A model of ambiguity and vagueness in clinical practice guideline recommendations.

Ambiguity and vagueness in clinical practice guidelines reduce the likelihood of clinician adherence. They lead to inconsistent interpretation and, in turn, to inappropriate practice variation and medical errors. Resolving ambiguity and vagueness is an essential step in the computerized implementation of clinical practice guidelines. Successful resolution of ambiguity and vagueness requires an understanding of their characteristics, yet ambiguity and vagueness have not been differentiated, classified and described in medical context. In this paper, we propose a tri-axial model to describe ambiguity and vagueness in clinical practice guidelines: differentiation of true ambiguity from vagueness, classification of ambiguity and vagueness, intentionality and components involved. Our goals in introducing this model are: (a) to provide guidance to guideline authors to enable them to reduce inadvertent use of ambiguous or vague language, (b) to improve transparency when vague language is used deliberately and (c) to create a framework for the development of tools to apply the model during authoring and implementation of clinical practice guidelines.