XML

XML was developed to support what is known as self-describing data or semi-structured data—data that has an irregular structure not known in advance, and that can change frequently and without notice.

Thus, XML markup is ideal for representing both the gross document structure of documents and the fine structure of medical sentences. XML standards have emerged to represent medical documents.

HL7 document patient record architecture: an XML document architecture based on a shared information model. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2232652/)

XML and its impact on content and structure in electronic health care documents. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2232652/pdf/procamiasymp00004-0089.pdf)

XML representations can be enhanced through markup of individual medical terms using codes from a suitable dictionary72 and through integration of the results of natural language processing with the document structure.73 This feature enables semi-structured documents to be linked with an ontology of document types and sections, enabling subsequent processing.74

Storage and Retrieval

In our model, XML documents are managed by a database system that enables storage of XML in its native form and retrieval through the XQuery language (an emerging standard for XML queries). In exploring our model, we selected Tamino, 83 which can support very large collections of documents, but other systems with similar functionality could be used. By managing native XML in this manner, the space overhead of the markup is minimized. Designated elements can be indexed to make retrieval rapid. For example, all documents are indexed by medical record number to support browsing and authoring documents of a single patient.

NOTES

66. Suciu D. Proc Intern Conf Found Data Org, Kobe, Japan, November. Semistructured data and xml 1998.

67. Deutsch A, Fernandez M, Florescu D, Levy A, Maier D, Suciu D. Querying XML data Data Eng Bull 1999;22(3):10-18.