MedicationStatement with multiple Dosages


Hi All,

I am trying to find an example MedicationStatement with multiple dosages. For example, if a patient in Inpatient ward was prescribed with omeprazole oral capsule 20mg, 2 times a day (8AM and 9PM) for 7 days, then there are 14 doses.

If I need to represent this in Medication statement, Should there be 14 dosages in MedicationStatement ?


(Rik Smithies) #2

No. The dosage includes the concept of a single pattern that works out to be multiple dosing events.


Thank you for the response,
if the dosage has single pattern like 2 times a day for 7 days.

  1. how the time is calculated - for Inpatient medication time depends on the Hospital / ward.
  2. If the dosing events has different times how this can be communicated in the Medication Statement ? for example some this medicine could be administrated 8AM ?


(Kev Mayfield) #4

Have you looked at this

I’ve not read it in detail but it sounds similar

(ian) #5

That’s correct - still in development but should cope with that dosage instruction ok. Bear in mind that all current GP systems only carry a single dose/text string, and the use of structurted dosage is very inconsistent in secondary care systems. We are very close to figuring out how to do this in a system-neutral way in FHIR and we have proved it can be done in openEHR :wink: The dose/timing models are very similar.

@Tharma- your example is a single dosage instruction, actioned by 14 administrations. You would not normally carry all of these adminstration events with a MedicationStatement (though you can as linked resources) much more common is to carry e.g. details of the last administration.

(Rik Smithies) #6

I don’t want to give the impression that FHIR is waiting for a new dose syntax before it can be used.

If you have a good understanding of all your own system’s data items you can map them onto the data items of FHIR now.

There are many examples of complex FHIR dosage already in the standard.

But mapping between complex models is never easy, and the new dose syntax will help if you are trying to standardise the way dose is represented across a wide range of settings and systems - many of which don’t capture that data in a structured way currently.

I do know there is a need for that work in the UK, to solve a wider problem, but I am not sure that is what the questioner is trying to do here.

To add to Ian’s answers about the specifics:

1 FHIR doesn’t calculate times. If you have that requirement you need to manage that in your own system code. However FHIR does let you represent the planned time, if there is one, and the eventual time also.

2 FHIR allows you to specify the time of the dose in the request. You can specify the actual time that it happened in a MedicationAdministration. However as we have discussed already MedicationStatement is a more general purpose, higher level summary, and would not normally cover all the times of doses. That is not its job.

(ian) #7

Hi Rik,

“I don’t want to give the impression that FHIR is waiting for a new dose syntax before it can be used.”

At one level, of course I have to agree since the resources exist … however… this is an area where the value only comes if all potential stakeholders agree on what parts to implement and how. It is such a complex area and is also heavily dependent on the particular terminology in use and national prescribing patterns. So I would argue that practical deployment has to take place within a community of practice around agreed implementation guidance.

That work is taking place in the UK and very close to being ready for deployment, albeit within the restricted context of common GP/community prescriptions.

I agree with your other answers …

Specific times/dates can be carried in the timing structures but how these are derived from more abstract timings like one tablet three times per day depends on the care setting/institution, which may have specific ‘drug round’ times.

(Rik Smithies) #8

Hi Ian

I meant to say that while obviously everyone will need analysis, mapping, consensus etc, you are not bound to this particular dose syntax in order to use FHIR.

The question wasn’t UK specific as I understood it (although this is a UK hosted board).


HI @riksmithies ,

Are you saying that MedicationAdministration resource can be used to represent already administrated dosing events and planned / future dosing events as well?