Heart Failure (HF): Angiotensin-Converting Enzyme (ACE) Inhibitor or Angiotensin Receptor Blocker (ARB) or Angiotensin Receptor-Neprilysin Inhibitor (ARNI) Therapy for Left Ventricular Systolic Dysfunction (LVSD)FHIR - Draft dQM CMS Content Implementation Guide v2025.1.0

Draft dQM CMS Content Implementation Guide, published by cqframework. This guide is not an authorized publication; it is the continuous build for version 2025.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/cqframework/dqm-content-cms-2025/ and changes regularly. See the Directory of published versions

Measure: Heart Failure (HF): Angiotensin-Converting Enzyme (ACE) Inhibitor or Angiotensin Receptor Blocker (ARB) or Angiotensin Receptor-Neprilysin Inhibitor (ARNI) Therapy for Left Ventricular Systolic Dysfunction (LVSD)FHIR

Official URL: https://madie.cms.gov/Measure/CMS135FHIRACEIorARBorARNIforHF		Version: 1.1.000
Active as of 2026-01-16	Responsible: American Heart Association	Computable Name: CMS135FHIRACEIorARBorARNIforHF
Other Identifiers: Short Name: CMS135FHIR (use: usual, ), UUID:86136d6c-dbe1-4b7f-89f3-406cb90f08d5 (use: official, ), UUID:a0aa7f51-9882-4ceb-b4e5-bb94669b62ca (use: official, ), Endorser: 0081e (use: official, ), Publisher: 135FHIR (use: official, )
Copyright/Legal: Copyright 2025 American College of Cardiology and American Heart Association. All Rights Reserved.

Percentage of patients aged 18 years and older with a diagnosis of heart failure (HF) with a current or prior left ventricular ejection fraction (LVEF) <=40% who were prescribed or already taking ACE inhibitor or ARB or ARNI therapy during the measurement period

Metadata

Title Heart Failure (HF): Angiotensin-Converting Enzyme (ACE) Inhibitor or Angiotensin Receptor Blocker (ARB) or Angiotensin Receptor-Neprilysin Inhibitor (ARNI) Therapy for Left Ventricular Systolic Dysfunction (LVSD)FHIR

Version 1.1.000

Short Name CMS135FHIR

GUID (Version Independent) urn:uuid:86136d6c-dbe1-4b7f-89f3-406cb90f08d5

GUID (Version Specific) urn:uuid:a0aa7f51-9882-4ceb-b4e5-bb94669b62ca

CMS Identifier 135FHIR

CMS Consensus Based Entity Identifier 0081e

Effective Period 2026-01-01 through 2026-12-31

Steward (Publisher) American Heart Association

Developer American Heart Association

Developer American Medical Association (AMA)

Description

Disclaimer

The Measure is not a clinical guideline, does not establish a standard of medical care, and has not been tested for all potential applications.

The Measure, while copyrighted, can be reproduced and distributed, without modification, for noncommercial purposes, e.g., use by health care providers in connection with their practices. Commercial use is defined as the sale, license, or distribution of the Measure for commercial gain, or incorporation of the Measure into a product or service that is sold, licensed or distributed for commercial gain.

Commercial uses of the Measure require a license agreement between the user and the American College of Cardiology (ACC) or the American Heart Association (AHA). Neither the ACC, nor AHA, nor their members shall be responsible for any use of the Measure.

ACC and AHA encourage use of the Measure by other health care professionals, where appropriate. THE MEASURE AND SPECIFICATIONS ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.

Limited proprietary coding is contained in the Measure specifications for convenience. Users of the proprietary code sets should obtain all necessary licenses from the owners of these code sets. The ACC and AHA and their members disclaim all liability for use or accuracy of any Current Procedural Terminology (CPT[R]) or other coding contained in the specifications.

CPT(R) contained in the Measure specifications is copyright 2004-20234 American Medical Association. LOINC(R) is copyright 2004-20234 Regenstrief Institute, Inc. This material contains SNOMED Clinical Terms(R) (SNOMED CT[R]) copyright 2004-20234 International Health Terminology Standards Development Organisation. ICD-10 is copyright 20234 World Health Organization. All Rights Reserved.

The American Medical Association's and the PCPI(R) Foundation's significant past efforts and contributions to the performance measure are gratefully acknowledged. Due to technical limitations, registered trademarks are indicated by (R) or [R].

Rationale

Use of ACE inhibitor, ARB, or ARNI therapy has been associated with improved outcomes in patients with reduced LVEF. Long-term therapy with ARBs have also been shown to reduce morbidity and mortality, especially in ACE inhibitor--intolerant patients. More recently, ARNI therapy has also been shown to more significantly improve outcomes, such that the newest guidelines recommend replacement of ACE inhibitors or ARBs with ARNI therapy in eligible patients. However, despite the benefits of these drugs, use of ACE inhibitor, ARB, or ARNI remains suboptimal.

Clinical Recommendation Statement

In patients with Heart Failure with Reduced Ejection Fraction (HFrEF) and New York Heart Association (NYHA) class II to III symptoms, the use of ARNI is recommended to reduce morbidity and mortality (Class I, Level of Evidence A) (Heidenreich et al., 2022). In patients with previous or current symptoms of chronic HFrEF, the use of angiotension-converting enzyme inhibitors (ACEi) is beneficial to reduce morbidity and mortality when the use of ARNI is not feasible (Class I, Level of Evidence A) (Heidenreich et al., 2022). In patients with previous or current symptoms of chronic HFrEF who are intolerant to ACEi because of cough or angioedema and when the use of ARNI is not feasible, the use of ARB is recommended to reduce morbidity and mortality (Class I, Level of Evidence A) (Heidenreich et al., 2022). In patients with chronic symptomatic HFrEF NYHA class II or III who tolerate an ACEi or ARB, replacement by an ARNI is recommended to further reduce morbidity and mortality (Class I, Level of Evidence B-R) (Heidenreich et al., 2022). ARNI should not be administered concomitantly with ACEi or within 36 hours of the last dose of an ACEi (Class II: Harm, Level of Evidence B-R) (Heidenreich et al., 2022). ARNI should not be administered to patients with any history of angioedema (Class III: Harm, Level of Evidence C-LD) (Heidenreich et al., 2022). ACEi should not be administered to patients with any history of angioedema (Class III: Harm, Level of Evidence C-LD) (Heidenreich et al., 2022).

Drugs Commonly Used for Stage C HFrEF (abbreviated to align with focus of measure to include only ACE inhibitors, ARB and ARNI therapy)

Drug

Initial Daily Dose(s)

Target Dose(s)

Mean Doses Achieved in Clinical Trials

ACEi

Captopril

6.25 mg 3 times

50 mg 3 times

122.7 mg total daily

Enalapril

2.5 mg twice

10 to 20 mg twice

16.6 mg total daily

Fosinopril

5 to 10 mg once

40 mg once

N/A

Lisinopril

2.5 to 5 mg once

20 to 40 mg once

32.5 to 35.0 mg total daily

Perindopril

2 mg once

8 to 16 mg once

N/A

Quinapril

5 mg twice

20 mg twice

N/A

Ramipril

1.25 to 2.5 mg once

10 mg once

N/A

Trandolapril

1 mg once

4 mg once

N/A

ARB

Candesartan

4 to 8 mg once

32 mg once

24 mg total daily

Losartan

25 to 50 mg once

50 to 150 mg once

129 mg total daily

Valsartan

20 to 40 mg twice

160 mg twice

254 mg total daily

ARNI

Sacubitril-valsartan

49/51 mg twice (sacubitril/valsartan)

97/103 mg twice (sacubitril/valsartan)

182/193 mg (sacubitril/valsartan) total daily (therapy may be initiated at 24/26 mg twice)

Citation

Heidenreich, P.A., Bozkurt, B, Aguilar, D., ... Allen, L. A. (2022). 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure A report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation, 145(18), e895-e1032. doi: 10.1161/CIR.0000000000001063

Definition Moderate or Severe LVSD: LVEF \<=40% corresponds to qualitative documentation of moderate dysfunction or severe dysfunction (LVSD). The LVSD may be determined by quantitative or qualitative assessment, which may be current or historical. Examples of a quantitative or qualitative assessment may include an echocardiogram: 1. that provides a numerical value of LVSD or 2. that uses descriptive terms such as moderately or severely depressed left ventricular systolic function. Any current or prior ejection fraction study documenting LVSD can be used to identify patients.

Definition Prescribed: Denotes that a prescription has been given to the patient for ACE inhibitor or ARB or ARNI therapy at one or more visits in the measurement period OR that the patient is already taking an ACE inhibitor or ARB or ARNI therapy as documented in their current medication list

Guidance (Usage) This eCQM is to be reported as patient-based. To satisfy this measure, it must be reported for all heart failure patients at least once during the measurement period. The requirement of two or more visits is used to establish that the eligible clinician has an existing relationship with the patient. A range value should satisfy the logic requirement for 'Ejection Fraction' as long as the ranged observation value clearly meets the less than or equal to 40% threshold noted in the denominator logic. A range that is greater than 40% would not meet the measure requirement. In order for the Ejection Fraction result pathway to be recognized as below 40%, the result must be reported as a number with unit of %. A text string of "below 40%" or "ejection fraction between 35 and 40%" will not be recognized through electronic data capture. Although, this criteria can also be met using the Diagnosis pathway if specified as "Moderate or Severe." Eligible clinicians who have given a prescription for or whose patient is already taking an Angiotensin-Converting Enzyme Inhibitor (ACEI) or Angiotensin Receptor Blocker (ARB) would meet performance for this measure. Other combination therapies that consist of an ACEI plus diuretic, ARB + neprilysin inhibitor (ARNI), ARB plus diuretic, ACEI plus calcium channel blocker, ARB plus calcium channel blocker, or ARB plus calcium channel blocker plus diuretic would also meet performance for this measure. This FHIR-based measure has been derived from the QDM-based measure CMS135v14. Please refer to the HL7 QI-Core Implementation Guide (https://hl7.org/fhir/us/qicore/STU6/) for more information on QI-Core and mapping recommendations from QDM to QI-Core STU 6 (https://hl7.org/fhir/us/qicore/STU6/qdm-to-qicore.html).

Measure Group (Rate) (ID: Group_1)

Basis boolean

Scoring Proportion

Improvement Notation Increased score indicates improvement

Type Process

Initial Population

ID: InitialPopulation_1
Description:

All patients aged 18 years and older with two qualifying encounters during the measurement period and a diagnosis of heart failure on or before at least one qualifying encounter

Criteria: Initial Population

Denominator

ID: Denominator_1
Description:

Equals Initial Population with a current or prior LVEF \<= 40%

Criteria: Denominator

Denominator Exclusion

ID: DenominatorExclusion_1
Description:

Patients with a history of heart transplant or with a Left Ventricular Assist Device (LVAD) prior to the end of the outpatient encounter with Moderate or Severe LVSD

Criteria: Denominator Exclusions

Denominator Exception

ID: DenominatorException_1
Description:

* Documentation of medical reason(s) for not prescribing ACE inhibitor or ARB or ARNI therapy (e.g., pregnancy, renal failure due to ACEI, allergy, intolerance, other medical reasons). * Documentation of patient reason(s) for not prescribing ACE inhibitor or ARB or ARNI therapy (e.g., patient declined, other patient reasons).

Criteria: Denominator Exceptions

Numerator

ID: Numerator_1
Description:

Patients who were prescribed or already taking ACE inhibitor or ARB or ARNI therapy during the measurement period

Criteria: Numerator

Supplemental Data Guidance Guidance For every patient evaluated by this measure also identify payer, race, ethnicity and sex

Supplemental Data Elements

Supplemental Data Element ID: sde-ethnicity
Usage Code: Supplemental Data
Description: SDE Ethnicity
Logic Definition: SDE Ethnicity

Supplemental Data Element ID: sde-payer
Usage Code: Supplemental Data
Description: SDE Payer
Logic Definition: SDE Payer

Supplemental Data Element ID: sde-race
Usage Code: Supplemental Data
Description: SDE Race
Logic Definition: SDE Race

Supplemental Data Element ID: sde-sex
Usage Code: Supplemental Data
Description: SDE Sex
Logic Definition: SDE Sex

Measure Logic

Primary Library CMS135FHIRACEIorARBorARNIforHF

Contents Population Criteria
Logic Definitions
Terminology
Dependencies
Data Requirements
Parameters

Population Criteria

Measure Group (Rate) (ID: Group_1)

Initial Population

define "Initial Population":
  AHA."Is Adult With Two Qualifying Outpatient Encounters and One Heart Failure Outpatient Encounter During the Measurement Period"

Definition

Denominator

define "Denominator":
  "Initial Population"
    and exists AHA."Heart Failure Outpatient Encounter with History of Moderate or Severe LVSD"

Definition

Denominator Exclusion

define "Denominator Exclusions":
  AHA."Has Heart Transplant"
    or AHA."Has Heart Transplant Complications"
    or AHA."Has Left Ventricular Assist Device"
    or AHA."Has Left Ventricular Assist Device Complications"

Definition

Denominator Exception

define "Denominator Exceptions":
  "Has Medical or Patient Reason for Not Ordering ACEI or ARB or ARNI"
    or "Has Allergy or Intolerance to ACEI or ARB or ARNI Ingredient"
    or "Has Diagnosis of Allergy or Intolerance to ACEI or ARB"
    or "Has Diagnosis of Pregnancy"
    or "Has Diagnosis of Renal Failure Due to ACEI"

Definition

Numerator

define "Numerator":
  "Has ACEI or ARB or ARNI Ordered"
    or "Is Currently Taking ACEI or ARB or ARNI"

Definition

Logic Definitions

Logic Definition Library Name: SupplementalDataElements

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

Logic Definition Library Name: SupplementalDataElements

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

Logic Definition Library Name: SupplementalDataElements

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

Logic Definition Library Name: SupplementalDataElements

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

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

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

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Has ACEI or ARB or ARNI Ordered":
  exists ( [MedicationRequest: medication in "ACE Inhibitor or ARB or ARNI"] ACEIOrARBOrARNIOrdered
      where ACEIOrARBOrARNIOrdered.isOrderedDuringHeartFailureOutpatientEncounter ( )
  )

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Is Currently Taking ACEI or ARB or ARNI":
  exists ( [MedicationRequest: medication in "ACE Inhibitor or ARB or ARNI"] ActiveACEIOrARBOrARNI
      where ActiveACEIOrARBOrARNI.overlapsAfterHeartFailureOutpatientEncounter ( )
  )

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Numerator":
  "Has ACEI or ARB or ARNI Ordered"
    or "Is Currently Taking ACEI or ARB or ARNI"

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Initial Population":
  AHA."Is Adult With Two Qualifying Outpatient Encounters and One Heart Failure Outpatient Encounter During the Measurement Period"

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Denominator":
  "Initial Population"
    and exists AHA."Heart Failure Outpatient Encounter with History of Moderate or Severe LVSD"

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

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

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

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

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Denominator Exclusions":
  AHA."Has Heart Transplant"
    or AHA."Has Heart Transplant Complications"
    or AHA."Has Left Ventricular Assist Device"
    or AHA."Has Left Ventricular Assist Device Complications"

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

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

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Has Medical or Patient Reason for Not Ordering ACEI or ARB or ARNI":
  exists ( [MedicationNotRequested: medication in "ACE Inhibitor or ARB or ARNI"] NoACEIOrARBOrARNIOrdered
      where NoACEIOrARBOrARNIOrdered.isMedicationNotRequestedOrderedDuringHeartFailureOutpatientEncounter ( )
        and ( NoACEIOrARBOrARNIOrdered.reasonCode in "Medical Reason"
            or NoACEIOrARBOrARNIOrdered.reasonCode in "Patient Reason"
            or NoACEIOrARBOrARNIOrdered.reasonCode in "Patient Reason for ACE Inhibitor or ARB Decline"
        )
  )

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Has Allergy or Intolerance to ACEI or ARB or ARNI Ingredient":
  exists ( ( [AllergyIntolerance: "ACE Inhibitor or ARB or ARNI Ingredient"]
      union [AllergyIntolerance: "Substance with angiotensin-converting enzyme inhibitor mechanism of action (substance)"]
      union [AllergyIntolerance: "Substance with angiotensin II receptor antagonist mechanism of action (substance)"]
      union [AllergyIntolerance: "Substance with neprilysin inhibitor mechanism of action (substance)"] ) ACEIOrARBOrARNIAllergyIntolerance
      where ACEIOrARBOrARNIAllergyIntolerance.overlapsAfterHeartFailureOutpatientEncounter ( )
  )

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Has Diagnosis of Allergy or Intolerance to ACEI or ARB":
  exists ( (
    ["Condition": "Allergy to ACE Inhibitor or ARB"]
      union ["Condition": "Intolerance to ACE Inhibitor or ARB"]
   ) ACEIOrARBAllergyOrIntoleranceDiagnosis
      where ACEIOrARBAllergyOrIntoleranceDiagnosis.overlapsAfterHeartFailureOutpatientEncounter ( )
  )

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Has Diagnosis of Pregnancy":
  exists ( ( [Condition: "Pregnancy"] ) PregnancyDiagnosis
      with AHA."Heart Failure Outpatient Encounter with History of Moderate or Severe LVSD" ModerateOrSevereLVSDHFOutpatientEncounter
        such that PregnancyDiagnosis.prevalenceInterval ( ) starts 9 months or less before or on start of ModerateOrSevereLVSDHFOutpatientEncounter.period
          and PregnancyDiagnosis.isVerified ( )
  )
    or exists ( [USCore.ObservationPregnancyStatusProfile] PregnantObservation
        with AHA."Heart Failure Outpatient Encounter with History of Moderate or Severe LVSD" ModerateOrSevereLVSDHFOutpatientEncounter
          such that PregnantObservation.effective.toInterval ( ) starts 9 months or less before or on start of ModerateOrSevereLVSDHFOutpatientEncounter.period
            and ( PregnantObservation.value in "Pregnancy"
                and PregnantObservation.status in { 'final', 'amended', 'corrected' }
            )
    )

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Has Diagnosis of Renal Failure Due to ACEI":
  exists ( ( [Condition: "Acute renal failure caused by angiotensin-converting-enzyme inhibitor (disorder)"] ) RenalFailureDueToACEI
      where RenalFailureDueToACEI.overlapsHeartFailureOutpatientEncounter ( )
  )

Logic Definition Library Name: CMS135FHIRACEIorARBorARNIforHF

define "Denominator Exceptions":
  "Has Medical or Patient Reason for Not Ordering ACEI or ARB or ARNI"
    or "Has Allergy or Intolerance to ACEI or ARB or ARNI Ingredient"
    or "Has Diagnosis of Allergy or Intolerance to ACEI or ARB"
    or "Has Diagnosis of Pregnancy"
    or "Has Diagnosis of Renal Failure Due to ACEI"

Logic Definition Library Name: FHIRHelpers

define function ToString(value string): value.value

Logic Definition Library Name: FHIRHelpers

define function ToString(value uri): value.value

Logic Definition Library Name: FHIRHelpers

/*
@description: Converts the given FHIR [CodeableConcept](https://hl7.org/fhir/datatypes.html#CodeableConcept) value to a CQL Concept.
*/
define function ToConcept(concept FHIR.CodeableConcept):
    if concept is null then
        null
    else
        System.Concept {
            codes: concept.coding C return ToCode(C),
            display: concept.text.value
        }

Logic Definition Library Name: FHIRHelpers

/*
@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
        }

Logic Definition Library Name: FHIRHelpers

define function ToDateTime(value dateTime): value.value

Logic Definition Library Name: FHIRHelpers

/*
@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]

Logic Definition Library Name: FHIRHelpers

define function ToDateTime(value instant): value.value

Logic Definition Library Name: FHIRHelpers

define function ToDate(value date): value.value

Logic Definition Library Name: FHIRHelpers

/*
@description: Converts the given FHIR [Quantity](https://hl7.org/fhir/datatypes.html#Quantity) 
value to a CQL Quantity
@comment: If the given quantity has a comparator specified, a runtime error is raised. If the given quantity
has a system other than UCUM (i.e. `http://unitsofmeasure.org`) or CQL calendar units (i.e. `http://hl7.org/fhirpath/CodeSystem/calendar-units`)
an error is raised. For UCUM to calendar units, the `ToCalendarUnit` function is used.
@seealso: ToCalendarUnit
*/
define function ToQuantity(quantity FHIR.Quantity):
    case
        when quantity is null then null
        when quantity.value is null then null
        when quantity.comparator is not null then
            Message(null, true, 'FHIRHelpers.ToQuantity.ComparatorQuantityNotSupported', 'Error', 'FHIR Quantity value has a comparator and cannot be converted to a System.Quantity value.')
        when quantity.system is null or quantity.system.value = 'http://unitsofmeasure.org'
              or quantity.system.value = 'http://hl7.org/fhirpath/CodeSystem/calendar-units' then
            System.Quantity { value: quantity.value.value, unit: ToCalendarUnit(Coalesce(quantity.code.value, quantity.unit.value, '1')) }
        else
            Message(null, true, 'FHIRHelpers.ToQuantity.InvalidFHIRQuantity', 'Error', 'Invalid FHIR Quantity code: ' & quantity.unit.value & ' (' & quantity.system.value & '|' & quantity.code.value & ')')
    end

Logic Definition Library Name: FHIRHelpers

/*
@description: Converts a UCUM definite duration unit to a CQL calendar duration
unit using conversions specified in the [quantities](https://cql.hl7.org/02-authorsguide.html#quantities) 
topic of the CQL specification.
@comment: Note that for durations above days (or weeks), the conversion is understood to be approximate
*/
define function ToCalendarUnit(unit System.String):
    case unit
        when 'ms' then 'millisecond'
        when 's' then 'second'
        when 'min' then 'minute'
        when 'h' then 'hour'
        when 'd' then 'day'
        when 'wk' then 'week'
        when 'mo' then 'month'
        when 'a' then 'year'
        else unit
    end

Logic Definition Library Name: FHIRHelpers

define function ToString(value EncounterStatus): value.value

Logic Definition Library Name: FHIRHelpers

define function ToString(value ObservationStatus): value.value

Logic Definition Library Name: FHIRHelpers

define function ToString(value MedicationRequestStatus): value.value

Logic Definition Library Name: FHIRHelpers

define function ToString(value MedicationRequestIntent): value.value

Logic Definition Library Name: FHIRHelpers

define function ToString(value ProcedureStatus): value.value

Logic Definition Library Name: USCoreCommon

/*
@description: Returns the sex element as defined for the USCore patient profile
*/
define fluent function sex(patient Patient):
  patient.ext('http://hl7.org/fhir/us/core/StructureDefinition/us-core-sex').value as FHIR.code

Logic Definition Library Name: USCoreCommon

define fluent function ethnicity(patient Patient):
  (patient.ext('http://hl7.org/fhir/us/core/StructureDefinition/us-core-ethnicity')) E
    return {
      ombCategory: E.ext('ombCategory').value as FHIR.Coding,
      detailed: (E.exts('detailed')) d return d.value as FHIR.Coding,
      text: E.ext('text').value as FHIR.string
    }

Logic Definition Library Name: USCoreCommon

define fluent function race(patient Patient):
  (patient.ext('http://hl7.org/fhir/us/core/StructureDefinition/us-core-race')) E
    return {
      ombCategory: (E.exts('ombCategory')) o return o.value as FHIR.Coding,
      detailed: (E.exts('detailed')) d return d.value as FHIR.Coding,
      text: E.ext('text').value as FHIR.string
    }

Logic Definition Library Name: FHIRCommon

/*
@description: Returns the single extension (if present) on the given resource with the specified url.
@comment: This function uses singleton from to ensure that a run-time exception is thrown if there
is more than one extension on the given resource with the specified url.
*/
define fluent function ext(domainResource DomainResource, url String):
  singleton from domainResource.exts(url)

Logic Definition Library Name: FHIRCommon

/*
@description: Returns any extensions defined on the given resource with the specified url
*/
define fluent function exts(domainResource DomainResource, url String):
  domainResource.extension E
    where E.url = url
    return E

Logic Definition Library Name: FHIRCommon

/*
@description: Returns an interval representing the normalized prevalence period of a given Condition resource.
@comment: Uses the toInterval and toAbatementInterval functions to determine the widest potential interval from
onset to abatement as specified in the given Condition.
*/
define fluent function prevalenceInterval(condition Condition):
if condition.clinicalStatus ~ "active"
  or condition.clinicalStatus ~ "recurrence"
  or condition.clinicalStatus ~ "relapse" then
  Interval[start of condition.onset.toInterval(), end of condition.abatementInterval()]
else
  (end of condition.abatementInterval()) abatementDate
    return 
	  if abatementDate is null then
        Interval[start of condition.onset.toInterval(), abatementDate)
      else
        Interval[start of condition.onset.toInterval(), abatementDate]

Logic Definition Library Name: FHIRCommon

/*
@description: Normalizes a value that is a choice of timing-valued types to an equivalent interval
@comment: Normalizes a choice type of FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instance, FHIR.string, FHIR.Age, or FHIR.Range types
to an equivalent interval. This selection of choice types is a superset of the majority of choice types that are used as possible
representations for timing-valued elements in FHIR, allowing this function to be used across any resource.

The input can be provided as a dateTime, Period, Timing, instant, string, Age, or Range.
The intent of this function is to provide a clear and concise mechanism to treat single
elements that have multiple possible representations as intervals so that logic doesn't have to account
for the variability. More complex calculations (such as medication request period or dispense period
calculation) need specific guidance and consideration. That guidance may make use of this function, but
the focus of this function is on single element calculations where the semantics are unambiguous.
If the input is a dateTime, the result a DateTime Interval beginning and ending on that dateTime.
If the input is a Period, the result is a DateTime Interval.
If the input is a Timing, an error is raised indicating a single interval cannot be computed from a Timing.
If the input is an instant, the result is a DateTime Interval beginning and ending on that instant.
If the input is a string, an error is raised indicating a single interval cannot be computed from a string.
If the input is an Age, the result is a DateTime Interval beginning when the patient was the given Age,
and ending immediately prior to when the patient was the given Age plus one year.
If the input is a Range, the result is a DateTime Interval beginning when the patient was the Age given
by the low end of the Range, and ending immediately prior to when the patient was the Age given by the
high end of the Range plus one year.

NOTE: Due to the
complexity of determining a single interval from a Timing or String type, this function will throw a run-time exception if it is used
with a Timing or String.
*/
define fluent function toInterval(choice Choice<FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instant, FHIR.string, FHIR.Age, FHIR.Range>):
  case
    when choice is FHIR.dateTime then
      Interval[FHIRHelpers.ToDateTime(choice as FHIR.dateTime), FHIRHelpers.ToDateTime(choice as FHIR.dateTime)]
    when choice is FHIR.Period then
      FHIRHelpers.ToInterval(choice as FHIR.Period)
    when choice is FHIR.instant then
      Interval[FHIRHelpers.ToDateTime(choice as FHIR.instant), FHIRHelpers.ToDateTime(choice as FHIR.instant)]
    when choice is FHIR.Age then
      Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age),
        FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age) + 1 year)
    when choice is FHIR.Range then
      Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).low),
        FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).high) + 1 year)
    when choice is FHIR.Timing then
      Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a Timing value is not supported')
    when choice is FHIR.string then
      Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a String value is not supported')
    else
      null as Interval<DateTime>
  end

Logic Definition Library Name: FHIRCommon

/*
@description: Returns an interval representing the normalized Abatement of a given Condition resource.
@comment: @comment: If the abatement element of the Condition is represented as a DateTime, the result
is an interval beginning and ending on that DateTime.
If the abatement is represented as a Quantity, the quantity is expected to be a calendar-duration and is interpreted as the age of the patient. The
result is an interval from the date the patient turned that age to immediately before one year later.
If the abatement is represented as a Quantity Interval, the quantities are expected to be calendar-durations and are interpreted as an age range during
which the abatement occurred. The result is an interval from the date the patient turned the starting age of the quantity interval, and ending immediately
before one year later than the date the patient turned the ending age of the quantity interval.

NOTE: Due to the complexity of determining an interval from a String, this function will throw
a run-time exception if used with a Condition instance that has a String as the abatement value.
*/
define fluent function abatementInterval(condition Condition):
  if condition.abatement is FHIR.dateTime then
    Interval[FHIRHelpers.ToDateTime(condition.abatement as FHIR.dateTime), FHIRHelpers.ToDateTime(condition.abatement as FHIR.dateTime)]
  else if condition.abatement is FHIR.Period then
    FHIRHelpers.ToInterval(condition.abatement as FHIR.Period)
  else if condition.abatement is FHIR.string then
    Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a String value is not supported')
  else if condition.abatement is FHIR.Age then
    Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(condition.abatement as FHIR.Age),
      FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(condition.abatement as FHIR.Age) + 1 year)
  else if condition.abatement is FHIR.Range then
    Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((condition.abatement as FHIR.Range).low),
      FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((condition.abatement as FHIR.Range).high) + 1 year)
  else if condition.abatement is FHIR.boolean then
    Interval[end of condition.onset.toInterval(), condition.recordedDate)
  else 
    null

Logic Definition Library Name: FHIRCommon

/*
@description: Returns true if the given condition either has no verification status or has a verification status of confirmed, unconfirmed, provisional, or differential
*/
define fluent function isVerified(condition FHIR.Condition):
  condition.verificationStatus is not null implies
    (condition.verificationStatus ~ "confirmed"
      or condition.verificationStatus ~ "unconfirmed"
      or condition.verificationStatus ~ "provisional"
      or condition.verificationStatus ~ "differential"
    )

Logic Definition Library Name: FHIRCommon

/*
@description: Returns true if the given reference is to the given resource
@comment: Returns true if the `id` element of the given resource exactly equals the tail of the given reference.
NOTE: This function assumes resources from the same source server.
*/
define fluent function references(reference FHIR.Reference, resource FHIR.Resource):
  resource.id = Last(Split(reference.reference, '/'))

Logic Definition Library Name: FHIRCommon

/*
@description: Returns the single extension (if present) on the given element with the specified url.
@comment: This function uses singleton from to ensure that a run-time exception is thrown if there
is more than one extension on the given element with the specified url.
*/
define fluent function ext(element Element, url String):
  singleton from element.exts(url)

Logic Definition Library Name: FHIRCommon

/*
@description: Returns any extensions defined on the given element with the specified url.
*/
define fluent function exts(element Element, url String):
  element.extension E
    where E.url = url
    return E

Logic Definition Library Name: FHIRCommon

/*
@description: Returns true if the given condition either has no verification status or has a verification status of confirmed, unconfirmed, provisional, or differential
*/
define fluent function isVerified(allergyIntolerance FHIR.AllergyIntolerance):
  allergyIntolerance.verificationStatus is not null implies
    (allergyIntolerance.verificationStatus ~ "allergy-confirmed"
      or allergyIntolerance.verificationStatus ~ "allergy-unconfirmed"
    )