PRODIGY is a guideline-based decision support system in use by a large number of GPs in the UK.

PRODIGY I and PRODIGY II were implemented as extensions to proprietary UK electronic patient record systems. The PRODIGY system includes a guideline model, which in PRODIGY II was used to implement guidelines for the management of acute diseases.

PRODIGY 3 model

The PRODIGY 3 model was created to model guidelines for the management of chronic diseases, such as asthma, hypertension and angina, in primary care. Essentially, it supports guideline modelling a series of decisions that a GP may have to make in different patient encounters. The model enables a guideline to be organised as a network of patient scenarios, management decisions and action step which produce further scenarios. Scenarios are patient states defined by the patient's condition and current treatment. Scenarios are associated with:

• A consultation template that describes the best-practice workup for a patient in that scenario;
• A choice between alternative courses of action.

The PRODIGY3 decision model uses rule-in and rule-out conditions associated with each available alternative to determine the preferred course of action.

The management over time of a patient according to a guideline specification can be viewed as the traversal of a number of selected scenarios and associated actions and further decision points along a single path. Sequencing of actions is achieved by defined followed-by relations.