Upon creating a CarePlan for a particular Patient (see Creating Care Plans), the CarePlan’s ServiceRequest resources inherit a copy of any measurement ranges defined in the PlanDefinition’s ActivityDefinition resources, see https://ehealth-dk.atlassian.net/wiki/spaces/EDTW/pages/1696137281/Managing+Telemedicine+Packages#Defining-measurement-ranges. It is expected that a Practitioner performs or considers Patient-specific adjustment of the measurement ranges in ServiceRequest resources beyond this point, possibly continuously going forward.
Please refer to the description of measurement ranges for details on how to define adjacent and possibly (but not typically) overlapping measurement ranges.
The following describes how to set up a measurement range on a single ServiceRequest. In case the CarePlan contains multiple ServiceRequest for the same activity code, copying of changes to measurement ranges can be relevant. Multiple ServiceRequest in the same CarePlan or sub-CarePlan can refer to the same ActivityDefinition (through ServiceRequest.definition
) and/or each refer to an individual ActivityDefinition with same ActivityDefinition.code
.
It is likely to be expected from a Telemedicine Solution used by an employee that it addresses copying of changes in measurement ranges to other ServiceRequest in the same CarePlan/sub-Careplan having the same activity code. As copying is not always the desired effect, prompting of user when to do that should be considered.
Preparing Details for Setting Measurement Ranges
In the descriptions below, measurement ranges can be expressed in the same measurement unit (system
, code
, and displayable unit
) as the measurement would be submitted with. The proper measurement unit in this case can be determined using the approach outlined in https://ehealth-dk.atlassian.net/wiki/spaces/EDTW/pages/2235432961/Interactions+with+the+Terminology+Service#Determining-the-proper-code%2C-system-and-unit-for-Quantity.
If the used measurement unit existing measurement ranges expressed in the same measurement unit differ from what can be determined with the approach referenced above, the measurement unit of existing measurement ranges should be used. There is little sense in expressing, say, an absolute red alarm type (see below) measurement range in multiple measurement units.
Setting up Absolute Measurement Ranges
An absolute measurement range is set up by adding a ehealth-referenceRange structure to ServiceRequest.ehealth-referenceRange
where:
ehealth-referenceRange.type
is a Coding with:system
:http://ehealth.sundhed.dk/cs/reference-range-type
code
:RAL
orGAL
, for red alarm absolute measurement range and yellow alarm absolute measurement range, respectively.
ehealth-referenceRange.low
and/or.high
is a:a SimpleQuantity where:
value
: the integer or decimal value for the low/high boundaryunit
:<same unit as measured value is expressed with>
system
:<same system as measured value is expressed with>
code
:<same code as measured value is expressed with>
Setting up Relative Measurement Ranges and a Reference Base
A relative measurement range is set up by adding a ehealth-referenceRange structure to ServiceRequest.ehealth-referenceRange
where:
ehealth-referenceRange.type
is a Coding with:system
:http://ehealth.sundhed.dk/cs/reference-range-type
code
:RELRAL
orRELGAL
, for red alarm relative measurement range and yellow alarm relative measurement range, respectively.
ehealth-referenceRange.low
and/or.high
is either of:a SimpleQuantity for a percentage change (stated as percent point change to measurement already expressed in percent) compared to the reference base where:
value
: the integer or decimal value for the low/high boundaryunit
:percent point
system
:http://ehealth.sundhed.dk/cs/ehealth-unit-code
code
:percentpoint
a SimpleQuantity for a percentage change (stated as percent change to measurement not already expressed in percent) compared to the reference base where:
value
: the integer or decimal value for the low/high boundaryunit
:percent
system
:http://unitsofmeasure.org
code
:%
a SimpleQuantity for a relative change compared to the reference base where:
value
: the integer or decimal value for the low/high boundaryunit
:<same unit as measured value is expressed with>
system
:<same system as measured value is expressed with>
code
:<same code as measured value is expressed with>
A relative measurement range states a change relative to some reference base. This way, a measured value can be compared to a reference base taking the relative measurement range into account.
There are several ways to find a reference base:
searching for a prior, measured value, say, the highest/lowest/most recent/oldest value in some given period of time
a derivate, say, an average of measured values in some given period of time
a designated value, either copied from and/or referencing a measured value
To add a designated reference base, create a FHIR Goal resource with:
status
:accepted
description
: A Coding with:code
:reference-value
system
:http://ehealth.sundhed.dk/cs/goal-description
subject
: Reference to PatientstartDate
: A datetime representing the starting point at which this reference base is applicabletarget.measure
: Coding (the same ascode
in the ServiceRequest as the relative measurement range is defined in)target.detailQuantity
: A Quantity containing the reference base valueaddresses
: Reference to ServiceRequest (the same ServiceRequest as the relative measurement range is defined in)addresses
: Reference to the Observation from which the value intarget.detailQuantity
has been copied (if that is the case)
A reference to the Goal shall then be added to the CarePlan (same CarePlan that references the ServiceRequest) to:
CarePlan.goal
Over time, the relative measurement ranges can change and new Goal resources can be created and added to the CarePlan.
Example use of relative measurement range stated in percent point.
A measurement of oxygen saturation is submitted as an Observation where the Observation.valueQuantity
is a Quantity with:
value
:88
unit
:percent
system
:http://unitsofmeasure.org
code
:%
A red alarm relative measurement range given as zero to -5 percent point is stated as:
ehealth-referenceRange.type
is a Coding with:system
:http://ehealth.sundhed.dk/cs/reference-range-type
code
:RELRAL
for red alarm relative measurement range type
ehealth-referenceRange.low
is a SimpleQuantity with:value
: -5.0unit
:percent point
system
:http://ehealth.sundhed.dk/cs/ehealth-unit-code
code
:percentpoint
ehealth-referenceRange.high
is a SimpleQuantity with:value
: -2.0unit
:percent point
system
:http://ehealth.sundhed.dk/cs/ehealth-unit-code
code
:percentpoint
A reference base could be defined as a Goal where Goal.target.detailQuantity
is a Quantity with:
value
:92
unit
:percent
system
:http://unitsofmeasure.org
code
:%
Because the measured value 88% is within a range of [-5; -2] percent point relative to the reference base value 92%, this would constitute a value which lies within the red alarm relative measurement range.
If the designated reference base was instead 95%, the measured value of 88% would not be within the red alarm relative measurement range.