Quality appraisal includes the GRADE approach. GRADE provides a framework for “rating the quality of a body of evidence in systematic reviews and other evidence syntheses. GRADE offers a transparent and structured process for developing and presenting evidence summaries.”1
Why is GRADE important? Systematic reviews are used by decision makers to make recommendations for clinical actions, best practice, or practice guidelines. Systematic reviews “provide essential, but not sufficient information for making well informed decisions.” 2 People who use reviews draw conclusions about the quality of evidence provided by the authors. In systematic reviews, “the quality of evidence reflects the extent of confidence that an estimate of effect is correct.”3 GRADE provides “a systematic and transparent approach for rating the certainty of evidence in systematic reviews.”4
“In the GRADE approach, randomized controlled trials (RCTs) start as high-quality evidence and observational studies as low-quality evidence supporting estimates of intervention effects. Five factors may lead to rating down the quality of evidence and three factors may lead to rating up.”5 Systematic review authors “use this approach to rate the quality of evidence for each outcome across studies.”5 The endpoint for systematic reviews “is a summary of the evidence – the quality rating for each outcome and the estimate of effect.”5
After Guyatt G, Oxman AD, Akl EA, et al.5
1. Schünemann H, Brożek J, Guyatt G, Oxman AD. The GRADE handbook. The Cochrane Collaboration. http://gdt.guidelinedevelopment.org/central_prod/_design/client/handbook/handbook.html
2. GRADE. GRADE. Accessed August 3, 2021. https://www.gradeworkinggroup.org/#
3. Guyatt GH, Oxman AD, Kunz R, et al. What is "quality of evidence" and why is it important to clinicians? BMJ (Clinical research ed). 2008;336(7651):995-8.
4. Granholm A, Alhazzani W, Moller MH. Use of the GRADE approach in systematic reviews and guidelines. British journal of anaesthesia. 2019;123(5):554-559. Comment on: Br J Anaesth. 2019 Oct;123(4):e479-e480; PMID: 31301760.
5. Guyatt G, Oxman AD, Akl EA, et al. GRADE guidelines: 1. Introduction-GRADE evidence profiles and summary of findings tables. Journal of clinical epidemiology. 2011;64(4):383-94. Comment in: J Clin Epidemiol. 2015 May;68(5):597-600; PMID: 25660962.