I’m seeing some differences between what I’m getting in FHIR messages from synthea v. codes in OMOP for UCUM vocabulary. Most of these seem to be around punctuation for lack of a better word (things like _, {, }, [, ], /,. etc.). Examples include (concept_id/FHIR/OMOP):
8876, mmHg, mm[Hg]
44777566, {score}, [score]
9117, mL/min/{1.73_m2}, mL/min/1.73.m2
These codes were specifically found in this resource:
https://syntheticmass.mitre.org/v1/fhir/Patient/6f7acde5-db81-4361-82cf-886893a3280c/$everything
I’m using this version of the OMOP vocabulary:
UCUM
Unified Code for Units of Measure (Regenstrief Institute)
http://aurora.regenstrief.org/~ucum/ucum.html#section-Alphabetic-Index
Version 1.8.2
44819107
If you're seeing mmHg as a UCUM code in FHIR synthea data, that's an error. Similarly, "{score}" is correct, while "[score]" is not. Both mL/min/1.73.m2 and ml/min/{1.73_m2} are valid units, though they're not equivalent.
I would recommend reporting the issues to Synthea.