diff --git a/structuredefinitions/UKCore-Observation-VitalSigns.xml b/structuredefinitions/UKCore-Observation-VitalSigns.xml
index aebfc715..5df6b055 100644
--- a/structuredefinitions/UKCore-Observation-VitalSigns.xml
+++ b/structuredefinitions/UKCore-Observation-VitalSigns.xml
@@ -57,37 +57,6 @@
   <baseDefinition value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Observation" />
   <derivation value="constraint" />
   <differential>
-    <element id="Observation.identifier.assigner.identifier.assigner">
-      <path value="Observation.identifier.assigner.identifier.assigner" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Organization" />
-      </type>
-    </element>
-    <element id="Observation.basedOn">
-      <path value="Observation.basedOn" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/DeviceRequest" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ImmunizationRecommendation" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/NutritionOrder" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-CarePlan" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-MedicationRequest" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-ServiceRequest" />
-      </type>
-    </element>
-    <element id="Observation.partOf">
-      <path value="Observation.partOf" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/MedicationAdministration" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ImagingStudy" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Procedure" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-MedicationDispense" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-MedicationStatement" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Immunization" />
-      </type>
-    </element>
     <element id="Observation.code.coding:snomedCT">
       <path value="Observation.code.coding" />
       <sliceName value="snomedCT" />
@@ -108,18 +77,6 @@
         <valueSet value="http://hl7.org/fhir/ValueSet/observation-vitalsignresult" />
       </binding>
     </element>
-    <element id="Observation.performer">
-      <path value="Observation.performer" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Organization" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Patient" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Practitioner" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-PractitionerRole" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-RelatedPerson" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-CareTeam" />
-      </type>
-    </element>
     <element id="Observation.value[x]">
       <path value="Observation.value[x]" />
       <binding>
@@ -146,18 +103,11 @@
       <path value="Observation.bodySite.coding.display" />
       <min value="1" />
     </element>
-    <element id="Observation.specimen">
-      <path value="Observation.specimen" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Specimen" />
-      </type>
-    </element>
     <element id="Observation.hasMember">
       <path value="Observation.hasMember" />
       <type>
         <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/QuestionnaireResponse" />
+        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-QuestionnaireResponse" />
         <targetProfile value="http://hl7.org/fhir/StructureDefinition/MolecularSequence" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Observation-VitalSigns" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Observation" />
@@ -167,9 +117,9 @@
       <path value="Observation.derivedFrom" />
       <type>
         <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ImagingStudy" />
+        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-ImagingStudy" />
         <targetProfile value="http://hl7.org/fhir/StructureDefinition/Media" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/QuestionnaireResponse" />
+        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-QuestionnaireResponse" />
         <targetProfile value="http://hl7.org/fhir/StructureDefinition/MolecularSequence" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Observation-VitalSigns" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-DocumentReference" />
diff --git a/structuredefinitions/UKCore-VitalSigns-Observation.xml b/structuredefinitions/UKCore-VitalSigns-Observation.xml
index 62f493af..ab42ceb1 100644
--- a/structuredefinitions/UKCore-VitalSigns-Observation.xml
+++ b/structuredefinitions/UKCore-VitalSigns-Observation.xml
@@ -57,37 +57,6 @@
   <baseDefinition value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Observation" />
   <derivation value="constraint" />
   <differential>
-    <element id="Observation.identifier.assigner.identifier.assigner">
-      <path value="Observation.identifier.assigner.identifier.assigner" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Organization" />
-      </type>
-    </element>
-    <element id="Observation.basedOn">
-      <path value="Observation.basedOn" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/DeviceRequest" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ImmunizationRecommendation" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/NutritionOrder" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-CarePlan" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-MedicationRequest" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-ServiceRequest" />
-      </type>
-    </element>
-    <element id="Observation.partOf">
-      <path value="Observation.partOf" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/MedicationAdministration" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ImagingStudy" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Procedure" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-MedicationDispense" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-MedicationStatement" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Immunization" />
-      </type>
-    </element>
     <element id="Observation.code.coding:snomedCT">
       <path value="Observation.code.coding" />
       <sliceName value="snomedCT" />
@@ -108,18 +77,6 @@
         <valueSet value="http://hl7.org/fhir/ValueSet/observation-vitalsignresult" />
       </binding>
     </element>
-    <element id="Observation.performer">
-      <path value="Observation.performer" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Organization" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Patient" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Practitioner" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-PractitionerRole" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-RelatedPerson" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-CareTeam" />
-      </type>
-    </element>
     <element id="Observation.value[x]">
       <path value="Observation.value[x]" />
       <binding>
@@ -146,18 +103,11 @@
       <path value="Observation.bodySite.coding.display" />
       <min value="1" />
     </element>
-    <element id="Observation.specimen">
-      <path value="Observation.specimen" />
-      <type>
-        <code value="Reference" />
-        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Specimen" />
-      </type>
-    </element>
     <element id="Observation.hasMember">
       <path value="Observation.hasMember" />
       <type>
         <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/QuestionnaireResponse" />
+        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-QuestionnaireResponse" />
         <targetProfile value="http://hl7.org/fhir/StructureDefinition/MolecularSequence" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-VitalSigns-Observation" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-Observation" />
@@ -167,9 +117,9 @@
       <path value="Observation.derivedFrom" />
       <type>
         <code value="Reference" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/ImagingStudy" />
+        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-ImagingStudy" />
         <targetProfile value="http://hl7.org/fhir/StructureDefinition/Media" />
-        <targetProfile value="http://hl7.org/fhir/StructureDefinition/QuestionnaireResponse" />
+        <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-QuestionnaireResponse" />
         <targetProfile value="http://hl7.org/fhir/StructureDefinition/MolecularSequence" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-VitalSigns-Observation" />
         <targetProfile value="https://fhir.hl7.org.uk/StructureDefinition/UKCore-DocumentReference" />