Maintaining a National Drug Dictionary sets both patient safety challenges and ontological difficulties to the National Release Centres. Pharmacists and ontologists have to cooperate to enable the integrated terminology management that is required to implement drug extensions. Snow Owl—a terminology management tool—has been extended with a profile for pharmacists for aided data entry utilizing Singapore extension SNOMED CT reference sets. An ontology generation process bridges between the raw pharmacy data and the ontological representation. The generated SNOMED CT concepts are fully defined and augmented with special description logic features to ensure that the classification returns valid results even in unusual use cases, like multi-ingredient products. The generated ontology includes all the semantics necessary to build intensional reference sets that support different clinical use cases like prescribing, dispensing or administration while the semantic query mechanisms that employ the ontological nature of SNOMED CT foster research and decision support on the Drug Dictionary. Please see our website http://b2i.sg for further information.

1. THE SINGAPORE
DRUG DICTIONARY
Developing and integrating a
national drug extension in
SNOMED CT
Orsolya Bali, Balázs Bánfai,
B2i Healthcare
10th October 2013

2. Agenda
¨ Introduction to the Singapore Drug
Dictionary and the Singapore SNOMED CT
Extension
¨ A profile for pharmacists to enter drug
definitions in Snow Owl
¨ Transforming pharmacy data into ontology
¨ Extensions to SNOMED CT
¨ Future plans
¨ Demo

3. The Singapore Drug Dictionary
• Support semantic
interoperability across
care settings and use
cases
• Utilize the Singapore
SNOMED CT Extension
• Supporting data
reference sets assist drug
definition
• Integrate detailed drug
definitions into SNOMED
CT’s ontological
representation

4. Built on top of the Snow Owl platform
¨ Snow Owl is a terminology authoring tool developed
by B2i Healthcare
¨ Besides SNOMED CT it supports various other
terminologies and code systems, value sets and
mappings
¨ Provides a collaborative authoring environment for
ontologists

5. Entering a source drug definition
¨ Form based editor
designed for
pharmacists
¨ Fields are restricted by
modeling rules
(available values are
defined by reference
sets and concept
attributes)
¨ Validation aids QA
¨ Preview provides a
glance at the concepts
to be generated

6. Structure of a source drug

7. Source drug editor demo
¨ Open RELENZA
¨ Review an ingredient
¨ Review a device
¨ Review a packaging
¨ Mention: mappings, formulations, manufactured
products
¨ Check Preview

8. The medication source data editor

9. Specifying the ingredient and strength
BOSS
automatically
calculated from
Ingredient
Units populated
from UOM refsets
, values are
normalized

10. Adding a device
Values are populated
from the Drug device
reference set

11. Creating a packaging
Value selection limited to
Drug container refset
Units are either
autocalculated by the
discrete dose form
unit relationship, or
can be selected from
a reference set

12. Map to external identifiers
Specify mapping to ATC
code, will generate map
reference set membership
for MP level concept

13. Preview of the generated ontology
View hierarchies
generated for different use
cases. Switch between
description types to use.

14. The ontology generation
¨ Transformation from
source data to fully
defined SNOMED CT
concepts
¨ Different types of
descriptions are
generated by pre-defined
algorithms
¨ Equivalent concepts are
filtered and merged by
the classifier
Amoxicillin
100 mg
Tablet
Amoxicillin
500 mg
Capsule
Amoxicillin
500 mg
Tablet

15. Core medication classes
© MOHH

16. SNOMED CT hierarchy demo
¨ Expand Pharmaceutical/Biological product
hierarchy
¨ Expand Singapore Medicinal Product hierarchy
¨ Set as root
¨ Expand hierarchies for MP level drug concepts,
expand Zanamivir to view hierarchies

17. The Singapore Medicinal Product
hierarchy
MP level concepts
are listed under
the root node

18. The Zanamivir hierarchy
Similar to the hierarchy
displayed in the preview,
but the reasoner merged the
equivalent concepts and
added the inherited
attributes

19. Classification issues
¨ Extended attribute types
¤ Float
¤ String
¤ Boolean
¨ Extended DL expressibility
¤ Disjointness of substances (?)
¤ Universal restriction
¤ Union groups

20. Maintaining the SDD extension within Snow Owl
¤ Namespace and module
¤ Reference sets
¤ Queries by attributes

21. Concept Editor demo
¨ Open an MPR level concept in an editor
¨ View universal restriction
¨ View concrete domain values representing the
strength
¨ View SNOMED CT properties section for module
and namespace
¨ Run pre-defined ESCG query to list all SG drugs
that are tablets

22. An SG drug in the SNOMED CT
concept editor 1.
Concept modeling rules are
partially implemented. Two
active ingredient
relationships are added for
proper classification – the
modifier is different.

23. An SG drug in the SNOMED CT
concept editor 2.
SDD module and namespace and concrete
domain elements (booleans) complete the
concept definition.

24. Attributes of an MPR concept
Strength is
specified for BOSS

25. Future plans
¨ Automatic regeneration of descriptions
¨ Withdrawing drugs – adjust the generated concepts
¨ Medication groupers
¨ Enhanced concept editors
¨ Query by concrete domain
¨ Online browser

26. THANK YOU!