SGML, XML and the Kona Architecture

What is SGML? -- An Acronym

Standard - International standard ISO-8879

Generalized - Not tied to a single machine, platform or system

Markup - Describes information about the content of a document

Language - Definitions of the structure of the document contains can be written

Sample SGML Document

<!DOCTYPE REPORT PUBLIC "-//KonaExample//DTD Prescription 970926//EN" [<!DOCTYPE REPORT PUBLIC "-//KonaExample//DTD Prescription 970926//EN" [

]>]>

<PRESCRIPTION>Amoxicillin

<FORM><FORM>250 mg. capsule</FORM><DISPENSE>30</DISPENSE><DOSAGE>1 cap(s) </DOSAGE><INSTRUCTIONS>3 times daily until gone </INSTRUCTIONS> <REFILL>0</REFILL><SUBSTITUTE>may substitute</SUBSTITUTE><NUMBER NOTYPE="DEA">AB1234567</NUMBER>

</PRESCRIPTION>

What SGML Provides

a list of elements which appear in a document

a specification of the order and frequency in which these elements appear in the document (DTD)

a verification that the marked up document conforms to the specification (parsers or validations)

Elements

Elements are delimited with start tags and end tags

Start tag Content End tag

<MEDNAME > Tylenol </MEDNAME>

One element

Attribute Syntax

Attributes immediately are specified after the element they are associated with

Start tag Attribute Content End tag

<MEDNAME Generic = “Acetaminophen”>Tylenol </MEDNAME>

One element with one attribute

What’s a DTD ?

Document Type DefinitionDescribes the structure of the

document The names of allowable elements the content of each element type the structure of the document including

the order in which elements must appearhow often elements can appear

the properties of the elements (attributes)

What is the Difference between HTML and SGML?

HyperText Markup Language (HTML)An application of SGMLA DTD for authoring documents to be

distributed via the World Wide WebFormats documents for viewing on a

computer screen

Why not use HTML?

Does not offer a rich tag setNo mechanism to structure

documents in a clinical mannerInstable as a standardDelivery format not a collection

technologyLoose document type

What is XML?

eXtensible Markup Language (XML)XML = SGML with a few exceptions:

A DTD is not required Provides stylesheets for presentation in

a web browser (XSL) Some SGML syntax is not supported Designed for simple processing of

diverse types of documents and data

The Role of XML

When HTML does not meet the needsWhen collection of information is

requiredWhen information resources are of long

term valueWhen there are complex relationships

between information resources (links)

XML Example

<?XML version="1.0" ?><?XML version="1.0" ?>

<PRESCRIPTION><PRESCRIPTION>

<MEDNAME MED="Amoxil"><MEDNAME MED="Amoxil"> Prescribed medication: Amoxil</MEDNAME></MEDNAME>

<FORM TYPE="capsule"><FORM TYPE="capsule"> Form: capsule </FORM></FORM>

<DOSAGE AMOUNT="25 mg"><DOSAGE AMOUNT="25 mg"> Dosage: 25 mg</DOSAGE></DOSAGE>

<RXINSTRUCTIONS FREQUENCY="daily"><RXINSTRUCTIONS FREQUENCY="daily"> daily </RXINSTRUCTIONS></RXINSTRUCTIONS>

</PRESCRIPTION></PRESCRIPTION>

What is the KONA Proposal?

ProposalArchitecture that allows for varying levels

of complexity in clinical documentsInterface that is a mediator between two

applications or systemsExchange mechanism from a document

centered perspective with varying levels of requirements

The Kona Architecture

Multi-layered schema consisting of three layersA basic, abstract layer to exchange

narrative documents (ProseDoc)A layer that provides simple

classification (ClinicalContent)A layer that requires greater clincical

semantics

The KONA Architecture

Moving Boxes

Content: shoesMy Label:

Master Bedroom Closet: slippers, running shoes, hiking boots

Foreman Mover’s Label: First Upstairs Right Room

Actual Mover’s Label: Upstairs

A Transformation

<PRESCRIPTION>

<MEDNAME MED="Amoxil">

Prescribed medication: Amoxil</MEDNAME>

APPLICATION KONA

Architectural Forms specify how tags are changed:

<PLAN CC.CLIENT.ETN="PRESCRIPTION">

<MENTION DOMAIN="Kona Example" NORMALIZED.CONTENT="Amoxil" CC.CLIENT.ETN="MEDNAME"> Prescribed medication: Amoxil

</MENTION>

Transform <PRESCRIPTION> to <PLAN>

SGML Architectures

SGML architectures facilitate exchange between SGML documents & differing DTDS Organizations will most likely create

their own DTDs to best meet their needs Semantics vary by granularity,

localization, and specialization

Kona Design Assumptions

Kona builds on HL7; 2.3 used for proposal

Documents contain narrative text and data (codes)

Not all clinical documents require the same degree of codes or markup

Flexible exchange: an oxymoron?

Central dilemma of all information exchange standards:local diversity, responsive to changeglobal rigidity, resistive to change

How to provide extensible, flexible framework for information, yet retain the ability to exchange it freely?

Flexible exchange: Kona methodology

Provide central information model : RIM + Meta DTDs

Provide context for narrative textDevelopment not required for

mapping from local/specialized model to exchange model