"Inhalation" not a "Route of administration value" in SNOMED

[abedtashh]

After looked up "Inhalation" (45956874) in SNOMED on UMLS, I noticed the concept is not a "Route" but a "unit of product usage". We have it right now under "Route of administration value" (4106215) concept which seems incorrect according to UMLS. I also could not find any concept with code 18679011000001101 in SNOMED.

If you look up "Inhalation" in UMLS, there are other terminologies like NCI denoting "inhalation" as a route of administration, but the reference in OMOP vocabulary is SNOMED not NCI.

One probable cause might be that "Inhalation" is a synonym of a "Route of administration value" child, but I could not find one.

The closest concept to what we know as inhalation route is "Intrapulmonary route" (4169270), which NCI defines as "Administration of a substance in the form of a gas, aerosol, or fine powder via the respiratory tract, usually by oral or nasal inhalation, for local or systemic effect."

Should we remove "Inhalation" from "Route" domain?

[cgreich]

@abedtashh:

Inhalation as a unit is called "actuation" in RxNorm lingo. Like a puff of an inhaler. So, if it really is used as a unit then just use that.

[abedtashh]

@cgreich Well, RxNorm is using "Actuation" as a unit of volume (like ML, MG) but it is actually the "unit of presentation" like Ampule or Tablet in UMLS.

That's fine if the definitions of "drug strength units" are different. The question is whether to keep "Inhalation" in "Route" domain because there is no such "Inhalation" (or "Actuation") route in SNOMED (all routes are adopted from SNOMED). Inhalation is a "unit of product usage" but in Route domain right now which is not correct. Needs to be moved to "Observation" domain with class_id=Qualifier Value.

The closest route you can find in OMOP vocab for an inhaler is "Intrapulmonary route" (4169270), of course with "Inhalation" unit of dose.

[dimshitc]

@abedtashh , thanks for noticing this. We take the descendants of "Route of administration value" (4106215) to define the Route concept set. "Inhalation" (45956874) is a "Route of administration value" (4106215) descendant in UK-SNOMED extension. look: http://ontoserver.csiro.au/shrimp/?concept=18679011000001101&system=http://snomed.info/sct&versionId=http://snomed.info/sct/999000031000000106/version/20180321 In the OHDSI vocabulary SNOMED vocabulary is a mix of SNOMED international and UK SNOMED. So technically "Inhalation" (45956874) has domain_id = 'Route' is right

[abedtashh]

@dimshitc Thanks. That's true. "Inhalation" is a route of admin in SNOMED-UK. So, if Route domain is a mixture of concepts from multiple terminology versions, does it make sense to flag only one of the "synonyms" as "Standard" and relate others to the standard through "Maps to" relationships? Because vocabulary users may use them interchangeably that may cause some inconsistencies across CDMs.

Suggestion: The two concepts of "Inhalation" and "Intrapulmonary" are almost the same. "Intrapulmonary" can be tagged as "C" (classification).

[dimshitc]

Just wondering: can inhalation be non-pulmonary route, i.e. the target organ is bronchus or trachea?

[aostropolets]

Actually, most of inhalants target bronchi; inhalation is more generic name than intra-pulmonary and in the same time more convenient

[dimshitc]

Thanks, @aostropolets so it means that we need to leave our routes as is @abedtashh , what do you think?

[abedtashh]

@aostropolets @dimshitc Inhalers and nebulizers are used to deliver drugs in forms of powder, liquid, gas, aerosol, or emulsion to lower respiratory tract including bronchi and lungs. Some act locally like bronchodilators for treating asthma but some systemically like inhalable insulin. Basically "Intrapulmonary" and "Inhalation" are technically synonyms as both indicate "delivering drugs by inhaling air (or breathing) into lungs and bronchi", so both can be used for e.g., "salmeterol inhaler" products that may make confusions/inconsistencies across CDMs. Since "Intrapulmonary" route has the "Intrabronchial" child in SNOMED hierarchy meaning "administration of a drug within bronchi", I suggest to either:

• Pick "Inhalation" as the Standard concept for "administration of drugs in forms of powder, liquid, gas, aerosol, or emulsion to lower respiratory tract" AND put "Intrapulmonary" as a Classification concept.
• Or, make "Inhalation" non-standard AND keep "Intrapulmonary" as the only Standard route concept for such dose forms.

[aostropolets]

The first option sounds perfectly fine. You are absolutely correct in your explanation, I favor “Inhalation” only in terms of a name being wildely known

[abedtashh]

@aostropolets @dimshitc Great! I think the first option is the a good solution as well.

[m-khitrun]

Hello,

Just to let you know, the concept Inhalation was invalidated as it belongs to the retired SNOMED UK Drug Extension Module. It was mapped to the Respiratory tract SNOMED route.

Regards, Masha.