Where should preappraised evidence summaries and guidelines place in a pyramid?

The letter by Kaufmann1 is quite reassuring as it demonstrates that policy researchers have intuitively and astutely questioned simple evidence hierarchies and were sceptical about using study design or study label as a surrogate for validity. This was the impetus for proposing our revised pyramid. The letter also reminds us that there are higher order scientific publications (guidelines and clinical synopses) that can also have variable levels of credibility. How can we place such highly synthesised and preappraised summaries in a pyramid? The pyramid suggested by Alper and Haynes2 includes such summaries but that pyramid conveys a hierarchy of ‘usefulness’ rather than of validity or credibility. In fact, many guidelines are poorly developed and not credible.3 We believe that these summaries can be appraised in a two-step approach (similar to a systematic review)4 and should not be placed in a pyramid....
Source: Evidence-Based Medicine - Category: Internal Medicine Authors: Tags: Letters Source Type: research