Considerations of complexity in rating certainty of evidence in systematic reviews: a primer on using the GRADE approach in global health

Public health interventions and health technologies are commonly described as 'complex', as they involve multiple interacting components and outcomes, and their effects are largely influenced by contextual interactions and system-level processes. Systematic reviewers and guideline developers evaluating the effects of these complex interventions and technologies report difficulties in using existing methods and frameworks, such as the Grading of...