Personal Health Device Implementation Guide
1.0.0 - STU 1 International flag

Personal Health Device Implementation Guide, published by HL7 International / Health Care Devices. This guide is not an authorized publication; it is the continuous build for version 1.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/phd/ and changes regularly. See the Directory of published versions

PHD Coded Enumeration Observation Profile

The Coded Enumeration Observation Profile is used when the PHD metric measurement represented by one of a limited set of codes. Examples of a coded measurement would be the Glucose Monitor meal context associated with a glucose concentration measurement. The code would indicate one of fasting, preprandial, postprandial, bedtime, etc. Coded measurements are often associated with other measurements.

The measurement is a code when the PHD metric contains one of the following attributes:

Attribute Value Additional Information
Enum-Observed-Value-Simple-OID 16-bit term code The partition is obtained from the Type attribute or the Enum-Observed-Value-Partition attribute
Enum-Observed-Value 16-bit term code when an OID The partition is obtained from the Type attribute or the Enum-Observed-Value-Partition attribute

The Enum-Observed-Value-Simple-OID attribute is used when the measurement is itself an MDC code. This type of measurement is most common when reporting the context of another measurement, for example the meal context of a glucose measurement and/or the current state of health. Enumeration measurements are used when there is a finite set of fixed possibilities for the measurement to take. The attribute contains only the 16-bit term code. The partition typically comes from the Type attribute or, in special cases, the Enum-Observed-Value-Partition attribute.

The Enum-Observed-Value attribute is a complex attribute and can be any one of the three possible enumeration measurements. There is an element in the structure which indicates which type of enumeration it is. If it is an ‘OID’ type it has an MDC term code. The attribute also has its own metric-id value telling what it is and status value. The metric-id value replaces the term code given by the Type attribute for the type of measurement (not the measurement!) and the status value replaces the Measurement-Status attribute.

The structure definition for this profile is given here

Mapping Coded Enumerations to FHIR

The following table shows how the coded enumeration attributes are mapped to FHIR.

Attribute FHIR coding
Enum-Observed-Value-Simple-OID.value Observation.valueCodeableConcept.coding.code
Enum-Observed-Value.value
Enum-Observed-Value.metric-id
Enum-Observed-Value.status		 Observation.valueCodeableConcept.coding.code
effects Observation.code see Obtaining the Observation.code
see Measurement Status in PHD Base Observation Profile

Meta Data Profile

The uploader shall populate the Observation.meta.profile with http://hl7.org/fhir/uv/phd/StructureDefinition/PhdCodedEnumerationObservation indicating this resource is generated following the PHD Implementation Guide.

Conditional Create Identifier Generation

For a general description of the PHD Observation Identifier see the “PHD Observation Identifier” section in [PHD Base Observation Profile](BaseObservationProfile.html The table below lists the items that make up the identifier.

Entry value Additional information
device “PHD Device.identifier.value” This value is the PHD IEEE EUI-64 system identifier
patient “Patient.identifier.value-Patient.identifier.system” or
provided logical id		 The dashes are part of the identifier.
When the service provider gives the PHG a pre-determined patient logical id the PHG creates no Patient resource and has no patient information. In that special case the provided logical id is used
type “Observation.code.coding.code” See Obtaining the Observation.code
value “Observation.valueCodeableConcept.coding.code” or
“Observation.dataAbsentReason.coding.code”		 The enumeration 32-bit MDC code of the measurement or
the data absent reason code if there is no value
reported PHD timestamp “timestamp” See Generating the PHD Reported Time Stamp
supplemental types “Supplemental-Types.N-“ A sequence of 32-bit MDC codes separated by a dash

The final identifier is made by concatenating the entries above as follows:

  • “device-patient-type-value-reported PHD timestamp-supplemental types”

Additional Enumeration Measurement Information

There are no additional descriptive attributes that are unique to the Enumeration type of measurement.

Examples:

The Glucose Meal Context example shows a glucose meal context measurement. The meal context is a limited set of coded values indicating when the measurement was taken relative to a meal. The measurement SHOULD have an Observation.derivedFrom entry pointing to the glucose concentration measurement to which it refers. The fact it does not was a miss in the Glucose specialization standard and has since been corrected, but the device that reported this measurement was made before the change in the standard.

The Other Profiles