HyTime for Dummies

Author: Donna L. Hanlon (Bernickus, Dierker)

Abstract: Independent links (ilinks) nicely represent drug interactions in this example of how to apply HyTime to real-world problems.

Project Background

1. Base Genrx Product
• over 2000 generic drugs
• prescribing information similar to Physicians Desk Reference (PDR), but organized around the generic drug
• also includes drug class, brand, and cost information
• authored in SGML (see sample drug instance)
• output in book, CD, and web (see sample intranet page for Warfarin Sodium) media
• licensed in SGML to several value-added resellers
• used by MD Consult (new Web service for physicians)
2. Drug Master Plus (DMP) Interactions Database
• contains drug-to-drug, drug-to-diet, and drug-to-lab interactions
• currently sold as stand-alone application (see sample screens)
• acquired from Rapha Group Software, which still authors it and maintains stand-alone application
• was in btrieve format when first acquired; switched to topspeed soon thereafter

Problem: How to Integrate DMP with GenRx?

1. Needed neutral format developers (CD, web, MD Consult, etc.) could read
• Could partly read btrieve .dat files, but important text not readable
• Tried two conversion software utilities (e.g., Data Junction) to convert btrieve to ASCII, but couldn't get either to work (no data dictionary files)
2. Needed to associate DMP interaction classes with GenRx generic drugs (1:N)

Solution

1. Finally converted to ASCII via Rapha-developed report utility (see sample report format)
2. Converted into SGML to provide neutral format for CD and web developers and to integrate DMP with base GenRx product
3. drug-drug-intrx elements are HyTime (ISO/IEC 10744) ilinks, which have DMP interaction-class pairs as their anchor addresses
4. drug-drug-intrx anchadds are IDREFS keyed to interaction-class ids
5. interaction-class elements are HyTime namelocs containing one or more drug IDs from the GenRx instance (see example showing relationship between interaction-class and GenRx drug)
6. See trimmed-down DTD and sample instance
7. Link to GenRx allows not only traversal, but also use of more robust GenRx drug name index (see index excerpt)
8. HyTime supports future enhancements (e.g., classifying interactions by types such as "increases effects of"; decreases effects of"; or "causes death when combined with")
9. Web application already available (see Fred Dalrymple's presentation, "Implementing HyTime for Drug Interactions for Mosby Yearbook")
10. CD application under development now; will be available by 10/1/97

For More Information on HyTime

Robin Cover's The SGML Web Page provides one-stop shopping for SGML-related topics. You can access the entry for HyTime from the hub page, or by going directly to the spoke page for HyTime: ISO 10744 Hypermedia/Time-based Structuring Language.

About the author: Have worked in electronic publishing since 1990. Worked at the U.S. Army Aviation & Troop Command until 10/95. Now work for Mosby - Year Book, which has recently merged with Matthew Bender, another Times Mirror company. Education: MS in MIS, University of Missouri - St. Louis, 1995; BA in Math & Russian, Washington University, 1984.