OHDSI Home | Forums | Wiki | Github

Units of Measure to Add

(Meghan Pettine) #1

While mapping units of measure to their standards, I have found a short list that appear to be in the UCUM but do not have a standard mapping in the OMOP Vocabulary. Is it possible to have these added? Or if there is a way to map these that I am not understanding please advise. Thank you!

{copies} – Copies

U/dL – Enzyme unit per deciliter

U/mL – Enzyme unit per milliliter

mL/(kg.min) – Milliliter per kilogram per minute

nmol/h/mg{protein} – Nanomole per hour per milligram of protein

pmol/h/mg{protein} – Picomole per hour per milligram of protein

(Anna Ostropolets) #2

Seems that some of your units are substance-agnostic, so I’d suggest the following:

{copies} – Copies can be left w/o unit especially if LOINC test already gives you the unit in its name
U/dL – Enzyme unit per deciliter 44777568 unit per deciliter
U/mL – Enzyme unit per milliliter 8763 unit per milliliter

For nmol/h/mg{protein}, pmol/h/mg{protein} and mL/(kg.min) examples of the substances may be helpful. For example, protein may be hemoglobin and then pmol/h/mg{protein} can be mapped to picomole per hour and milligram of hemoglobin or converted to nanomole per hour and milligram or else.

(Meghan Pettine) #3

Thanks for the guidance @aostropolets!

(Alexander Davydov) #4

I know there were some limitations in analytical methods (value_as_number thing), so that unit to be always specified.
Don’t we need a dummy unit for such cases? E.g., piece/item/each?

But agree, copies without the denominator (volume of sample) don’t make a lot of sense.

(Meghan Pettine) #5

@aostropolets @Alexdavv

I want to circle back to this – let me provide more context. I am working on mapping values that are on a form, which is why this is substance agnostic as Anna mentioned and also why I would like to do a one to one map rather than calculating by substance. For example on the form there is copies/L and copies/mL, however there is also a box that can be checked just for copies in case there is no denominator information. The form has an open text line to fill in other information and we are trying to take what we can and automate that process, hence the reason this is probably coming across a request that does not make sense. I need to worry about mapping just unit information even if that information standing alone would not normally serve a purpose, it does in this scenario.