Storage Model for CDA Documents

The Health Level 7 Clinic Document Architecture (CDA) is an XML-based document markup standard that specifies the hierarchical structure and semantics of “clinical documents” for the purpose of information exchange. In this research, issues arising with the design and implementation of a DB to support efficient retrieval from CDA documents and data mining for statistical analysis purposes are explored. Both an object-relational approach and a traditional relational approach were explored and compared in terms of design, implementation issues and efficiency. Although the object-relational approach results in a simpler design, implementation is more complicated as object methods must be programmed. In the relational design, queries were more complex to express than in the object-oriented design, but more efficient to execute. It was concluded that the DB design should use standard relational tables while using objects only when required for specialized processing, such as processing of graphs or scans.