Stream: implementers
Topic: Quantity qualifier
Jose Costa Teixeira (Jan 19 2021 at 12:35):
We need to express a quantity qualifier such as "ad 100 ml" - meaning "up to 100 ml" .
in this case, "up to" is not an interval for free choice. It means precisely: "enough quantity so that the total volume is 100 ml
Has anyone encountered this?
Lin Zhang (Jan 19 2021 at 13:25):
<=?
Lin Zhang (Jan 19 2021 at 13:28):
OR
Lin Zhang (Jan 19 2021 at 13:35):
Add water/liquid to get a total vol of 100 ml?
Jose Costa Teixeira (Jan 19 2021 at 14:13):
the idea is "add ingredient X to get a total volume of 100 ml".
Jose Costa Teixeira (Jan 19 2021 at 14:13):
So <= doesn't work
Jose Costa Teixeira (Jan 19 2021 at 14:14):
this is normal in pharmacy / magistral preparations, but I don't see it in FHIR. the group I was discussing with today added an extension
Rik Smithies (Jan 19 2021 at 14:48):
Is this the same as or similar to "sufficient quantity?
@Alexander Zautke @Jose Costa Teixeira
Could this be related to this? https://chat.fhir.org/#narrow/stream/179166-implementers/topic/Quantity.20Comparators.20for.20.22Approximately.22
Would a standard extension be helpful?
Other possibly related concepts: "[quantity is ] equivalent to", "approximately equal to"
Jose Costa Teixeira (Jan 19 2021 at 14:52):
this is not "approximately".
Yes, I'd like a standard extension because it seems common speech (not sure if is exchanged often, but then again, magistral formulas are not often exchanged)
Jose Costa Teixeira (Jan 19 2021 at 14:53):
seems that a modifier extension is not possible - that is what I read from Lloyd's comments in the other stream. Which would be a shame
Jose Costa Teixeira (Jan 19 2021 at 14:54):
@Melva Peters have you used magistral formulas in Canada? If so, how do you transmit the "ad" in
"rem constituens: ad 100 ml"
Alexander Zautke (Jan 19 2021 at 15:26):
It could be in the same extension, right?
Rik Smithies (Jan 19 2021 at 15:29):
@Jose Costa Teixeira , no it's not "approximately", but that is a similar concept that I think may be needed in the same place.
@Alexander Zautke yes I think so, for all of these comparators.
"sufficient quantity" is not only used in magistrals but also in some commercially available product definitions.
Lloyd McKenzie (Jan 19 2021 at 15:31):
@Jean Duteau @Melva Peters Has Pharmacy handled this?
Lloyd McKenzie (Jan 19 2021 at 15:31):
In v3, it would have been a null flavor of QS ('Sufficient Quantity')
Jose Costa Teixeira (Jan 19 2021 at 15:54):
Rik Smithies said:
"sufficient quantity" is not only used in magistrals but also in some commercially available product definitions.
That's the one. It's a common thing also there indeed
Melva Peters (Jan 19 2021 at 16:04):
I don't think we have a way to handle this. @Jose Costa Teixeira I think you should add a new Jira Issue.
Jean Duteau (Jan 19 2021 at 17:29):
We explicitly added the capability for this. Medication.ingredient.strength[x] has a strengthCodeableConcept to handle this. Our example value set has QS (as much as sufficient) and Trace (very small amount).
Jean Duteau (Jan 19 2021 at 17:30):
we also changed strength from being just a Ratio to being a choice of Ratio, Quantity, or CodeableConcept.
Rik Smithies (Jan 19 2021 at 17:52):
That's good for QS, which answers this thread it seems. That approach should be put into Ingredient resource also. But we would need a different solution for the other thread "approximately equal".
Melva Peters (Jan 19 2021 at 22:29):
Thanks Jean, I had forgotten that! :+1:
Lin Zhang (Jan 20 2021 at 00:55):
Maybe need two ext elements to capture the addition and the resulting volume.
Jose Costa Teixeira (Jan 20 2021 at 09:28):
Jean Duteau said:
We explicitly added the capability for this. Medication.ingredient.strength[x] has a strengthCodeableConcept to handle this. Our example value set has QS (as much as sufficient) and Trace (very small amount).
How does that work? I need to express "qs 100 ml" - the CodeableConcept needs to prefix the quantity, not replace it
Jose Costa Teixeira (Jan 20 2021 at 09:29):
I don't see how it covers the case I mentioned
Jose Costa Teixeira (Jan 20 2021 at 09:32):
Would the medication.amount be 100 ml and strengh "qs"?
Jose Costa Teixeira (Jan 20 2021 at 09:36):
Technically that could work, but that is not my reading of how systems work. in a SPC or formula, the description is not (i think)
Quantity: 100 ml
drug A : 5 ml
drug B: 1 g
excipient: as much as needed
Quantity: 100 ml
drug A : 5 ml
drug B: 1 g
excipient: as much as needed for 100 ml
Jose Costa Teixeira (Jan 20 2021 at 09:37):
this is a simple example, I'm not sure there are implications, e.g.
drug A : 5 ml
drug B: 1 g
sweetener: as much as needed
excipient: as much as needed to 100 ml
Jose Costa Teixeira (Jan 20 2021 at 09:39):
seems "sufficient quantity" is not the same as "sufficient quantity to"
Jose Costa Teixeira (Jan 20 2021 at 09:41):
I don't know pharma latin, but I checked in a few other languages, and all of them are like "qsp" "qbp" "cbp" - meaning "the quantity sufficient to".
Jose Costa Teixeira (Jan 20 2021 at 21:05):
...right?
Rik Smithies (Jan 20 2021 at 21:28):
I have only see the use case for when there is no quantity specific to the "as much as needed" - the one in your "sweetener" example (#3). There is only an overall total, or sometimes there is no total, just strengths (per unit volume or whatever), and a QS. That is what I had assumed that you were meaning. Sufficient quantity seems to naturally take no value in itself, so maybe yours is not that. Where are you finding this example?
Jose Costa Teixeira (Jan 21 2021 at 16:47):
https://sante.public.lu/rcp/510.pdf
Jose Costa Teixeira (Jan 21 2021 at 16:48):
https://ec.europa.eu/health/documents/community-register/2005/200505199250/anx_9250_fr.pdf
Jose Costa Teixeira (Jan 21 2021 at 16:48):
https://ec.europa.eu/health/documents/community-register/2005/200505199250/anx_9250_fr.pdf
Jose Costa Teixeira (Jan 21 2021 at 16:48):
http://base-donnees-publique.medicaments.gouv.fr/affichageDoc.php?specid=60307242&typedoc=R
Jose Costa Teixeira (Jan 21 2021 at 16:49):
(just a few random examples)
Jose Costa Teixeira (Jan 21 2021 at 16:49):
the "sufficient quantity " comes with " for 1ml"
Jose Costa Teixeira (Jan 21 2021 at 16:51):
A bottle has 5 ml, but the formulation is : "X units... + sufficient quantity for 1 ml" - if I omit that, this would be "sufficient quantity for 5 ml??"
Rik Smithies (Jan 21 2021 at 18:24):
It would help to know what current software actually currently does. If the real world has requirements that are not yet mapped to systems that implement it, then it is hard to know how (or if) FHIR should deal with this.
But anyway the data representation doesn't necessarily need to mimic the human language, not least because it is always possible to use text as well, or instead of, the computable. The Ingredient resource specifically has Strength.ConcentrationText for that sort of thing, because we know that not all strengths are computable.
Are the other strengths expressed in per 1ml? I can't really read those well enough I'm afraid. I suppose sufficient quantity of a concentration strength (per unit) would work in the units of the other strengths. We normally say "sufficient quantity" with no units. That must have some meaning, so there must be a way to know "how much to make it up to". I don't know this area enough to know if the "to an amount" is needed for the meaning or just some redundant text.
Jose Costa Teixeira (Jan 21 2021 at 18:49):
the second example comes from EMA, I think.
And in Belgium, the requirement is as I mentioned - we currently need an extension on quantity
Jose Costa Teixeira (Jan 21 2021 at 18:50):
the examples I got (sorry, it is just much easier to look using the french keyword) are like "sufficient quantity to 1 ml" and then "this comes in a 5 ml bottle"
Jose Costa Teixeira (Jan 21 2021 at 18:51):
most commonly the examples are "ingredients per 1 ml": .. and there we have the sufficient quantity (which in this case is redundant, but it is still there explicitly)
Lin Zhang (Jan 22 2021 at 13:47):
The formulation is kind-of similar to a concentration/(preparation instruction) such as 7 units/ml, but the volume the patient needs is the sufficient quantity such as 5ml. Am I correct?
Jose Costa Teixeira (Jan 24 2021 at 01:48):
In my example, these are both quantities of the product, without referring to any specific patient
Lin Zhang (Jan 24 2021 at 02:31):
That's possible
Jose Costa Teixeira (Jan 27 2021 at 08:17):
so, can anything be done here? should I submit a CR?
Lloyd McKenzie (Jan 27 2021 at 15:21):
@Jean Duteau
Jean Duteau (Jan 27 2021 at 15:31):
it appears that what can currently be done doesn't satisfy your use cases, so yes a Jira issue seems your next course of action
Jose Costa Teixeira (Feb 02 2021 at 22:07):
Incidentally, today a pharmacist sent this example as a common requirement for magistral preparations:
Ranitidine.HCL 1.675g
Mononatriumfosfaat dihydraat 0.3g
Dinatriumfosfaat dihydraat 1.3g
<Water> 30g
<Orange flavour> qs
<Simple preserve syrup> ad 100ml
dt 300 ml
Jose Costa Teixeira (Feb 02 2021 at 22:09):
Half translated but shows the idea:
- Orange flavour - sufficient quantity
- Preserve syrup - sufficient quantity to make 100 ml
total dose quantity is 300 ml
Jose Costa Teixeira (Feb 02 2021 at 22:09):
I was personally less familiar with "qs" than "ad" - every other medication product has "ad" as a quantity modifier, and this is common in several countries.
Jean Duteau (Feb 02 2021 at 22:11):
@Jose Costa Teixeira did you raise a JIRA issue? I'm working on the MnM agenda and don't see an issue about this there.
Jose Costa Teixeira (Feb 02 2021 at 22:11):
I don't think this can be addressed with strength[x], so my idea would be to add a standard extension (or something core) to quantity.
Jose Costa Teixeira (Feb 02 2021 at 22:12):
I'm creating the issue, I just need to see which part of the specification this goes to. Hence this quick check here
Jean Duteau (Feb 02 2021 at 22:13):
you want advice on Quantity which is a datatype, so it would go to MnM (assuming that is what you are asking).
Jose Costa Teixeira (Feb 02 2021 at 22:14):
I think so (unless people think this would be for pharma which would be imply a bigger change, I think)
Jose Costa Teixeira (Feb 02 2021 at 22:14):
data types are managed by FHIR-I
Jean Duteau (Feb 02 2021 at 22:16):
I thought you were asking a methodology question, but if not, then you are right that FHIR-I is the right place.
Jose Costa Teixeira (Feb 02 2021 at 22:45):
Jose Costa Teixeira (Feb 02 2021 at 22:45):
Achievement unlocked: include the word "romance" in a Jira ticket.
Lloyd McKenzie (Feb 03 2021 at 06:55):
And only a little before Valentine's Day... :)
Last updated: Apr 12 2022 at 19:14 UTC
