Quality Measure Implementation Guide
1.0.0 - STU 1

Quality Measure Implementation Guide - Downloaded Version null See the Directory of published versions

## Library: EXMRatio - Example Ratio Measure Library (Experimental)

Official URL: http://hl7.org/fhir/uv/cqm/Library/EXMRatio | Version: 4.0.0
Standards status: Informative | Computable Name: EXMRatio
Other Identifiers: http://example.org/fhir/cqi/ecqm/Library/Identifier#EXMRatio (use: official, ), OID:2.16.840.1.113883.4.642.40.61.28.22

This library is used as an example in the FHIR Quality Measure Implementation Guide

Metadata
Title | EXMRatio - Example Ratio Measure Library
Version | 4.0.0
Identifier | EXMRatio
Identifier | urn:oid:2.16.840.1.113883.4.642.40.61.28.22
Approval Date | 2019-08-03
Last Review Date | 2019-08-03
Experimental | true
Jurisdiction | Global (Whole world)
Steward (Publisher) | HL7 International / Clinical Quality Information
Description | This library is used as an example in the FHIR Quality Measure Implementation Guide
Type | Logic Library
Parameter | Name: Patient Use: Out Min Cardinality: 0 Max Cardinality: 1 Type: Patient
Parameter | Name: Qualifying Encounters Use: Out Min Cardinality: 0 Max Cardinality: * Type: Encounter
Parameter | Name: Initial Population Use: Out Min Cardinality: 0 Max Cardinality: * Type: Encounter
Parameter | Name: Denominator Use: Out Min Cardinality: 0 Max Cardinality: * Type: Encounter
Parameter | Name: Numerator Use: Out Min Cardinality: 0 Max Cardinality: * Type: Encounter
Parameter | Name: Falls with Major Injury Use: Out Min Cardinality: 0 Max Cardinality: * Type: Observation
Data Requirement | Type: Patient Profile(s): Patient
Data Requirement | Type: Encounter Profile(s): Encounter Must Support Elements: type Code Filter(s): Path: type ValueSet: `http://example.org/fhir/ValueSet/inpatient`
Data Requirement | Type: Observation Profile(s): Observation Must Support Elements: code, effective Code Filter(s): Path: code ValueSet: `http://example.org/fhir/ValueSet/fall`
Library Content
CQL Content |
    /*
    Measures the number of inpatient falls with major injury per 1000 patient days.

    “Patient days” are to be calculated such that:
      Sum actual hours for all patients, whether in-patient, ED or observation, and divide by 24.

    The approach we envision is starting from an encounter-based eCQM with numerator
    and denominator observations to arrive at the following:

    Patient A has a 10 day inpatient encounter. On day 1 she fell 9 times. No more falls in that stay.

    Patient B has a 2 day inpatient encounter. On day 2 he fell 1 time. No other falls in that stay

    Result: 10 falls/12 days = 833/1000 patient days

    Answer: There are multiple considerations involved in the representation of falls with major injury,
    this example does not address those considerations, focusing only on the overall structure
    of the measure and the final calculation.

    This measure can be represented as an encounter-based ratio measure, with:

    Numerator Observation: Count(Falls with Major Injury)
    Denominator Observation: Sum(Encounter Days)

    This does result in a ratio, but there isn't mechanism in the current FHIR measure
    to specify that the ratio should be converted to "per 1000 days".

    To support that aspect, we are proposing a scoringUnit extension of the Quality Measure IG
    to state the expected units of a ratio measure.

    This is submitted as a tracker to the quality measure IG here:
    https://jira.hl7.org/browse/FHIR-30506

    The included EXMRatioFHIRv603-Artifacts.zip is an export of this measure expressed
    in the MAT which includes everything but the proprosed scoringUnit extension. That
    extension is proposed for inclusion in the May 2021 ballot of the quality measure ig
    and is not supported by the MAT at this time.
    */
    library EXMRatio

    using FHIR version '4.0.1'

    include hl7.fhir.uv.cql.FHIRHelpers version '4.0.1' called FHIRHelpers

    include MATGlobalCommonFunctions version '5.0.000' called Global

    valueset "Inpatient": 'http://example.org/fhir/ValueSet/inpatient'
    valueset "Fall": 'http://example.org/fhir/ValueSet/fall'

    context Patient

    define "Initial Population":
      "Qualifying Encounters"

    define "Denominator":
      "Initial Population"

    define "Numerator":
      "Initial Population"

    define "Qualifying Encounters":
      ["Encounter": "Inpatient"]

    define "Falls with Major Injury":
      ["Observation": "Fall"]

    define function "Denominator Observation"(Encounter "Encounter"):
      duration in hours of Global.Hospitalization(Encounter) / 24

    define function "Numerator Observation"(Encounter "Encounter"):
      Count(
        "Falls with Major Injury" Falls
          where Global."Normalize Interval"(Falls.effective) during Encounter.period
      )
ELM XML Content |
    Encoded data (21956 characters)
ELM JSON Content |
    Encoded data (36248 characters)
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