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.
Medication Component Parts
Medication Name
CUI recommends the medication name is formatted in bold. The text narrative supports XHTML mark-up therefore the medication name could be marked-up within <b> HTML tags.
If using a VTM concept the name will just be the name of the VTM.
Paracetamol
If using a VMP concept the name will include the strength and form. The unit of measure associated with the strength may use an abbreviated term as this is part of the dm+d standard.
Paracetamol 1g tablets
If using an AMP concept the name will be the AMP description which includes the supplier name. The unit of measure associated with the strength may use an abbreviated term as this is part of the dm+d standard.
Paracetamol 1g tablets (Dawa Ltd)
Medication Form
(if not implied within a VMP/AMP name)
No additional formatting required.
Trade Family Name
Although not suppported yet within FHIR profiled resources, when available, format into UPPER case.
ZOMORPH
Dosage Structure Component Parts
method
No additional formatting required.
doseQuantity / doseRange
Express a doseQuantity as “{quantity} {units}”
50 milligram
2 tablets
Express a doseRange as “{low_quantity} to {high_quantity} {high_units}”
20 to 40 millilitre
rateRatio / rateRange / rateQuantity
When the denominator value is 1 (one) express a rateRatio as “at a rate of {numerator_value} per {denominator_unit}”. Otherwise express as “at a rate of {numerator_value} every {denominator_value} {denominator_unit}”. Express the time-based units in plural when required.
at a rate of 30 millitre per hour
at a rate of 30 millitre every 2 hours
Express a rateRange as “at a rate of {low_value} to {high_value} {high_units}”
at a rate of 1 to 2 liter per minute
Express a rateQuantity as “at a rate of {value} {units}”
at a rate of 1 microgram per kilogram per hour (Note. This example uses the UCUM unit “microgram per kilogram per hour”)
duration, durationMax
Express a duration as “over {value} {units}”. Express the time-based units in plural when required. Where a durationMax is defined, append with “(maximum {max_value} {max_units})”.
over 8 hours
over 4 hours (maximum 6 hours)
frequency, frequencyMax, period and periodMax
Generic Rules
Express the combination of frequency and period as “{frequency} times every {period_value} {period_unit}”.
3 times every 8 hours
Where a frequencyMax is defined, express as “{frequency} to {frequencyMax} times every {period_value} {period_unit}”.
2 to 3 times every 8 hours
Where a periodMax is defined, express as “{frequency} times every {period_value} to {periodMax_value} {period_unit}”.
3 times every 6 to 8 hours
Where both frequencyMax and periodMax are defined, express as “{frequency} to {frequencyMax} times every {period_value} to {periodMax_value} {period_unit}”.
2 to 3 times every 6 to 8 hours
Where a frequencyMax is defined without a frequency then express as “up to {frequencyMax} times…”.
up to 3 times a day
up to 4 times every 8 hours
up to 6 times every 3 to 4 weeks
Where a periodMax is defined without a period then express as “{frequency} times up to {periodMax_value} {period_unit}”.
3 times up to 8 hours
2 to 3 times up to 8 hours
Note. The omission of both a frequency and frequencyMax when either a period or periodMax is present is allowed as per cardinality rules but should be prevented in practice as does not result in a logical timing instruction.
Special Cases
When period is 1 (one) without a frequency, express as “daily”, “weekly”, “monthly” or “annually” depending on the periodUnit. In theory, the periodUnit could be "s" (seconds) or "min" (minutes) but the use of these without an associated frequency is illogical.
daily
weekly
When frequency is 1 (one) without a period, express as “once”.
once
When frequency is 2 (two) defined without a period, express as “twice”.
twice
When frequency is greater than 2 (two) and defined without a period, express as “{frequency} times”.
3 times
When frequency and period are both 1 (one) express as “once a {period_unit}”.
once a week
When frequency is 1 (one) and period is greater than 1 (one) express as “every {period_value} {period_unit}” or “every {period_value} to {periodMax_value} {period_unit}”.
every 8 hours
every 6 to 8 hours
When frequency is 2 (two) and period is 1 (one) express as “twice a {unit}”.
twice a day
When frequency is greater than 2 (two) and period is 1 (one) express as “{frequency} times a {unit}”.
4 times a day
When frequency is 2 (two) and period is greater than 1 (one) express as “twice every {period_value} {period_unit}” or “twice every {period_value} to {periodMax_value} {period_unit}”.
twice every 8 hours
twice every 6 to 8 hours
offset, when(s)
Any offset will be defined as a number of minutes. If this equates to a whole number of hours or days then express as the number of hours (=60 minutes) or days (=1440 minutes). Use the singular or plural expression of time when required. Separate multiple statements with a comma and use the word “ and “ to separate the final two statements.
The FHIR event timing value-set used for when should have descriptions modified to make them more human readable. Remove the text “event occurs [offset]” and “(from the Latin…)” from the descriptions.
Simplify the following value-set definitions;
- Display: “After Sleep” - Use definition “once asleep”
- Display: “HS” - Use definition “before sleep”
- Display: “WAKE” - Use definition “upon waking”
- Display: “C” - Use Definition “at a meal”
- Display: “CM” - Use Definition “at breakfast”
- Display: “CD” - Use Definition “at lunch”
- Display: “CV” - Use Definition “at dinner”
Express as “{offset_value} minute(s)/hour(s)/day(s) {modified_when_value-set}”.
at breakfast
30 minutes before a meal
1 hour before sleep
2 hours after breakfast
during the morning and during the evening
dayOfWeek(s)
Express dayOfWeek statements as “on {dayOfWeek}” using the full description from the FHIR value-set, i.e. “mon” = “Monday”. Separate multiple statements with a comma and use the word “ and “ to separate the final two statements.
on Monday
on Monday, Wednesday and Friday
timeOfDay(s)
Express timeOfDay statements as “at {timeOfDay}”. Separate multiple statements with a comma and use the word “ and “ to separate the final two statements. If a time is expressed with :00 seconds then express just in terms of hours and minutes. Sending systems should always provide times using the 24 hour clock. Receiving systems may apply local preferences for display, i.e. 15:00 or 3:00pm.
at 10:00
at 10:00 and 15:00
route
No additional formatting required.
site
No additional formatting required.
asNeededCodeableConcept / asNeeded
Express the asNeededBoolean statement as “as required”.
as required
Express the asNeededCodeableConcept as “as required for {coded_value_description}”
as required for Migraine
boundsDuration / boundsRange
Express boundsDuration as “for {value} {units}”. Express the units in plural when required.
for 7 days
Express boundRange as “for {low_value} to {high_value} {high_units}”. Express the units in plural when required.
for 2 to 4 hours
count, countMax
Express count as “take {value} times”. If the value is 1 (one) express as “once”. If the value is 2 (two) express as “take twice”. If a countMax is define then express as “take {value} to {max_value} times”.
take 3 times
once
take twice
take 3 to 4 times
event(s)
Express event statements as “on {event_value}”. Separate multiple statements with a comma and use the word “ and “ to separate the final two statements. Local preferences can be used to display the date in dd/mm/yyyy or dd-mmm-yyyy format.
on 25/01/2019
on 25-Jan-2019
on 25/01/2019, 25/02/2019 and 25/03/2019
maxDosePerPeriod / maxDosePerAdministration / maxDosePerLifetime
Express a maxDosePerPeriod statement as “up to a maximum of {numerator_value} {numerator_unit} in {denominator_value} {denominator_unit}”. Express the time-based units in plural when required.
up to a maximum of 1000 milligram in 24 hours
Express a maxDosePerAdministration statement as “up to a maximum of {value} {unit} per dose”.
up to a maximum of 2 milligram per dose
Express a maxDosePerLifetime statement as “up to a maximum of {value} {unit} for the lifetime of patient”.
up to a maximum of 60 milligram for the lifetime of patient
additionalInstruction(s)
Separate multiple statements with a comma and use the word “ and “ to separate the final two statements.
Do not stop taking this medicine except on your doctor's advice
Dissolve or mix with water before taking and Contains aspirin
patientInstruction
No additional formatting required.
Multi-Sequence Instructions
When a complete dosing instruction is described across multiple sequences, the complete string is concatinated with each sequence. The original medication information is not repeated.
Sequential Instructions
Separate sequential instructions (where each
Anydrug - 50 milligram - once a day - oral - for 1 week, then 100 milligram - once a day - oral - for 3 weeks
Concurrent Instructions
Separate parallel instructions (where
Anydrug - 50 milligram - once a day - in the morning - oral, and 100 milligram - once a day - in the evening