This code system http://hl7.org/fhir/research-study-arm-type defines the following codes:

Code Display
active-comparator Active Comparator
placebo-comparator Placebo Comparator
sham-comparator Sham Comparator
no-intervention No Intervention
experimental Experimental
other-arm-type Other Arm Type
<status value="active"/> <experimental value="false"/> <date value="2022-05-15T16:55:11.085+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="Codes for the main intent of the study."/> <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/research-study-arm-type"/> <content value="complete"/> <concept> <code value="active-comparator"/> <display value="Active Comparator"/> </concept> <concept> <code value="placebo-comparator"/> <display value="Placebo Comparator"/> </concept> <concept> <code value="sham-comparator"/> <display value="Sham Comparator"/> </concept> <concept> <code value="no-intervention"/> <display value="No Intervention"/> </concept> <concept> <code value="experimental"/> <display value="Experimental"/> </concept> <concept> <code value="other-arm-type"/> <display value="Other Arm Type"/> </concept> </CodeSystem>