To be clear, we’re talking about restricting routes of administration based on the dosage form, not the dosage units. Dosage form is the form in which the medication is manufactured (tablet, capsule, syringe, etc.) and is expected to be part of the definition of the drug. Dosage unit the the units the provider uses to express the dose, which can be expressed in the dosage form (1 tablet) or often a mass-based (mg, microgram) unit. For example, many breathing treatments have a dosage form of “inhaler” but nobody is doing to say “Take 1 inhaler daily”; rather, the dose units is typically in “puff(s)” or “inhalation(s)”.
Concept classes are effectively concept sets that are universally useful that we want to program against. For example, we could define Tests, Drugs, and Diagnoses as concept sets too, but, since every implementation needs these categories of concepts and we want to be able to program directly against these notions. And, as @ibacher mentioned, it’s cleaner to simply classify these as what they are – dosage forms – instead of classifying them as “Misc” concepts that are added to a concept set.
I was picturing CIEL would have concepts with classes of “Drug Form” and “Drug Route” we’d use those concepts to populate a single many-to-many table like:
| Dosage Form | Route |
|---|---|
| tablet | by mouth |
| tablet | g-tube |
| tablet | vaginal |
| tablet | rectal |
| capsule | by mouth |
| sublingual tablet | sublingual |
| … | … |
When a drug is ordered, only the routes matched to the drug’s dosage form would be shown as route options.