RDC Interoperability Guide
1.0.0

rdc-Observation-CGM-calibrated

{
    "resourceType": "Observation",
    "id": "rdc-Observation-CGM-calibrated",
    "meta": {
        "profile":  [
            "https://roche.com/fhir/iop/StructureDefinition/rdc-Observation-CGM"
        ]
    },
    "extension":  [
        {
            "url": "https://roche.com/fhir/iop/StructureDefinition/ext-CalibrationStatus",
            "valueString": "calibrated"
        }
    ],
    "status": "final",
    "code": {
        "coding":  [
            {
                "system": "http://snomed.info/sct",
                "code": "434910001",
                "display": "Interstitial fluid glucose concentration (observable entity)"
            }
        ]
    },
    "subject": {
        "reference": "Patient/34605fdc-74aa-4587-a5f0-92e6c5f64527"
    },
    "effectivePeriod": {
        "start": "10/14/2020 01:01:00",
        "end": "10/14/2020 01:04:00"
    },
    "valueSampledData": {
        "origin": {
            "value": 0,
            "unit": "mg/dL",
            "system": "http://unitsofmeasure.org",
            "code": "mg/dL"
        },
        "interval": 60000,
        "intervalUnit": "ms",
        "dimensions": 1,
        "data": "100 99 89 89",
        "extension":  [
            {
                "url": "https://roche.com/fhir/iop/StructureDefinition/ext-SampledDataTimestamps",
                "valueString": "2020-10-14T02:01:00+01:00 2020-10-14T02:02:00+01:00 2020-10-14T02:03:00+01:00 2020-10-14T02:04:00+01:00"
            },
            {
                "url": "https://roche.com/fhir/iop/StructureDefinition/ext-CGMFlags",
                "valueString": "HI; X; X; LO"
            }
        ]
    },
    "device": {
        "reference": "Device/6ae8bff3-910a-419d-96f6-de0e8fd1d64d"
    }
}
<Observation xmlns="http://hl7.org/fhir">
    <id value="rdc-Observation-CGM-calibrated" />
    <meta>
        <profile value="https://roche.com/fhir/iop/StructureDefinition/rdc-Observation-CGM" />
    </meta>
    <extension url="https://roche.com/fhir/iop/StructureDefinition/ext-CalibrationStatus">
        <valueString value="calibrated" />
    </extension>
    <status value="final" />
    <code>
        <coding>
            <system value="http://snomed.info/sct" />
            <code value="434910001" />
            <display value="Interstitial fluid glucose concentration (observable entity)" />
        </coding>
    </code>
    <subject>
        <reference value="Patient/34605fdc-74aa-4587-a5f0-92e6c5f64527" />
    </subject>
    <effectivePeriod>
        <start value="2020-10-14T02:01:00+01:00" />
        <end value="2020-10-14T02:04:00+01:00" />
    </effectivePeriod>
    <valueSampledData>
        <extension url="https://roche.com/fhir/iop/StructureDefinition/ext-SampledDataTimestamps">
            <valueString value="2020-10-14T02:01:00+01:00 2020-10-14T02:02:00+01:00 2020-10-14T02:03:00+01:00 2020-10-14T02:04:00+01:00" />
        </extension>
        <extension url="https://roche.com/fhir/iop/StructureDefinition/ext-CGMFlags">
            <valueString value="HI; X; X; LO" />
        </extension>
        <origin>
            <value value="0" />
            <unit value="mg/dL" />
            <system value="http://unitsofmeasure.org" />
            <code value="mg/dL" />
        </origin>
        <interval value="60000" />
        <intervalUnit value="ms" />
        <dimensions value="1" />
        <data value="100 99 89 89" />
    </valueSampledData>
    <device>
        <reference value="Device/6ae8bff3-910a-419d-96f6-de0e8fd1d64d" />
    </device>
</Observation>
Observation
Observation.id[0]rdc-Observation-CGM-calibrated
Observation.meta[0].profile[0]https://roche.com/fhir/iop/StructureDefinition/rdc-Observation-CGM
Observation.extension[0].url[0]https://roche.com/fhir/iop/StructureDefinition/ext-CalibrationStatus
Observation.extension[0].value[0]calibrated
Observation.status[0]final
Observation.code[0].coding[0].system[0]http://snomed.info/sct
Observation.code[0].coding[0].code[0]434910001
Observation.code[0].coding[0].display[0]Interstitial fluid glucose concentration (observable entity)
Observation.subject[0].reference[0]Patient/34605fdc-74aa-4587-a5f0-92e6c5f64527
Observation.effective[0].start[0]2020-10-14T02:01:00+01:00
Observation.effective[0].end[0]2020-10-14T02:04:00+01:00
Observation.value[0].extension[0].url[0]https://roche.com/fhir/iop/StructureDefinition/ext-SampledDataTimestamps
Observation.value[0].extension[0].value[0]2020-10-14T02:01:00+01:00 2020-10-14T02:02:00+01:00 2020-10-14T02:03:00+01:00 2020-10-14T02:04:00+01:00
Observation.value[0].extension[1].url[0]https://roche.com/fhir/iop/StructureDefinition/ext-CGMFlags
Observation.value[0].extension[1].value[0]HI; X; X; LO
Observation.value[0].origin[0].value[0]0
Observation.value[0].origin[0].unit[0]mg/dL
Observation.value[0].origin[0].system[0]http://unitsofmeasure.org
Observation.value[0].origin[0].code[0]mg/dL
Observation.value[0].interval[0]60000
Observation.value[0].intervalUnit[0]ms
Observation.value[0].dimensions[0]1
Observation.value[0].data[0]100 99 89 89
Observation.device[0].reference[0]Device/6ae8bff3-910a-419d-96f6-de0e8fd1d64d

CGM Calibration status

The CGM value in the observation resource will be considered when extension: calibration-status = calibrated [Refer Example above]

if the extension: calibration-status = uncalibrated then it will be not considered as a valid entry, below is the calibration status representation for the same.

    {
        "url": "https://roche.com/fhir/iop/StructureDefinition/ext-CalibrationStatus",
        "valueString": "uncalibrated"    
    }

CGM Flags

The CGM Flags are values that denotes certain conditions like if the value is High or low for the CGM values measured, If the CGM values have any flags it will be marked in the CGM Flags extension, if there are no flags for a particular value it is denoted with X as shown in below sample.

So in the below valueSampledDate example below the data values have these flags HI; X; X; LO associated:

  • 100 -> HI is the flag associated
  • 99 -> X is represented stating no flag association
  • 89 -> LO & CALIBRATION REQUIRED (multiple flags are associated to single CGM value)
  • 89 -> LO is the flag associated
"valueSampledData": {
    "origin": {
        "value": 0,
        "unit": "mg/dL",
        "system": "http://unitsofmeasure.org",
        "code": "mg/dL"
    },
    "interval": "60000", // Time interval of the data
    "intervalUnits": "ms" // Time interval unit
    "dimensions": "1", // Hardcorded value in FHIR
    "data": "100 99 89 89", // CGM data values
    "extension": [
        {
            "url": "https://roche.com/fhir/iop/StructureDefinition/ext-SampledDataTimestamps",
            "valueString": "2020-10-14T02:01:00+01:00 2020-10-14T02:02:00+01:00 2020-10-14T02:03:00+01:00 2020-10-14T02:04:00+01:00"
        },
        {
            "url": "https://roche.com/fhir/iop/StructureDefinition/ext-CGMFlags",
            "valueString": "HI; X; X; LO"
        }
    ]
}

Notes

  1. CGM Device resource needs to be send first.
  2. Once the Device resource in place, CGM Data resource can be shared as it has a reference to the Device (CGM) resource.