Otolaryngology - Head and Neck Surgery, 2010

A systematic review is a transparent and unbiased review of available information. The published systematic review must report the details of the conduct of the review as one might report the details of a primary research project. A meta-analysis is a powerful and rigorous statistical approach to synthesize data from multiple studies, preferably obtained from a systematic review, in order to enlarge the sample size from smaller studies to test the original hypothesis and/or to generate new ones.

Clinical Infectious Diseases, 2013

The number of systematic reviews published in the peer-reviewed literature has increased dramatically in the last decade, and for good reason. They have become an essential resource for clinicians who want unbiased and current answers for their clinical questions; researchers and funders who want to identify the most critical evidence gaps for study; payers and administrators who want to make coverage, formulary, and purchasing decisions; and policymakers who want to develop quality measures and clinical guidelines. Targeted to beginners interested in conducting their own systematic reviews and users of systematic reviews looking for a brief introduction, this primer (1) highlights the differences between review types; (2) outlines the major steps in performing a systematic review; and (3) offers a set of resources to help authors perform and report valid and actionable systematic reviews.

Current Anaesthesia & Critical Care, 2005

Systematic reviews and meta-analyses are becoming more prevalent in the published literature and are routinely being used in the evidence-based approach to medicine. This article describes the process and methodology of conducting systematic reviews and meta-analyses and discusses the factors that affect the quality of the results and conclusions.

Blood, 2010

Systematic reviews and meta-analyses are being increasingly used to summarize medical literature and identify areas in which research is needed. Systematic reviews limit bias with the use of a reproducible scientific process to search the literature and evaluate the quality of the individual studies. If possible the results are statistically combined into a meta-analysis in which the data are weighted and pooled to produce an estimate of effect. This article aims to provide the reader with a practical overview of systematic review and meta-analysis methodology, with a focus on the process of performing a review and the related issues at each step.

European Journal of Epidemiology

To inform evidence-based practice in health care, guidelines and policies require accurate identification, collation, and integration of all available evidence in a comprehensive, meaningful, and time-efficient manner. Approaches to evidence synthesis such as carefully conducted systematic reviews and meta-analyses are essential tools to summarize specific topics. Unfortunately, not all systematic reviews are truly systematic, and their quality can vary substantially. Since well-conducted evidence synthesis typically involves a complex set of steps, we believe formulating a cohesive, step-by-step guide on how to conduct a systemic review and meta-analysis is essential. While most of the guidelines on systematic reviews focus on how to report or appraise systematic reviews, they lack guidance on how to synthesize evidence efficiently. To facilitate the design and development of evidence syntheses, we provide a clear and concise, 24-step guide on how to perform a systematic review and meta-analysis of observational studies and clinical trials. We describe each step, illustrate it with concrete examples, and provide relevant references for further guidance. The 24-step guide (1) simplifies the methodology of conducting a systematic review, (2) provides healthcare professionals and researchers with methodologically sound tools for conducting systematic reviews and meta-analyses, and (3) it can enhance the quality of existing evidence synthesis efforts. This guide will help its readers to better understand the complexity of the process, appraise the quality of published systematic reviews, and better comprehend (and use) evidence from medical literature.

2004

Systematic reviews and meta-analyses synthesize data from existing primary research, and well-conducted reviews offer clinicians a practical solution to the problem of staying current in their fields of interest. A whole generation of secondary journals, pre-appraised evidence libraries and periodically updated electronic texts are now available to clinicians. However, not all systematic reviews are of high quality, and it is important to be able to critically assess their validity and applicability. This article is an illustrated guide for conducting systematic reviews. A clear understanding of the process will provide clinicians with the tools to judiciously appraise reviews and interpret them. We hope that it will enable clinicians to conduct systematic reviews, generate high-quality evidence, and contribute to the evidence-based medicine movement.

Elsevier eBooks, 2023

Kidney International, 2009

Systematic reviews and meta-analyses are increasingly popular study designs in clinical research. A systematic review is a summary of the medical literature that uses explicit and reproducible methods for searching the literature and critical appraisal of individual studies; in contrast, a meta-analysis is a mathematical synthesis of the results of these individual studies. These study designs can be useful tools for summarizing the increasing amount of knowledge that is gained from scientific papers on a certain topic. In addition, combining individual studies in a metaanalysis increases statistical power, resulting in more precise effect estimates. Although the specific methodology of systematic reviews includes steps to minimize bias in all stages of the process, investigators should be aware of potential biases such as poor quality of included studies, heterogeneity between studies, and the presence of publication and outcome reporting bias. This paper explains how systematic reviews and meta-analyses should be performed and how to interpret and implement their results. In addition, we discuss when meta-analyses are useful and when they are not.

Principles and Practice of Clinical Research Journal, 2022

Nowadays, systematic literature reviews/meta-analyses of clinical trials are considered the best evidence in clinical research; thus, if performed appropriately, they can save resources by avoiding the development of unnecessary clinical trials. Nevertheless, to carry out a systematic literature review /meta-analysis, researchers must deeply understand its methodology. This narrative review aims to act as a learning tool for new researchers to perform systematic literature reviews/meta-analyses for categorical variables, addressing this matter in a step-by-step fashion using STATA 17. Readers must understand that the scope of this topic is much broader. Therefore, concepts such as meta-analysis for numerical outcomes or meta-analysis for survival analysis are not addressed. The authors hope that the information presented in this manuscript serves as pillars to enhance research worldwide, especially in places where formal research training is uncommon. If readers want to extend their knowledge regarding this subject, we recommend reading the "The Cochrane Handbook for Systematic Reviews of Interventions and the Center for Reviews and Dissemination" or the book "Finding What Works in Health Care: Standards for systematic reviews."

JAMA, 2014

Clinical decisions should be based on the totality of the best evidence and not the results of individual studies. When clinicians apply the results of a systematic review or meta-analysis to patient care, they should start by evaluating the credibility of the methods of the systematic review, ie, the extent to which these methods have likely protected against misleading results. Credibility depends on whether the review addressed a sensible clinical question; included an exhaustive literature search; demonstrated reproducibility of the selection and assessment of studies; and presented results in a useful manner. For reviews that are sufficiently credible, clinicians must decide on the degree of confidence in the estimates that the evidence warrants (quality of evidence). Confidence depends on the risk of bias in the body of evidence; the precision and consistency of the results; whether the results directly apply to the patient of interest; and the likelihood of reporting bias. Sh...