/*
  Heart failure admission clinical protocol — encounter-start applicability.

  "HF Admission Applicable" = active heart failure condition on the chart
  (encounter diagnosis or problem list, atrius-vs-heart-failure ValueSet from
  the CMS165 terminology stack).

  "No Recent BNP" gates the admission natriuretic peptide draw: skip when a
  BNP or NT-proBNP resulted within the last 24 hours.

  PlanDefinition type is clinical-protocol (eligibility + conditional BNP +
  nested admission bundle). Library version stays 0.1.0; PlanDefinition is 0.2.0.
*/
library AtriusHFAdmission version '0.1.0'

using FHIR version '4.0.1'
using AtriusIn version '0.1.0'

include FHIRHelpers version '4.4.000' called FHIRHelpers
include AtriusCommon version '0.1.0'

codesystem "LOINC": 'http://loinc.org'

valueset "Heart Failure": 'https://atrius.in/fhir/r4/atrius-in/ValueSet/atrius-vs-heart-failure'

code "BNP": '30934-4' from "LOINC" display 'Natriuretic peptide B [Mass/volume] in Serum or Plasma'
code "NT-proBNP": '33762-6' from "LOINC" display 'Natriuretic peptide.B prohormone N-Terminal [Mass/volume] in Serum or Plasma'

context Patient

define "Heart Failure Conditions":
  ([ConditionEncounterDiagnosis: "Heart Failure"] union [ConditionProblemsHealthConcerns: "Heart Failure"]) C
    where C.isActive()

define "HF Admission Applicable":
  exists "Heart Failure Conditions"

define "Recent BNP Observations":
  [Observation] O
    where O.status in { 'final', 'amended', 'corrected' }
      and (O.code ~ "BNP" or O.code ~ "NT-proBNP")
      and O.effective.toObservationEffectiveInterval() starts after (Now() - 24 hours)

define "No Recent BNP":
  "HF Admission Applicable"
    and not exists "Recent BNP Observations"

Encoded data