HL7v2 and FHIR Messages - Prescriptions (RDE_O11) and Pathology (ORU_R01)


After some feedback. I’m working on two FHIR Messaging interfaces, they are influenced by HL7v2 messages (and HL7v3 for prescriptions).

Links to the definitions

Prescription Order
Unsolicited Observations - Pathology

Is this the way to go? It’s keeping messaging alive and not using the more modern restful but it’s practical especially for sending data outside of an organisation (all the resources are bundled together)

Have also started to look at mapping HL7v2 PV1 to FHIR Encounter. Digital Medicines Implementation Guide This is very basic and intent is to align with HL7.FHIR.UV.V2-TOFHIR\Message Maps - FHIR v4.0.1

(Note: links are subject to change, shown for illustration and do not indicate a definite path)


Is it intended that these would be actual electronic prescriptions? Or just a message to inform someone about a prescription in the patient’s record?

Good question.

The prescription-order is intended to be the order and will be sent to a pharmacy via EPS (after conversion to HL7v3). Similarly the path results message is the results of an order.

I do think we have a need for notifications such as patient discharged/attended or discharge letter created (and we should use a standard set of messages). I don’t think these should contain details, so if a patient had medications issued at discharge it wouldn’t be in the notification.
If you want discharge meds you need to look it up either by retrieving the discharge letter or by querying the system/provider that sent the discharge notification.

I may have the balance wrong here?
I’m favouring actions/orders/referrals and results to follow existing HL7v2 patterns, notifications of key events (still similar to HL7 v2) and moving away from information/data transfers (I’d probably also move away from exchanging documents but it’s a bit of a grey area)

If it’s going to be the legal electronic prescription it needs to contain the Advanced Electronic Signature (AES) otherwise it breaks the law as it isn’t a legal prescription.
The Medicines for Human Use (Prescribing) Order 2005 Statutory Instrument 2005 No. 765
(7) In this Article -
“advanced electronic signature” means an electronic signature
which is -
(a) uniquely linked to the signatory,

          (b) capable of identifying the signatory,

          (c) created using means that the signatory can maintain under his 
          sole control, and

          (d) which is linked to the data to which it relates in such a 
          manner that any subsequent change of data is detectable;

Essentially that is all the legislation says in terms of standards for an electronic signature.

I think EPS effectively uses a certificate to both hold the information and to identify any changes. Not sure you could convert it from FHIR without breaking that.

Additionally if the prescription is going to be a NHS FP10 style prescription (GP to Pharmacist) then the GP must use EPS, again that’s in the legislation.

Unfortunately prescribing in England and Wales at least is very locked down with legislation.

I don’t know if there are any similar requirements for pathology. I suspect that is much more open!

Thats held in the Provenance section of the message.

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