This code system http://hl7.org/fhir/condition-questionnaire-purpose defines the following codes:

Code Display Definition
preadmit Pre-admit A pre-admit questionnaire.
diff-diagnosis Diff Diagnosis A questionnaire that helps with diferential diagnosis.
outcome Outcome A questionnaire to check on outcomes for the patient.
<status value="active"/> <experimental value="false"/> <date value="2021-01-05T10:01:24+11:00"/> <publisher value="HL7 (FHIR Project)"/> <contact> <telecom> <system value="url"/> <value value="http://hl7.org/fhir"/> </telecom> <telecom> <system value="email"/> <value value="fhir@lists.hl7.org"/> </telecom> </contact> <description value="The use of a questionnaire."/> <jurisdiction> <coding> <system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/> <code value="001"/> <display value="World"/> </coding> </jurisdiction> <caseSensitive value="true"/> <valueSet value="http://hl7.org/fhir/ValueSet/condition-questionnaire-purpose"/> <content value="complete"/> <concept> <code value="preadmit"/> <display value="Pre-admit"/> <definition value="A pre-admit questionnaire."/> </concept> <concept> <code value="diff-diagnosis"/> <display value="Diff Diagnosis"/> <definition value="A questionnaire that helps with diferential diagnosis."/> </concept> <concept> <code value="outcome"/> <display value="Outcome"/> <definition value="A questionnaire to check on outcomes for the patient."/> </concept> </CodeSystem>