This page describes a critical functional requirement for the majority of system implementations using Dose Syntax. Structured Dose Syntax information must be capable of being rendered as a human-readable text representation e.g. in a user interface or on a medicines label.
Details of the rendering requirement are highly use-case dependent and will be addressed as work in specific use-case areas develops.
This section details the logic required for a system to generate a suitable, clinically safe, complete medication plus dosage string from the coded structures.
Research References
This guidance is aligned with;
- Common User Interface (CUI) Medications line recommendations, England, May 2010
- National guidelines for on screen display of medicines information, Australia, December 2017
Note. The Australian guidelines include the use of Tall-Man within medication names which has been excluded from this guidance.
Common Principals
The following applies to the presentation of any component part of the dosage instruction;
- Always express units of measure using the full description, e.g.
milligram
notmg
. - Important: The above principal does not apply to units of measure as part of pre-coordinated dm+d concept descriptions, e.g.
Ramipril 5mg capsules
. - Always express a time-based unit of measure in the plural when applicable, e.g.
2 hour
becomes2 hours
. - Do not express other units of measure in the plural as this introduces complications with units such as
microgram per millilitre
ormicrogram per kilogram per hour
. - Where multiple statements are allowed, e.g. when or event structures, then separate each statement with a comma plus whitespace. Replace the last comma separating the final two statements with the word “ and “, e.g.
on Monday, Wednesday and Friday
.
Logicial Display Order
The order in which the structures within a CareConnect profiled resouce should be listed.
- Medication Name
- Medication Form (if not implied within a VMP/AMP name)
- Trade Family Name (if not implied within an AMP name)
Then for each dosageInstruction;
- method
- doseQuantity / doseRange
- rateRatio / rateRange / rateQuantity
- duration, durationMax
- frequency, frequencyMax, period and periodMax
- offset, when(s)
- dayOfWeek(s)
- timeOfDay(s)
- route
- site
- asNeededCodeableConcept / asNeeded
- boundsDuration / boundsRange
- count, countMax
- event(s)
- maxDosePerPeriod / maxDosePerAdministration / maxDosePerLifetime
- additionalInstruction(s)
- patientInstruction
The rules and logic for presenting each structure is detailed on the Text Generation Logic page.
Component Part Separator
In most cases, each component part of the medication instruction is separated by space-dash-space, e.g. “ - “.
Oxytetracycline 250mg tablets - 1 tablet - 4 times a day - oral
Oxytetracycline - 250 milligram - 4 times a day - oral
Exceptions are as follows;
- Use a single whitespace after a method, e.g.
Apply
- Use a single whitespace to separate between a dayOfWeek and timeOfDay, e.g.
on Monday at 10:30
Dose-to-Text Conversion Web Service
A web service is in development by NHS Digital that will implement this logic and translate a CareConnect medication-related profiled resource and return a string suitable for use as the text narrative. When available, this web service can be used by system suppliers during their software prototyping and design phases. It should also be suitable as an operational service so that system suppliers so not have to implement this complex logic within their own solutions.
A demonstrator and associated API documentation has been provided by the North of England Commissioning Support Unit that aligns with this guidance.