Evidence-Based Decision-Making 1: Critical Appraisal

Abstract

This chapter provides an introduction to the concept of Evidence-based Medicine (EBM) including its history, rooted in Canada and its important role in modern medicine. The chapter introduces EBM and explains the process of conducting EBM . The chapter starts with a description of the traditional hierarchy of evidence that exists in research with reference to the critical appraisal tools often used to assess the quality or credibility of individual studies. It includes a section on assessing risk of bias in randomized clinical trials and non-randomized studies and guidelines for reporting study findings now fully captured in the EQUATOR Network. In addition, a section on GRADE (Grades of Recommendation Assessment, Development and Evaluation) and the process used to determine the quality of evidence when guiding clinical decisions or developing clinical practice guidelines is included. In response to the substantial number of research syntheses being published, AMSTAR2, a tool used to critically appraise the quality and reporting of systematic reviews is described. The main focus of the chapter remains on how to critically appraise the medical literature, as one step in the EBM process. However, this process also includes an assessment of study bias and an understanding of reporting guidelines. At its basic level, critical appraisal requires an understanding of the strengths and weaknesses of study design and how these in turn impact the validity and applicability of research findings. Strong critical appraisal skills are critical to evidence-based decision-making .

Keywords: Bias; Critical appraisal; Evidence-based medicine; Reporting guidelines; Study design.