<status value="draft"/> <publisher value="HL7 International / Clinical Decision Support"/> <contact> <telecom> <system value="url"/> <value value="http://www.hl7.org/Special/committees/dss"/> </telecom> </contact> <description value="Placebo"/> <actual value="true"/> <definition> <concept> <coding> <system value="http://snomed.info/sct"/> <code value="182886004"/> <display value="Placebo given (situation)"/> </coding> </concept> </definition> <handling/> </EvidenceVariable>

In a study of response rates if placebo is given, "placcebo given" may be the variable for the exposure of interest.