Updating evidence-based clinical guidelines.

OBJECTIVES: To report on the updating of two evidence-based guidelines.
METHODS: Development of multi-disciplinary evidence-based guidelines within the North of England Evidence Based Guideline Development Programme.
RESULTS: The guideline updating groups were multi-disciplinary although the balance of disciplines was different from the original development groups; the convening of the updating groups allowed refinement of both the skills within the groups and the overall size of the groups. As both groups were starting with a previous version of the guideline, defining the scope of the guideline was more straightforward and faster than when developing the guideline de novo. The process of evidence identification for both guidelines was again by systematic review. Updating the guidelines influenced recommendations in two ways: new evidence required new recommendations; and supplementary evidence in an existing area allowed refinement of recommendations. Overall savings within the guideline updating process (compared with initial development) were modest. The major costs of both the initial guideline development and the updating process were staff costs, which were identical for the two processes.
CONCLUSIONS: There is little other experience to set alongside this paper. There is a need for further sharing of experiences and the development of explicit methods for informing decisions on when and how to update evidence-based guidelines.