Of studies, syntheses, synopses, summaries, and systems: the “5S” evolution of information services for evidence-based healthcare decisions

A "4S" model for the organisation of evidence-based information services, proposed several years ago, 1 begins with original studies at the foundation; syntheses (that is, systematic reviews, such as Cochrane Reviews) at the next level up; then synopses (very brief descriptions of original articles and reviews, such as those that appear in the evidence-based journals); and the most evolved services, systems (such as computerised decision support systems that link individual patient characteristics to pertinent evidence) at the top. If a current topic summary exists, it would summarise the relevant synopses, syntheses, or studies about several aspects of a health condition. [...]a current summary "trumps" an individual synopsis, synthesis, or study or a collection of these.