define "Initial Population":
  "Encounter With Hypoglycemic Medication Administration"

define "Denominator":
  "Initial Population"

define "Numerator":
  "Encounter With Severe Hypoglycemic Harm Event"

define "SDE Sex":
  case
    when Patient.sex = '248153007' then "Male (finding)"
    when Patient.sex = '248152002' then "Female (finding)"
    else null
  end

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

define "SDE Ethnicity":
  Patient.ethnicity E
    return Tuple {
      codes: { E.ombCategory } union E.detailed,
      display: E.text
    }

define "SDE Race":
  Patient.race R
    return Tuple {
      codes: R.ombCategory union R.detailed,
      display: R.text
    }

define "SDE Sex":
  SDE."SDE Sex"

define "Qualifying Encounter":
  ["Encounter": "Encounter Inpatient"] InpatientEncounter
    where AgeInYearsAt(date from start of InpatientEncounter.period) >= 18
      and InpatientEncounter.period ends during day of "Measurement Period"
      and InpatientEncounter.status = 'finished'

define "Hypoglycemic Medication Administration":
  ["MedicationAdministration": "Hypoglycemics Severe Hypoglycemia"] HypoMedication
    where HypoMedication.status = 'completed'

define "Encounter With Hypoglycemic Medication Administration":
  "Qualifying Encounter" InpatientHospitalization
    with "Hypoglycemic Medication Administration" HypoglycemicMedication
      such that HypoglycemicMedication.effective.toInterval ( ) starts during InpatientHospitalization.hospitalizationWithObservation ( )

define "Initial Population":
  "Encounter With Hypoglycemic Medication Administration"

define "Denominator":
  "Initial Population"

define "Glucose Test With Result Less Than 40":
  from
    "Denominator" InpatientHospitalization,
    "Hypoglycemic Medication Administration" HypoglycemicMedication,
    ["LaboratoryResultObservation": "Glucose Lab Test Mass Per Volume"] GlucoseTest
    let HospitalizationInterval: InpatientHospitalization.hospitalizationWithObservation ( ),
    HypoglycemicMedicationStart: HypoglycemicMedication.effective.toInterval ( ),
    GlucoseTestTime: GlucoseTest.effective.earliest ( )
    where GlucoseTestTime during HospitalizationInterval
      and GlucoseTest.status in { 'final', 'amended', 'corrected' }
      and GlucoseTest.value < 40 'mg/dL'
      and HypoglycemicMedicationStart starts 24 hours or less before or on GlucoseTestTime
    return GlucoseTest

define "Low Glucose Test Followed By Glucose Test Result Greater Than 80":
  from
    "Denominator" InpatientHospitalization,
    "Glucose Test With Result Less Than 40" LowGlucoseTest,
    ["LaboratoryResultObservation": "Glucose Lab Test Mass Per Volume"] FollowupGlucoseTest
    let GlucoseTestTime: LowGlucoseTest.effective.earliest ( ),
    FollowupGlucoseTestTime: FollowupGlucoseTest.effective.earliest ( )
    where FollowupGlucoseTestTime 5 minutes or less after GlucoseTestTime
      and GlucoseTestTime during InpatientHospitalization.hospitalizationWithObservation ( )
      and FollowupGlucoseTestTime during InpatientHospitalization.hospitalizationWithObservation ( )
      and FollowupGlucoseTest.id !~ LowGlucoseTest.id
      and FollowupGlucoseTest.status in { 'final', 'amended', 'corrected' }
      and FollowupGlucoseTest.value > 80 'mg/dL'
    return LowGlucoseTest

define "Severe Hypoglycemic Harm Event":
  "Glucose Test With Result Less Than 40" LowGlucoseTest
    where not ( LowGlucoseTest.id in "Low Glucose Test Followed By Glucose Test Result Greater Than 80".id )

define "Encounter With Severe Hypoglycemic Harm Event":
  from
    "Denominator" InpatientHospitalization,
    "Severe Hypoglycemic Harm Event" HypoglycemicEvent
    let GlucoseTestTime: HypoglycemicEvent.effective.earliest ( ),
    HospitalizationInterval: InpatientHospitalization.hospitalizationWithObservation ( )
    where GlucoseTestTime during HospitalizationInterval
    return InpatientHospitalization

define "Numerator":
  "Encounter With Severe Hypoglycemic Harm Event"

define "SDE Payer":
  SDE."SDE Payer"

define "SDE Ethnicity":
  SDE."SDE Ethnicity"

define "SDE Race":
  SDE."SDE Race"

/*
@description: Hospitalization with Observation returns the total interval from the start of any immediately prior emergency department visit through the observation visit to the discharge of the given encounter
*/
define fluent function hospitalizationWithObservation(TheEncounter Encounter ):
  TheEncounter Visit
  		let ObsVisit: Last([Encounter: "Observation Services"] LastObs
  				where LastObs.status = 'finished'
            and LastObs.period ends 1 hour or less on or before start of Visit.period
  				sort by end of period
  			),
  			VisitStart: Coalesce(start of ObsVisit.period, start of Visit.period),
  			EDVisit: Last([Encounter: "Emergency Department Visit"] LastED
  				where LastED.status = 'finished'
            and LastED.period ends 1 hour or less on or before VisitStart
  				sort by end of period
  			)
  		return Interval[Coalesce(start of EDVisit.period, VisitStart), end of Visit.period]

/*
@description: Given an interval, return the starting point if the interval has a starting boundary specified,
otherwise, return the ending point
*/
define fluent function earliest(choice Choice<DateTime, Quantity, Interval<DateTime>, Interval<Quantity>> ):
  (choice.toInterval()) period
    return
      if (period."hasStart"()) then start of period
      else end of period

/*
@description: Given an interval, return true if the interval has a starting boundary specified
(i.e. the start of the interval is not null and not the minimum DateTime value)
*/
define fluent function hasStart(period Interval<DateTime> ):
  not ( start of period is null
      or start of period = minimum DateTime
  )

define function ToString(value uri): value.value

/*
@description: Converts the given [Period](https://hl7.org/fhir/datatypes.html#Period)
value to a CQL DateTime Interval
@comment: If the start value of the given period is unspecified, the starting
boundary of the resulting interval will be open (meaning the start of the interval
is unknown, as opposed to interpreted as the beginning of time).
*/
define function ToInterval(period FHIR.Period):
    if period is null then
        null
    else
        if period."start" is null then
            Interval(period."start".value, period."end".value]
        else
            Interval[period."start".value, period."end".value]

/*
@description: Converts the given FHIR [Coding](https://hl7.org/fhir/datatypes.html#Coding) value to a CQL Code.
*/
define function ToCode(coding FHIR.Coding):
    if coding is null then
        null
    else
        System.Code {
          code: coding.code.value,
          system: coding.system.value,
          version: coding.version.value,
          display: coding.display.value
        }