Is the Guideline Process Replicable and, if Not, What Does This Mean?

Increasingly, guidelines determine how medical care will be provided. However there has been limited study of the determinants of the reliability of the guideline process. Guidelines translate evidence into recommendations. If only the evidence determines the recommendations, given the same evidence, different panels of experts should make the same recommendations. That is, the process should be replicable, an essential characteristic of a valid scientific process. The multiple recent cholesterol guidelines, which have considered the same evidence, offer an opportunity to examine guidelines from this perspective. Considerable discordance among the guideline recommendations is evident pointing to an important role for the participants, in addition to the evidence, in the development of guideline recommendations. Guideline recommendations, therefore, appear to be based on both evidence and expert opinion.