Background: The uncertainty in clinical practice arise from the need of physicians to make decisions on a limited ground of knowledges. Guidelines are supposed to facilitate clinical decisions in such circumstances. Sharing knowledges on natural history of diseases and clinical expertise allow to define and array of steps structured on a formal flow-chart. The node of algorithms identifies decisions to analyze. This paper presents a taxonomy of specific questions related to each decision nodes for management of unstable angina and assesses the level of evidence available for each question.
Material and method: A flow chart diagram display the conceptualized key nodes for clinical management of unstable angina. A set of specific question related to clinical exclusive circumstances, diagnostic approach, utility of diagnostic procedures, definition of prognosis and outcomes was raised for each decision node. From a systematic literature review the best available evidence was gathered. Each recommendation was linked to a level (A-C) of evidence, and to a body of consensus expert panel decisions.
Results: 34 decision nodes were identified, related with at least 1 question for appraisal of the best evidence. The solution to these questions yielded 40 recommendations scored by the strength of the evidence available. Five recommendations of diagnostic, 20 at prognostic and 15 at therapeutic step. The strength of evidence was A for 73% of recommendations at therapeutic step versus 40% at the two other steps.
Conclusions: A clinical complex problem can be displayed in a continuous process, to allow identification and appraisal of decisions at different clinical nodes. The work-up to achieve a conceptualization of a clinical problem is the preliminary step to develop clinical practice guidelines. Identification of decision nodes allows to manage uncertainty in a explicit way and make policy statement more acceptable by managers and physicians.