I tried to create a patient for FHIR version of CMS104 (21F5386A-AC56-4C4F-98A7-476B5078E626) that meets IPOP

I  set birthdate to 12/02/1990 so age is >= 18

Added Encounter: Non-Elective Inpatient Encounter

Note that the PrincipalDiagnosis() function does a retrieve of a Condition resource.

I wanted to add a Condition resource and then have the Encounter.diagnosis.condition reference it, but
1. There was no way to add the Condition resource (not given the option)
2. I tried to use Procedure as an alternative to reference (allowed by QI-Core [1]).  I added  Procedure: Comfort Measures (Under Clinical Summary heading) but I could not see a way to add the reference in Encounter.diagnosis.condition

Not clear why Bonnie had Procedure Comfort Measures as an option; the logic never uses "Procedure".

[1] http://hl7.org/fhir/us/qicore/STU4/StructureDefinition-qicore-encounter.html

See relevant CQL logic below

define "Initial Population":
TJC."Encounter with Principal Diagnosis and Age"}}
 {{define "Encounter with Principal Diagnosis and Age":
"All Stroke Encounter" AllStrokeEncounter
with ["Patient"] BirthDate
such that Global."CalendarAgeInYearsAt"(FHIRHelpers.ToDate(BirthDate.birthDate), start of FHIRHelpers.ToInterval(AllStrokeEncounter.period)) >= 18

define "All Stroke Encounter": "Non Elective Inpatient Encounter" NonElectiveEncounter*where* Global.PrincipalDiagnosis(NonElectiveEncounter).code in "Hemorrhagic Stroke" or Global.PrincipalDiagnosis(NonElectiveEncounter).code in "Ischemic Stroke"

define "Non Elective Inpatient Encounter":
["Encounter": "Non-Elective Inpatient Encounter"] NonElectiveEncounter
where Global."LengthInDays"(NonElectiveEncounter.period) <= 120
and NonElectiveEncounter.period ends during "Measurement Period"

 {{define function "PrincipalDiagnosis"(Encounter Encounter ):
(singleton from (Encounter.diagnosis D where FHIRHelpers.ToInteger(D.rank) = 1)) PD
return singleton from ([Condition] C where C.id = "GetId"(PD.condition.reference))}}
 )