Experience using a programmable rules engine to implement a complex medical protocol during order entry

WizOrder, Vanderbilt University Medical Center's (VUMC) clinician order entry system, is an excellent platform for delivering high-quality decision support to clinical end-users. A scripting language designed to make it easy for non-programmer domain experts to enter rules helps distribute the generation and maintenance of the knowledge-base necessary to drive effective decision support. Domain-experts have used this system to successfully implement relatively simple protocols. The VUMC Care Improvement Committee identified diagnosis of and treatment for suspected or confirmed deep venous thrombosis or pulmonary embolism as an area where decision-support could improve clinician compliance with established evidence-based protocols. The authors describe our experience with using our existing scripting system to implement decision support for a complex medical protocol.