Medical Standards

The increasing role of IT in the medical industry requires sharing of data between different medical systems and institutions. CDISC (Clinical Data Interchange Standards Consortium), founded in 1997, is responsible for developing and standardizing data-sharing protocols for the exchange of scientific content. CDISC’s corporate members include Glaxo SmithKline, IBM, Aventis, etc. 

CDSIC wants to create a standardized end-to-end data flow of clinical data (from source to an operational database) by using SDM (Submission Data Modeling) and ODM (Operational Data Modeling). ODM deals with the operational part, specifically data acquisition, interchange and archiving. SDM deals with standard metadata models to support data flow between peers–regulatory authorities, medical institutions, operational databases, etc. The data models are based on
XML.

An ODM XML file includes, in XML terminology, both ‘content’ (trial data) and ‘metadata’ (XML tags that define the meaning of the embedded values). The permitted syntax and structure of an ODM XML is as per the CDISC’s ODM
DTD.

Below are two examples of sections of a file in ODM format.

This illustrates how trial-specific metadata is defined. It corresponds to a template, using which data values can be added later (see second example). The aspect being defined is the concept of an item group, or a group of logically-associated clinical data items. In the particular example shown, the item group being defined corresponds to the trials demographic data (DEMOG) and consists of items for the site-patient-ID, initials, sex, date of birth, sponsor patient ID, weight in pounds, and weight in kilograms.

P001

AMH

F

16-Jul-1947

B00-2136-001

150.00


ItemID=”WEIGHT_KG”/>68.18 

The above shows how clinical data may be represented (like demographic metadata defined above). You’ll find more details at
www.cdisc.org. 

Ankit Khare