PREOP: development of an evidence-based expert system to assist with preoperative assessments.

PREOP is a prototype expert system that is designed to provide physicians with evidence-based recommendations concerning the assessment and care of patients with comorbid medical problems who are about to undergo surgery. The knowledgebase for this system is currently undergoing transition from the conventional advice of medical experts, which is variably related to evidence published in the medical literature, to a more formal approach in which the best available evidence is used for each recommendation and the quality of the evidence made apparent to the user. This work seeks to address important questions concerning improvement of the information contained in expert knowledgebases, namely, how to find and recognize new evidence when it is published, how to assess the quality of evidence in a uniform and efficient fashion, how to replace evidence in the knowledgebase efficiently when it has been superseded by higher quality evidence, and how to represent evidence in a manner that is most valuable for the user.