define "SDE Sex":
  case
    when Patient.gender = 'male' then Code { code: 'M', system: 'http://hl7.org/fhir/v3/AdministrativeGender', display: 'Male' }
    when Patient.gender = 'female' then Code { code: 'F', system: 'http://hl7.org/fhir/v3/AdministrativeGender', display: 'Female' }
    else null
  end

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

define "Stratifier 3" :
  "Inpatient Encounter" Encounter
    where PrincipalDiagnosis(Encounter) is null

define "Stratifier 4" :
  "Inpatient Encounter" Encounter
    where PrincipalDiagnosis(Encounter) is null

define "SDE Payer":
    [Coverage: type in "Payer"] Payer
      return {
        code: Payer.type,
        period: Payer.period
      }

define "Initial Population" :
  "Inpatient Encounter" Encounter

define "SDE Ethnicity":
  (flatten (
    Patient.extension Extension
      where Extension.url = 'http://hl7.org/fhir/us/core/StructureDefinition/us-core-ethnicity'
        return Extension.extension
  )) E
    where E.url = 'ombCategory'
      or E.url = 'detailed'
    return E.value as Coding

define "SDE Race":
  (flatten (
    Patient.extension Extension
      where Extension.url = 'http://hl7.org/fhir/us/core/StructureDefinition/us-core-race'
        return Extension.extension
  )) E
    where E.url = 'ombCategory'
      or E.url = 'detailed'
    return E.value as Coding

define "Stratifier 1" :
  "Inpatient Encounter" Encounter
    where not (PrincipalDiagnosis(Encounter).code in "Psychiatric/Mental Health Patient")

define "Stratifier 2" :
  "Inpatient Encounter" Encounter
    where PrincipalDiagnosis(Encounter).code in "Psychiatric/Mental Health Patient"