{
  "resourceType": "Questionnaire",
  "status": "active",
  "item": [
    {
      "linkId": "body",
      "text": "Body Measurements",
      "type": "group",
      "item": [
        {
          "linkId": "body-height",
          "code": [
            {
              "system": "http://loinc.org",
              "code": "8302-2"
            }
          ],
          "text": "Height (cm)",
          "type": "decimal",
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-unit",
              "valueCoding": {
                "system": "http://unitsofmeasure.org",
                "code": "cm",
                "display": "cm"
              }
            }
          ]
        },
        {
          "linkId": "body-weight",
          "code": [
            {
              "system": "http://loinc.org",
              "code": "29463-7"
            }
          ],
          "text": "Weight (kg)",
          "type": "decimal",
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-unit",
              "valueCoding": {
                "system": "http://unitsofmeasure.org",
                "code": "kg",
                "display": "kg"
              }
            }
          ]
        },
        {
          "linkId": "body-sex",
          "code": [
            {
              "system": "http://loinc.org",
              "code": "76689-9"
            }
          ],
          "text": "Sex assigned at birth (used by the ideal body weight formula)",
          "type": "choice",
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-itemControl",
              "valueCodeableConcept": {
                "coding": [
                  {
                    "system": "http://hl7.org/fhir/questionnaire-item-control",
                    "code": "radio-button"
                  }
                ]
              }
            }
          ],
          "answerOption": [
            {
              "valueCoding": {
                "system": "http://loinc.org",
                "code": "LA3-6",
                "display": "Female"
              }
            },
            {
              "valueCoding": {
                "system": "http://loinc.org",
                "code": "LA2-8",
                "display": "Male"
              }
            }
          ]
        },
        {
          "linkId": "body-waist",
          "text": "Waist circumference (cm)",
          "type": "decimal",
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-unit",
              "valueCoding": {
                "system": "http://unitsofmeasure.org",
                "code": "cm",
                "display": "cm"
              }
            }
          ]
        },
        {
          "linkId": "body-hip",
          "text": "Hip circumference (cm)",
          "type": "decimal",
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-unit",
              "valueCoding": {
                "system": "http://unitsofmeasure.org",
                "code": "cm",
                "display": "cm"
              }
            }
          ]
        },
        {
          "linkId": "body-bmi",
          "code": [
            {
              "system": "http://loinc.org",
              "code": "39156-5"
            }
          ],
          "text": "Body mass index (kg/m²)",
          "type": "decimal",
          "readOnly": true,
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-unit",
              "valueCoding": {
                "system": "http://unitsofmeasure.org",
                "code": "kg/m2",
                "display": "kg/m²"
              }
            },
            {
              "url": "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression",
              "valueExpression": {
                "language": "text/fhirpath",
                "expression": "((%resource.item.where(linkId='body').item.where(linkId='body-weight').answer.valueDecimal) / ((%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100) * (%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100))).round(1)"
              }
            }
          ]
        },
        {
          "linkId": "body-bmi-category",
          "text": "BMI category (WHO)",
          "type": "string",
          "readOnly": true,
          "extension": [
            {
              "url": "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression",
              "valueExpression": {
                "language": "text/fhirpath",
                "expression": "iif(((%resource.item.where(linkId='body').item.where(linkId='body-weight').answer.valueDecimal) / ((%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100) * (%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100))).exists(), iif(((%resource.item.where(linkId='body').item.where(linkId='body-weight').answer.valueDecimal) / ((%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100) * (%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100))) < 18.5, 'Underweight', iif(((%resource.item.where(linkId='body').item.where(linkId='body-weight').answer.valueDecimal) / ((%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100) * (%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100))) < 25, 'Normal weight', iif(((%resource.item.where(linkId='body').item.where(linkId='body-weight').answer.valueDecimal) / ((%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100) * (%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 100))) < 30, 'Overweight', 'Obese'))), {})"
              }
            }
          ]
        },
        {
          "linkId": "body-bsa",
          "code": [
            {
              "system": "http://loinc.org",
              "code": "8277-6"
            }
          ],
          "text": "Body surface area (m², Mosteller)",
          "type": "decimal",
          "readOnly": true,
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-unit",
              "valueCoding": {
                "system": "http://unitsofmeasure.org",
                "code": "m2",
                "display": "m²"
              }
            },
            {
              "url": "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression",
              "valueExpression": {
                "language": "text/fhirpath",
                "expression": "(((%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal) * (%resource.item.where(linkId='body').item.where(linkId='body-weight').answer.valueDecimal)) / 3600).sqrt().round(2)"
              }
            }
          ]
        },
        {
          "linkId": "body-ibw",
          "text": "Ideal body weight (kg, Devine)",
          "type": "decimal",
          "readOnly": true,
          "extension": [
            {
              "url": "http://hl7.org/fhir/StructureDefinition/questionnaire-unit",
              "valueCoding": {
                "system": "http://unitsofmeasure.org",
                "code": "kg",
                "display": "kg"
              }
            },
            {
              "url": "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression",
              "valueExpression": {
                "language": "text/fhirpath",
                "expression": "iif((%resource.item.where(linkId='body').item.where(linkId='body-sex').answer.valueCoding.code).exists(), (iif((%resource.item.where(linkId='body').item.where(linkId='body-sex').answer.valueCoding.code) = 'LA3-6', 45.5, 50) + (2.3 * ((%resource.item.where(linkId='body').item.where(linkId='body-height').answer.valueDecimal / 2.54) - 60))).round(1), {})"
              }
            }
          ]
        },
        {
          "linkId": "body-whr",
          "text": "Waist-to-hip ratio",
          "type": "decimal",
          "readOnly": true,
          "extension": [
            {
              "url": "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression",
              "valueExpression": {
                "language": "text/fhirpath",
                "expression": "((%resource.item.where(linkId='body').item.where(linkId='body-waist').answer.valueDecimal) / (%resource.item.where(linkId='body').item.where(linkId='body-hip').answer.valueDecimal)).round(2)"
              }
            }
          ]
        }
      ]
    }
  ]
}