Implementing Ontology-Driven Care Pathways Using UML Activity Diagrams

Care pathways provide a formal representation of clinical guidelines, evidence-based best practice or care provider protocols. Executable care pathways can be used in an Electronic Health Record system to drive the process of care in a similar way to a standard business workflow. Care pathways are generally more complex than business workflows and this has led to the development of various domain-specific languages for pathway modeling, including GLIF and PROforma, as well as the application of visual approaches using BPMN, UML and BPM+ Health. The open source cityEHR health record system represents care pathways as HL7 CDA document templates which are generated from ontology models of the underlying clinical domain, built using an ontology architecture based on the ISO 13606 Reference Model. This paper describes how clinicians can specify pathways as UML Activity Diagrams that are then transformed into the ontology models and HL7 CDA representations that drive the executable pathways in cityEHR. It is shown that the simple application of UML Activity Diagrams is sufficient to support executable care pathways, specified as ontology models and represented as HL7 CDA in the patient record.