. Northouse
Keyword(s):  
Systematic Reviews ◽  
Comparative Effectiveness Research ◽  
Comparative Effectiveness ◽  
Meta Analysis ◽  
Research Question ◽  
Alternative Methods ◽  
Evidence Based ◽  
Effectiveness Research ◽  
Meta Analyses ◽  
Research Studies

The increased demand for evidence-based health care practices calls for comparative effectiveness research (CER), namely the generation and synthesis of research evidence to compare the benefits and harms of alternative methods of care. A significant contribution of CER is the systematic identification and synthesis of available research studies on a specific topic. The purpose of this article is to provide an overview of methodological issues pertaining to systematic reviews and meta-analyses to be used by investigators with the purpose of conducting CER. A systematic review or meta-analysis is guided by a research protocol, which includes (a) the research question, (b) inclusion and exclusion criteria with respect to the target population and studies, © guidelines for obtaining relevant studies, (d) methods for data extraction and coding, (e) methods for data synthesis, and (f ) guidelines for reporting results and assessing for bias. This article presents an algorithm for generating evidence-based knowledge by systematically identifying, retrieving, and synthesizing large bodies of research studies. Recommendations for evaluating the strength of evidence, interpreting findings, and discussing clinical applicability are offered.

scholarly journals Systematic Reviews and Meta-analysis Published in Indexed Portuguese Medical Journals: Time Trends and Critical Appraisal.

2021 ◽  
Author(s):  
Luísa Prada ◽  
Ana Prada ◽  
Miguel Antunes ◽  
Ricardo Fernandes ◽  
João Costa ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Critical Appraisal ◽  
Data Extraction ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Measurement Tool ◽  
Medical Journals ◽  
Electronic Search ◽  
Potential Impact

Abstract Introduction:Over the last years, the number of systematic reviews published is steadily increasing due to the global interest in this type of evidence synthesis. However, little is known about the characteristics of this research published in Portuguese medical journals. This study aims to evaluate the publication trends and overall quality of these systematic reviews.Material and Methods:Systematic reviews were identified through an electronic search up to August 2020, targeting Portuguese Medical journals indexed in MEDLINE. Systematic reviews selection and data extraction were done independently by three authors. The overall quality critical appraisal using the A MeaSurement Tool to Assess systematic Reviews (AMSTAR II) was independently assessed by three authors. Disagreements were solved by consensus.Results:Seventy systematic reviews published in 5 Portuguese medical journals were included. Most (n=57; 81,4%) were systematic reviews without meta-analysis. Until 2010, the number of systematic reviews per year increased. Since then, the number of reviews published has not remained stable and no less than 3 SRs were published per year. According to the systematic reviews’ typology, most have been predominantly conducted to assess the effectiveness of health interventions (n=28; 40,0%). General and Internal Medicine (n=26; 37,1%) was the most addressed field. Most systematic reviews (n=45; 64,3%) were rated as being of “critically low-quality”.Conclusions:There were consistent flaws in the methodological quality report of the systematic reviews included, particularly in establishing a prior protocol and not assessing the potential impact of the risk of bias on the results.Through the years, the number of systematic reviews published increased, yet their quality is suboptimal. There is a need to improve the reporting of systematic reviews in Portuguese medical journals, which can be achieved by better adherence to quality checklists/tools.Systematic review registration: INPLASY202090105

Systematic Reviews and Meta-analyses

2018 ◽  
Vol 157 (04) ◽  
pp. 392-399
Author(s):  
Sebastian Scheidt ◽  
Patrick Vavken ◽  
Cornelius Jacobs ◽  
Sebastian Koob ◽  
Davide Cucchi ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Scientific Knowledge ◽  
Literature Search ◽  
Meta Analysis ◽  
Review Article ◽  
Systematic Literature Search ◽  
Meta Analyses

AbstractThe rising number of medical publications makes it difficult to keep up-to-date on scientific knowledge. In recent years, reviews in the form of narrative or systematic publications and meta-analyses have increased. These can only be interpreted and evaluated if the reader understands the techniques used. This review article describes the differences between narrative and systematic reviews, together with the characteristics of meta-analysis, and discusses their interpretation. The concept of systematic reviews and meta-analysis includes a systematic literature search and summary, together with an appraisal of the quality of the publications. Systematic reviews are often considered to be original studies due to their structure and ability to reduce bias.

scholarly journals Systematic Reviews and Meta-Analysis in Spine Surgery—How Good Are They in Methodological Quality? A Systematic Review

2020 ◽  
pp. 219256822090681 ◽  
Author(s):  
Muthu Sathish ◽  
Ramakrishnan Eswar
Keyword(s):  
Systematic Review ◽  
Spine Surgery ◽  
Systematic Reviews ◽  
Methodological Quality ◽  
Meta Analysis ◽  
Eligibility Criteria ◽  
Cochrane Database ◽  
Critical Flaw ◽  
Meta Analyses

Study Design: Systematic review. Objectives: To assess the methodological quality of systematic reviews and meta-analyses in spine surgery over the past 2 decades. Materials and Methods: We conducted independent and in duplicate systematic review of the published systematic reviews and meta-analyses between 2000 and 2019 from PubMed Central and Cochrane Database pertaining to spine surgery involving surgical intervention. We searched bibliographies to identify additional relevant studies. Methodological quality was evaluated with AMSTAR score and graded with AMSTAR 2 criteria. Results: A total of 96 reviews met the eligibility criteria, with mean AMSTAR score of 7.51 (SD = 1.98). Based on AMSTAR 2 criteria, 13.5% (n = 13) and 18.7% (n = 18) of the studies had high and moderate level of confidence of results, respectively, without any critical flaws. A total of 29.1% (n = 28) of the studies had at least 1 critical flaw and 38.5% (n = 37) of the studies had more than 1 critical flaw, so that their results have low and critically low confidence, respectively. Failure to analyze the conflict of interest of authors of primary studies included in review and lack of list of excluded studies with justification were the most common critical flaw. Regression analysis demonstrated that studies with funding and studies published in recent years were significantly associated with higher methodological quality. Conclusion: Despite improvement in methodological quality of systematic reviews and meta-analyses in spine surgery in current decade, a substantial proportion continue to show critical flaws. With increasing number of review articles in spine surgery, stringent measures must be taken to adhere to methodological quality by following PRISMA and AMSTAR guidelines to attain higher standards of evidence in published literature.

scholarly journals 10 easy steps to conducting transparent, reproducible meta-analyses for infant researchers

2021 ◽  
Author(s):  
Loretta Gasparini ◽  
Sho Tsuji ◽  
Christina Bergmann
Keyword(s):  
Developmental Psychology ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Research Question ◽  
The Body ◽  
Effect Sizes ◽  
Robust Methods ◽  
Meta Analyses ◽  
Analytic Models

Meta-analyses provide researchers with an overview of the body of evidence in a topic, with quantified estimates of effect sizes and the role of moderators, and weighting studies according to their precision. We provide a guide for conducting a transparent and reproducible meta-analysis in the field of developmental psychology within the framework of the MetaLab platform, in 10 steps: 1) Choose a topic for your meta-analysis, 2) Formulate your research question and specify inclusion criteria, 3) Preregister and carefully document all stages of your meta-analysis, 4) Conduct the literature search, 5) Collect and screen records, 6) Extract data from eligible studies, 7) Read the data into analysis software and compute effect sizes, 8) Create meta-analytic models to assess the strength of the effect and investigate possible moderators, 9) Visualize your data, 10) Write up and promote your meta-analysis. Meta-analyses can inform future studies, through power calculations, by identifying robust methods and exposing research gaps. By adding a new meta-analysis to MetaLab, datasets across multiple topics of developmental psychology can be synthesized, and the dataset can be maintained as a living, community-augmented meta-analysis to which researchers add new data, allowing for a cumulative approach to evidence synthesis.

scholarly journals Evidence-Based Medicine, Systematic Reviews, and Guidelines in Interventional Pain Management: Part 6. Systematic Reviews and Meta-Analyses of Observational Studies

2008 ◽  
Vol 5;12 (5;9) ◽  
pp. 819-850
Author(s):  
Laxmaiah Manchikanti
Keyword(s):  
Systematic Review ◽  
Systematic Reviews ◽  
Evidence Based Medicine ◽  
Observational Studies ◽  
Meta Analysis ◽  
Evidence Based ◽  
Confounding Bias ◽  
Meta Analyses ◽  
Based Medicine

Observational studies provide an important source of information when randomized controlled trials (RCTs) cannot or should not be undertaken, provided that the data are analyzed and interpreted with special attention to bias. Evidence-based medicine (EBM) stresses the examination of evidence from clinical research and describes it as a shift in medical paradigm, in contrast to intuition, unsystematic clinical experience, and pathophysiologic rationale. While the importance of randomized trials has been created by the concept of the hierarchy of evidence in guiding therapy, much of the medical research is observational. The reporting of observational research is often not detailed and clear enough with insufficient quality and poor reporting, which hampers the assessment of strengths and weaknesses of the study and the generalizability of the mixed results. Thus, in recent years, progress and innovations in health care are measured by systematic reviews and meta-analyses. A systematic review is defined as, “the application of scientific strategies that limit bias by the systematic assembly, clinical appraisal, and synthesis of all relevant studies on a specific topic.” Meta-analysis usually is the final step in a systematic review. Systematic reviews and meta-analyses are labor intensive, requiring expertise in both the subject matter and review methodology, and also must follow the rules of EBM which suggests that a formal set of rules must complement medical training and common sense for clinicians to integrate the results of clinical research effectively. While expertise in the review methods is important, the expertise in the subject matter and technical components is also crucial. Even though, systematic reviews and meta-analyses, specifically of RCTs, have exploded, the quality of the systematic reviews is highly variable and consequently, the opinions reached of the same studies are quite divergent. Numerous deficiencies have been described in methodologic assessment of the quality of the individual articles. Consequently, observational studies can provide an important complementary source of information, provided that the data are analyzed and interpreted in the context of confounding bias to which they are prone. Appropriate systematic reviews of observational studies, in conjunction with RCTs, may provide the basis for elimination of a dangerous discrepancy between the experts and the evidence. Steps in conducting systematic reviews of observational studies include planning, conducting, reporting, and disseminating the results. MOOSE, or Meta-analysis of Observational Studies in Epidemiology, a proposal for reporting contains specifications including background, search strategy, methods, results, discussion, and conclusion. Use of the MOOSE checklist should improve the usefulness of meta-analysis for authors, reviewers, editors, readers, and decision-makers. This manuscript describes systematic reviews and meta-analyses of observational studies. Authors frequently utilize RCTs and observational studies in one systematic review; thus, they should also follow the reporting standards of the Quality of Reporting of Meta-analysis (QUOROM) statement, which also provides a checklist. A combined approach of QUOROM and MOOSE will improve reporting of systematic reviews and lead to progress and innovations in health care. Key words: Observational studies, evidence-based medicine, systematic reviews, metaanalysis, randomized trials, case-control studies, cross-sectional studies, cohort studies, confounding bias, QUOROM, MOOSE

scholarly journals Mapping Host-Related Correlates of Influenza Vaccine-Induced Immune Response: An Umbrella Review of the Available Systematic Reviews and Meta-Analyses

Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 215 ◽  
Author(s):  
Alexander Domnich ◽  
Ilaria Manini ◽  
Giovanna Elisa Calabrò ◽  
Chiara de Waure ◽  
Emanuele Montomoli
Keyword(s):  
Influenza Vaccine ◽  
Systematic Reviews ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Health Condition ◽  
Vitamin D Supplementation ◽  
Umbrella Review ◽  
Related Factors ◽  
Ready Availability ◽  
Meta Analyses

Seasonal influenza is the leading infectious disease in terms of its health and socioeconomic impact. Annual immunization is the most efficient way to reduce this burden. Several correlates of influenza vaccine-induced protection are commonly used, owing to their ready availability and cheapness. Influenza vaccine-induced immunogenicity is a function of host-, virus- and vaccine-related factors. Host-related factors constitute the most heterogeneous group. The objective of this study was to analyze the available systematic evidence on the host factors able to modify influenza vaccine-induced immunogenicity. An umbrella review approach was undertaken. A total of 28 systematic reviews/meta-analyses were analyzed—these covered the following domains: intravenous drug use, psychological stress, acute and chronic physical exercise, genetic polymorphisms, use of pre-/pro-/symbiotics, previous Bacillus Calmette–Guérin vaccination, diabetes mellitus, vitamin D supplementation/deficiency, latent cytomegalovirus infection and various forms of immunosuppression. In order to present effect sizes on the same scale, all possible meta-analyses were re-performed and cumulative evidence synthesis ranking was carried out. The meta-analysis was conducted separately on each health condition category and virus (sub)type. A total of 97 pooled estimates were used in order to construct an evidence-based stakeholder-friendly map. The principal public health implications are discussed.

Living systematic reviews: A novel mechanism for improving efficiency and quality of evidence synthesis in oncology.

2019 ◽  
Vol 37 (27_suppl) ◽  
pp. 241-241
Author(s):  
Irbaz Bin Riaz ◽  
Rabbia Siddiqi ◽  
Noureen Asghar ◽  
Elizabeth Jane Cathcart-Rake ◽  
Vitaly Herasevich ◽  
...  
Keyword(s):  
Systematic Review ◽  
Systematic Reviews ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Quality Of Evidence ◽  
Principle Investigator

241 Background: In a rapidly moving field, such as cancer immunotherapy, where immune checkpoint inhibitors (ICIs) are used across 14 different tumor types, patients may receive suboptimal treatment or even be harmed if information on toxicity is not readily translated for use in clinical practice. Every single systematic review and meta-analysis which attempted to summarize toxicity of immune checkpoint inhibitors (ICIs) quickly became outdated. A living systematic review, which is defined as a systematic review that is continually updated to incorporate relevant new evidence as it becomes available, is necessary in this situation. Methods: The process of creating a living systematic review started with the creation of a comprehensive search designed by a librarian experienced in systematic reviews in collaboration with the study’s principle investigator. Search was constantly updated every 3 months and evidence is synthesized in a series of steps (microtasks) using a combination of human and augmented intelligence. A complete infrastructure is being developed and it includes automated cumulative meta-analysis and an online reporting platform which will constantly update information for clinicians and patients in a live manner. Results: We screened 6746 studies during Sep 2018-March 2019 and identified 6746 studies and we were able to successfully maintain up-to-date toxicity estimates for immune mediated adverse events over this period while maintaining the rigor of a conventional systematic review. Eventually, we will integrate the steps of LSR into one, user-friendly, semi-automated format which can independently provide accurate estimates and feed into and support a living guidelines platform through shared Application Programing Interface (APIs). Conclusions: LSRs are feasible, efficient, and when fully developed can reduce redundancy and waste in medical research, improve the quality of evidence, reduce human effort and support living and dynamic guidelines to facilitate truly informed shared decision making.

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