Using scenarios in chronic disease management guidelines for primary care.

The Prodigy system is a guideline-based decision-support system designed to assist general practitioners in England choose the appropriate therapeutic action for their patients. As part of the system, we developed a novel model for encoding clinical guidelines for managing patients with chronic diseases such as asthma and hypertension. The model structures a guideline as a set of choices to be made by the clinician. It models patient scenarios which drive decision making and are used to synchronize the management of a patient with guideline recommendations. The model is robust with respect to available input data and leaves the control of decision-making to the clinician. We have built execution engines to verify the computability of the model. We intend to test the model integrated in up to 200 live systems from at least four system vendors in English General practice.