This value set includes codes based on the following rules:

• Include these codes as defined in http://snomed.info/sct version http://snomed.info/sct/731000124108/version/20200901

  Code	Display
  10828004	Yes, positive
  260385009	Yes, negative
  373121007	No test

• Include these codes as defined in urn:oid:2.16.840.1.114222.4.5.274 version 20200526

  Code	Display
  PHC1286	No lesions and no tissue to test

• Include these codes as defined in http://terminology.hl7.org/CodeSystem/v3-NullFlavor version 20090501

  Code	Display
  UNK	Unknown