Dose syntax implementation guidance for FHIR STU3

This guidance is under active development by NHS Digital and content may be added or updated on a regular basis.

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 not mg.

  • 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 becomes 2 hours.

  • Do not express other units of measure in the plural as this introduces complications with units such as microgram per millilitre or microgram 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.

back to top