GRADE notes: How to use GRADE when there is “no” evidence? A case study of the expert evidence approach

OBJECTIVES: One essential requirement of trustworthy guidelines is that they should be based on systematic reviews of the best available evidence. The GRADE Working Group has provided guidance for evaluating the certainty of evidence based on several domains. However, for many clinical questions, published evidence may be limited, too indirect or simply not exist. In this brief report (GRADE notes), we describe our method of developing …