Generating Computable Phenotype Intersection Metadata Using the Phenoflow Library
2. Generating Computable Phenotype
Intersection Metadata Using the Phenoflow
Library
Toward Implementation: Addressing Real-World Deployments
S25
Martin Chapman, Vasa Curcin
King’s College London
Luke V. Rasmussen,
Jennifer A. Pacheco
Northwestern University
Laura K. Wiley
WashU Medicine
3. DISCLOSURE OF CONFLICTS OF INTEREST
I have not had any relationships with ACCME-defined ineligible companies within
the past 24 months.
6. Phenotype definition multiplicity
This is a good thing (mostly)…
• It is not desirable (or feasible) to have a single computable phenotype for
every condition. Different use cases necessitate different logic.
But…
• We need to understand which use cases are already supported, to facilitate
reuse. In other words, we need to understand what is unique about each
phenotype. This can then be stored as metadata.
7. Phenotype intersection
To understand what is unique about each
phenotype (and thus which use cases it best
supports), we can first do the opposite and
understand how two phenotypes for the
same condition intersect.
We can aim to do this automatically and
therefore at scale.
8. Barriers to automated intersection analysis
1. Identifying when two computable phenotypes target the same disease or
condition in the first place.
• e.g. ‘T2DM Implementation’ vs. ‘Type 2 Diabetes Mellitus’ (PheKB)
2. Comparing different forms of computable phenotypes
• e.g. codelists vs. Natural Language Processing (NLP)
9. Methods: Identifying same disease/condition
1. Levenshtein distance to identify text similarity.
2. HDR UK API calls to identify phenotypes that target the
same condition but lack text similarity using common
keywords.
3. Large Language Model (LLM) (Llama 3.1) to validate the
additional phenotypes returned in 2. (Not all 161 definitions
are actually for diabetes).
11. Results: Intersection – Condition groups
1171 definitions loaded into the Phenoflow library.
137 condition groups (conditions with two or more phenotypes). PPV 95%.
574 definitions exist as a part of a group (49%).
Good insight into the extent of the definition multiplicity phenomenon.
12. Results: Intersection – Steps
Trend: Across the 10 largest condition
groups, the average number of steps in
common between pairs of definitions
relative to the average number of
steps in the group is low.
While definition multiplicty exists,
definitions still have a considerable
number of unique steps.
13. Results: LLM impact
We observed our LLM:
• Identifying false positives (e.g. matches between phenotypes for different
types of heart failure).
• Identifying false negatives (e.g. phenotype names that do not include the
condition but still aim to identify the condition via the presence of
medications).
14. Summary and Future work
The use of Phenoflow has allowed us to compare definitions to understand more
about definition multiplicity (extensive) and intersection (limited).
Integrating an LLM increases the reliability of this process.
Unique steps will soon be added to Phenoflow as metadata to support reuse.
To complement definition intersection insight (horizontal), definition
subsumption (vertical) will be explored next.