Structuring healthcare knowledge bases: an analysis of explicit and implicit structures in Arden Syntax and an XML schema representation of Arden Syntax.

The Arden Syntax for Medical Logic Modules (MLMs) is an ANSI and ISO recognized standard language for representing clinical knowledge bases. We analyzed the explicit and implicit structures in Arden Syntax MLMs and developed an information model represented as an XML schema. While the explicit structures were easily represented as XML, implicit structures require further explicit definition. In any future representation format, explicit structuring must be balanced with expressiveness and usability.