{
    "resourceType": "Observation",
    "id": "Observation-Cellularity-Example",
    "status": "final",
    "code": {
        "text": "Cellularity"
    },
    "subject": {
        "reference": "Patient/Patient-ZelmaHadjkiss-Example",
        "identifier": {
            "system": "https://fhir.nhs.uk/Id/nhs-number",
            "value": "9449307555"
        }
    },
    "specimen": {
        "identifier": {
            "system": "https://fhir.add.nhs.uk/Id/specimenId",
            "value": "RA257630"
        }
    },
    "interpretation":  [
        {
            "coding":  [
                {
                    "system": "http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation",
                    "code": "H",
                    "display": "High"
                }
            ]
        }
    ],
    "effectiveDateTime": "2023-09-08T10:00:00Z"
}

<Observation xmlns="http://hl7.org/fhir">
    <id value="Observation-Cellularity-Example" />
    <status value="final" />
    <code>
        <text value="Cellularity" />
    </code>
    <subject>
        <reference value="Patient/Patient-ZelmaHadjkiss-Example" />
        <identifier>
            <system value="https://fhir.nhs.uk/Id/nhs-number" />
            <value value="9449307555" />
        </identifier>
    </subject>
    <effectiveDateTime value="2023-09-08T10:00:00Z" />
    <interpretation>
        <coding>
            <system value="http://terminology.hl7.org/CodeSystem/v3-ObservationInterpretation" />
            <code value="H" />
            <display value="High" />
        </coding>
    </interpretation>
    <specimen>
        <identifier>
            <system value="https://fhir.add.nhs.uk/Id/specimenId" />
            <value value="RA257630" />
        </identifier>
    </specimen>
</Observation>

Propose a change to Observation-Cellularity-Example