2. STU3 Limitation - Defining a maximum dose per course
Workaround: Use a free-text `Dosage.additionalInstruction`.
A maximum dose for three scenarios is supported within the STU3 Dosage structure;
maxDosePerPeriod
- define a maximum dose over a given period of timemaxDosePerAdministration
- defines a maximum dose per administrationmaxDosePerLifetime
- defines the maximum dose during the lifetime of the patient
Not currently supported is how to define a maximum dose per course.
With the current STU3 Dosage structure, a maximum dose per course would have to be conveyed in free-text using the Dosage.additionalInstruction
.
<!-- Defining a maximum dose per course --> <!-- Example: Colchicine 500microgram tablets, 500 micrograms, 2 to 4 times a day until symptoms relieved, maximum 6 mg per course, do not repeat course within 3 days --> <MedicationRequest xmlns="http://hl7.org/fhir"> <id value="f27b260e-8bdf-11eb-8dcd-0242ac130003" /> <contained> <Medication> <id value="med1" /> <code> <coding> <system value="http://snomed.info/sct" /> <code value="330079002" /> <display value="Colchicine 500microgram tablets" /> </coding> </code> </Medication> </contained> <status value="active" /> <intent value="order" /> <medicationReference> <reference value="#med1" /> </medicationReference> <subject> <identifier> <system value="https://fhir.nhs.uk/Id/nhs-number" /> <value value="9999999999" /> </identifier> </subject> <dosageInstruction> <additionalInstruction> <text value="Maximum dose per course 6 mg" /> </additionalInstruction> <additionalInstruction> <text value="Do not repeat course for 3 days" /> </additionalInstruction> <patientInstruction value="Until symptoms relieved" /> <timing> <repeat> <frequency value="2" /> <frequencyMax value="4" /> <period value="1" /> <periodUnit value="d" /> </repeat> </timing> <doseQuantity> <value value="500" /> <unit value="microgram" /> <system value="http://unitsofmeasure.org" /> <code value="ug" /> </doseQuantity> </dosageInstruction> </MedicationRequest>
{ "resourceType": "MedicationRequest", "id": "f27b260e-8bdf-11eb-8dcd-0242ac130003", "contained": [ { "resourceType": "Medication", "id": "med1", "code": { "coding": [ { "system": "http://snomed.info/sct", "code": "330079002", "display": "Colchicine 500microgram tablets" } ] } } ], "status": "active", "intent": "order", "medicationReference": { "reference": "#med1" }, "subject": { "identifier": { "system": "https://fhir.nhs.uk/Id/nhs-number", "value": "9999999999" } }, "dosageInstruction": [ { "additionalInstruction": [ { "text": "Maximum dose per course 6 mg" }, { "text": "Do not repeat course for 3 days" } ], "patientInstruction": "Until symptoms relieved", "timing": { "repeat": { "frequency": 2, "frequencyMax": 4, "period": 1, "periodUnit": "d" } }, "doseQuantity": { "value": 500, "unit": "microgram", "system": "http://unitsofmeasure.org", "code": "ug" } } ] }
MedicationRequest.id[0] | f27b260e-8bdf-11eb-8dcd-0242ac130003 |
MedicationRequest.contained[0].id[0] | med1 |
MedicationRequest.contained[0].code[0].coding[0].system[0] | http://snomed.info/sct |
MedicationRequest.contained[0].code[0].coding[0].code[0] | 330079002 |
MedicationRequest.contained[0].code[0].coding[0].display[0] | Colchicine 500microgram tablets |
MedicationRequest.status[0] | active |
MedicationRequest.intent[0] | order |
MedicationRequest.medication[0].reference[0] | #med1 |
MedicationRequest.subject[0].identifier[0].system[0] | https://fhir.nhs.uk/Id/nhs-number |
MedicationRequest.subject[0].identifier[0].value[0] | 9999999999 |
MedicationRequest.dosageInstruction[0].additionalInstruction[0].text[0] | Maximum dose per course 6 mg |
MedicationRequest.dosageInstruction[0].additionalInstruction[1].text[0] | Do not repeat course for 3 days |
MedicationRequest.dosageInstruction[0].patientInstruction[0] | Until symptoms relieved |
MedicationRequest.dosageInstruction[0].timing[0].repeat[0].frequency[0] | 2 |
MedicationRequest.dosageInstruction[0].timing[0].repeat[0].frequencyMax[0] | 4 |
MedicationRequest.dosageInstruction[0].timing[0].repeat[0].period[0] | 1 |
MedicationRequest.dosageInstruction[0].timing[0].repeat[0].periodUnit[0] | d |
MedicationRequest.dosageInstruction[0].dose[0].value[0] | 500 |
MedicationRequest.dosageInstruction[0].dose[0].unit[0] | microgram |
MedicationRequest.dosageInstruction[0].dose[0].system[0] | http://unitsofmeasure.org |
MedicationRequest.dosageInstruction[0].dose[0].code[0] | ug |
MedicationRequest |
id : f27b260e-8bdf-11eb-8dcd-0242ac130003 |
contained |
id : med1 |
code |
coding |
system : http://snomed.info/sct |
code : 330079002 |
display : Colchicine 500microgram tablets |
status : active |
intent : order |
medication |
reference : #med1 |
subject |
identifier |
system : https://fhir.nhs.uk/Id/nhs-number |
value : 9999999999 |
dosageInstruction |
additionalInstruction |
text : Maximum dose per course 6 mg |
additionalInstruction |
text : Do not repeat course for 3 days |
patientInstruction : Until symptoms relieved |
timing |
repeat |
frequency : 2 |
frequencyMax : 4 |
period : 1 |
periodUnit : d |
dose |
value : 500 |
unit : microgram |
system : http://unitsofmeasure.org |
code : ug |