Aims: With the increase in the number of systematic reviews available, a logical next step to
provide decision makers in healthcare with the evidence they require has been the conduct
of reviews of existing systematic reviews. Syntheses of existing systematic reviews are
referred to by many different names, one of which is an umbrella review. An umbrella review
allows the findings of reviews relevant to a review question to be compared and contrasted.
An umbrella review's most characteristic feature is that this type of evidence synthesis only�…