<status value="draft"/> <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 handling of the variable in statistical analysis for exposures or outcomes (E.g. Dichotomous, Continuous, Descriptive)."/> <caseSensitive value="true"/> <valueSet value="http://hl7.org/fhir/ValueSet/variable-handling"/> <content value="complete"/> <concept> <code value="continuous"/> <display value="continuous variable"/> <definition value="A continuous variable is one for which, within the limits the variable ranges, any value is possible (from STATO http://purl.obolibrary.org/obo/STATO_0000251)."/> </concept> <concept> <code value="dichotomous"/> <display value="dichotomous variable"/> <definition value="A dichotomous variable is a categorical variable which is defined to have only 2 categories or possible values (from STATO http://purl.obolibrary.org/obo/STATO_0000090)."/> </concept> <concept> <code value="ordinal"/> <display value="ordinal variable"/> <definition value="An ordinal variable is a categorical variable where the discrete possible values are ordered or correspond to an implicit ranking (from STATO http://purl.obolibrary.org/obo/STATO_0000228)."/> </concept> <concept> <code value="polychotomous"/> <display value="polychotomous variable"/> <definition value="A polychotomous variable is a categorical variable which is defined to have minimally 2 categories or possible values. (from STATO http://purl.obolibrary.org/obo/STATO_0000087). Suggestion to limit code use to situations when neither dichotomous nor ordinal variables apply."/> </concept> </CodeSystem>

This code system http://hl7.org/fhir/variable-handling defines the following codes:

Code	Display	Definition
continuous	continuous variable	A continuous variable is one for which, within the limits the variable ranges, any value is possible (from STATO http://purl.obolibrary.org/obo/STATO_0000251).
dichotomous	dichotomous variable	A dichotomous variable is a categorical variable which is defined to have only 2 categories or possible values (from STATO http://purl.obolibrary.org/obo/STATO_0000090).
ordinal	ordinal variable	An ordinal variable is a categorical variable where the discrete possible values are ordered or correspond to an implicit ranking (from STATO http://purl.obolibrary.org/obo/STATO_0000228).
polychotomous	polychotomous variable	A polychotomous variable is a categorical variable which is defined to have minimally 2 categories or possible values. (from STATO http://purl.obolibrary.org/obo/STATO_0000087). Suggestion to limit code use to situations when neither dichotomous nor ordinal variables apply.