5.7. Reasons to upgrade studies

Author(s): 
Jo.Robays
Author(s): 
Joan.Vlayen

Observational studies are by default considered low level of evidence. However, the level of evidence can be upgraded for a number of reasons. an important general remark on this issue: only studies with no threats to validity (not downgraded for any reason) can be upgraded. RCT evidence can in principle be upgraded, but GRADE considers this as rare and exceptional.