Use of RxNorm and NDF-RT to normalize and

Use of RxNorm and NDF-RT to normalize
and characterize participant-reported
medications in an i2b2-based repository
Colette Blach, DTMI, Duke University
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I have no financial interests to disclose.
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MURDOCK Community Registry
50,000 subjects, >10K to date
• Patient reported medications, medical
history, lifestyle data
• Collect vital measurements and
biospecimens
• EHR data
• Lab tests/omics
• Annual follow up
• Consent for recontact
Cohort identification for follow-on studies
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L. Kristin Newby, MD, MHS
Rowena Dolor, MD, MHS
Collection of Medication
• Each participant was asked at enrollment and
then annually for a list of current medications
• 10,348 participants
• Average 2 years follow-up
• Free text entry of medications and reasons
for taking
• ~6 drugs reported per person each encounter
• 158,738 total medication entries
• 21,325 unique terms
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Medication standardization
“Prozac” “prozak” “fluoxetine”
“Sarafem”
Preferred Name: Fluoxetine ID: C0016365
CNS Meds
Antidepressants
SSRIs
Fluoxetine
MAOIs
Sertraline
Analgesics
Tricyclics
Opioid
Paroxetine
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Non-opioid
NSAIDs
RxNorm vs NDF-RT
• RxNorm (complex ontology)
• NDF-RT (hierarchy)
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Medication standardization
“Prozac” “prozak” “fluoxetine”
“Sarafem”
RxNorm API
Preferred Name: Fluoxetine ID: C0016365
CNS Meds
Antidepressants
SSRIs
Fluoxetine
MAOIs
Sertraline
Analgesics
Tricyclics
Opioid
Paroxetine
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Non-opioid
NSAIDs
Medication standardization
“Prozac” “prozak” “fluoxetine”
“Sarafem”
Preferred Name: Fluoxetine ID: C0016365
CNS Meds
Antidepressants
SSRIs
Fluoxetine
MAOIs
Sertraline
Tricyclics
Modified
NDF-RT
Analgesics
Opioid
Paroxetine
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Non-opioid
NSAIDs
What we had from MURDOCK participants
What mapped
directly to NDF-RT
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Medication component objectives
• Map free text drugs into coded terminology
• Modify NDF-RT with RxNorm medication
concepts (Brand names, ingredients and
sets)
• Translate coded terminology into leaves
on modified NDF-RT hierarchy
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Modified NDF-RT hierarchy
• Medication input was largely brand name or
ingredients only without dosage or route
• NDF-RT branches were extended with ingredients or
ingredient sets, then terminated with brand names.
• NDF-RT mapping was limited to Drug Products by VA
Class tree.
• Mapping from NDF-RT to RxNorm entirely algorithm
based.
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NDF-RT maps directly from lowest
class to [name-dose-route]
Antidepressants
SSRIs
MAOIs
Tricyclics
Sertraline 100 MG oral tablet
Sertraline 50 MG oral tablet
Etc.
Fluoxetine 60 MG oral tablet
Fluoxetine 10 MG oral capsule
Fluoxetine 4 MG/ML oral solution
Etc.
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Inserted drug name level- no dose, no route
(b/c that’s what we asked participants to give)
Antidepressants
SSRIs
Fluoxetine
Tricyclics
MAOIs
Sertraline
Paroxetine
Sertraline 100 MG oral tablet
Sertraline 50 MG oral tablet
Etc.
Fluoxetine 60 MG oral tablet
Fluoxetine 10 MG oral capsule
Fluoxetine 4 MG/ML oral solution
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Constructing modified hierarchy
• Reduce NDF-RT drug + route + dosage to drug-only concept
ACETAMINOPHEN 325MG TAB [VA Product]
 ACETAMINOPHEN
• Map brand names ingredients to the exact matching NDF-RT
Product Components or sets of Product Components. Brand names
with multiple ingredient are mapped first to avoid false partial
matches.
OXYCODONE HYDROCHLORIDE/ ACETAMINOPHEN
 PERCOCET
• For some NDF-RT branches, drug route is required for algorithm to
correctly identify tree branch.
EPINEPHRINE is used for both Ophthalmic and Respiratory
but Medihaler-Epi is not ophthalmic
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Problems encountered
•
Common ingredients could be mismapped onto branches if handled singly
and not as a only one of many concept components.
ACETAMINOPHEN and OXYCODONE HCL/ACETAMINOPHEN
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Multiple product components--problems mapping. Sometimes NDF-RT
concepts list a set of product components that overlap but don't identically
match RxNorm ingredient sets for what is visually the same concept.
OCUVITE LUTEIN vs OCUVITE LUTEIN CAP
NDF-RT
ASCORBIC ACID
RxNorm ASCORBIC ACID
COPPER
LUTEIN
VITAMIN E
ZINC
CUPROUS OXIDE
LUTEIN
VITAMIN E
ZINC OXIDE
MURDOCK
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Mapped Input  Modified NDF-RT
• Most mapped input linked directly to
modified NDR-RT
• Some input had dosage/route/timing,
requiring transformations.
Zolpidem Extended Release Tablet [Ambien]
• RxCUI unmapped to modified NDF-RT
tree are largely herbals, brand names,
BCPs
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Reason for Medication
• Registry collected both drug names and reason for drug
• Most common response: No Response
• Some inconsistency with the drug and participant-entered reason for the drug,
usually mis-mapping, secondary use or participant lack of understanding.
Input: BENAPRIL HCL
Reason: HIGH BLOOD PRESSURE
Mapped to: BENADRYL (score = 50) (probably BENAZEPRIL?)
Input: ROSUVASTATIN, CRESTOR
Reason: BONE
Mapped to: CRESTOR
MURDOCK
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Reason for Medication
• Some of the participants were taking prescription drugs for a disorder but
responded in medical history that they were never diagnosed with the
disorder.
159 Participants
Meds: CITALAPRAM, LEXAPRO, CELEXA,
SERTRALINE, FLUOXETINE and others
Reason: Depression
Medical History Depression: No
• Standardized entry of medication reasons would enhance medication data.
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Researcher Queries
Although mapping was highly usable, testing identified
limitations.
• Tool is not a substitute for researcher’s knowledge of
medications.
• Researchers cannot rely exclusively on medication category
to identify cohort participants having a specific condition.
• Fewer drugs exposed by only using “Drug Products by VA
Class”.
• Ideal implementation is based on specific use case.
MURDOCK
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Future Plans
• Explore DrOn for more precise mapping?
• Consider leverage reason taking in coding drug
information.
• Move to electronic input and drug dropdowns.
MURDOCK
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Acknowledgements
• Lee Peters- NLM
• Mike Lincoln- VA
• John Carter- Apelon
Co-Authors:
• Guilherme Del Fiol
• Chandel Dundee
• Julie Frund
• Rachel Richesson
• Michelle Smerek
• Anita Walden
• Jessica D.
Tenenbaum
Funding from David H.
Murdock and NIH
UL1RR024128
• Russ Waitman
• Nathan Graham
• Matvey Palchuck
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