The EvidenceVariable resource describes a "PICO" element that knowledge (evidence, assertion, recommendation) is about.

EvidenceVariable
url
Canonical identifier for this evidence variable, represented as a URI (globally unique)
identifier
Additional identifier for the evidence variable
version
Business version of the evidence variable
name
Name for this evidence variable (computer friendly)
title
Name for this evidence variable (human friendly)
shortTitle
Title for use in informal contexts
subtitle
Subordinate title of the EvidenceVariable
status
draft | active | retired | unknown
date
Date last changed
publisher
Name of the publisher (organization or individual)
contact
Contact details for the publisher
description
Natural language description of the evidence variable
note
Used for footnotes or explanatory notes
useContext
The context that the content is intended to support
jurisdiction
Intended jurisdiction for evidence variable (if applicable)
approvalDate
When the evidence variable was approved by publisher
lastReviewDate
When the evidence variable was last reviewed
effectivePeriod
When the evidence variable is expected to be used
topic
The category of the EvidenceVariable, such as Education, Treatment, Assessment, etc.
author
Who authored the content
editor
Who edited the content
reviewer
Who reviewed the content
endorser
Who endorsed the content
relatedArtifact
Additional documentation, citations, etc.
type
dichotomous | continuous | descriptive
characteristic
What defines the members of the evidence element
description
Natural language description of the characteristic
definition[x]
What code or expression defines members?
usageContext
What code/value pairs define members?
exclude
Whether the characteristic includes or excludes members
participantEffective[x]
What time period do participants cover
timeFromStart
Observation time from study start
groupMeasure
mean | median | mean-of-mean | mean-of-median | median-of-mean | median-of-median