Drug quantity convention example

[MaximMoinat]

The description for drug quantity says:

However, in calculation examples I can find it is suggested that total dose is normally calculated as quantity * numerator_value for divisible products. For example:

• Drug Dose page
• Article on using drug strength

See also OHDSI/Themis#137.

[MaximMoinat]

To clarify: for a liquid/suspension/solution drug product, I expect the quantity to refer to the number of milliliters given, not the total dose in milligram. The dose can then be calculated from quantity and numerator_value in drug_strength table.

It would also help if there was an example in the drug dose page specifically for a solution clinical drug and a number of ml administered.

e.g.

4. Clinical Drug formulated as a concentration
   Example: The Clinical Drug is Acetaminophen 200 MG/ML Oral Suspension. 5 ml is administered (quantity 5).
   DRUG_STRENGTH The denominator_unit is mL. The denominator_value might be different from 1.
   DRUG_EXPOSURE The quantity refers to the amount administered, in the denominator_value.
   In the example: 5
   Ingredient dose= quantity x numerator_value [numerator_unit_concept_id]
   Acetaminophen dose = 5 x 200mg = 1000mg
   Daily dose = Acetaminophen dose/drug duration

[MelaniePhilofsky]

We also need the denominator value as per my example in this post. I have a question to the Vocab team about this field.

[MaximMoinat]

For awareness, there is now a thread on the Forums with new proposal for the CDM and conventions.
Drug Dose: Fixes required to allow a standardized calculation - Call for input