Release 4B Ballot #1

This page is part of the FHIR Specification (v4.1.0: Release 4B Ballot #1). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4

Library-omtk-logic

Clinical Decision Support Work GroupMaturity Level: N/AStandards Status: InformativeCompartments: Not linked to any defined compartments

This is the narrative for the resource. See also the XML, JSON or Turtle format. This example conforms to the profile Library.


Participants

AuthorKensaku Kawamoto, MD, PhD, MHS
AuthorBryn Rhodes
AuthorFloyd Eisenberg, MD, MPH
AuthorRobert McClure, MD, MPH

Related Artifacts

Depends Onhttp://example.org/fhir/Library/omtk-modelinfo
DocumentationCDC guideline for prescribing opioids for chronic painhttps://guidelines.gov/summaries/summary/50153/cdc-guideline-for-prescribing-opioids-for-chronic-pain---united-states-2016#420
DocumentationMME Conversion Tableshttps://www.cdc.gov/drugoverdose/pdf/calculating_total_daily_dose-a.pdf

Contents

text/cql

library OMTKLogic version '0.1.0'

using OMTK version '0.1.0'

codesystem RxNorm: 'http://www.nlm.nih.gov/research/umls/rxnorm'

//define MED_DOSE_FORMS: [MED_DOSE_FORM]

// Given an RxNorm Code:
// NON_SURGICAL_OPIOID_TO_INCLUDE.DRUG_RXCUI
// MED_DRUG.DRUG_RXCUI
// MED_SCDC_FOR_DRUG.DRUG_RXCUI -> SCDC_RXCUI
// MED_SCDC.SCDC_RXCUI (STRENGTH, STRENGTH_VALUE, STRENGTH_UNIT)
// MED_INGREDIENT_FOR_SCDC.SCDC_RXCUI -> INGREDIENT_RXCUI
// MED_INGREDIENT.INGREDIENT_RXCUI
// MED_INGREDIENT_TYPE.INGREDIENT_RXCUI (INGREDIENT_TYPE = 'NonSurgicalOpioid')

/*
 SQL ->
select D.DRUG_RXCUI, D.DRUG_NAME, DF.DOSE_FORM_NAME, SCDCD.SCDC_RXCUI, SCDC.SCDC_NAME, SCDC.STRENGTH, SCDC.STRENGTH_VALUE, SCDC.STRENGTH_UNIT, I.INGREDIENT_RXCUI, I.INGREDIENT_NAME
  from MED_DRUG D
    join NON_SURGICAL_OPIOID_TO_INCLUDE NSO on D.DRUG_RXCUI = NSO.DRUG_RXCUI
    join MED_SCDC_FOR_DRUG SCDCD on D.DRUG_RXCUI = SCDCD.DRUG_RXCUI
    join MED_SCDC SCDC on SCDCD.SCDC_RXCUI = SCDC.SCDC_RXCUI
    join MED_INGREDIENT_FOR_SCDC SCDCI on SCDC.SCDC_RXCUI = SCDCI.SCDC_RXCUI
    join MED_INGREDIENT I on SCDCI.INGREDIENT_RXCUI = I.INGREDIENT_RXCUI
    join MED_INGREDIENT_TYPE IT on I.INGREDIENT_RXCUI = IT.INGREDIENT_RXCUI
	left join MED_DRUG_DOSE_FORM DDF on D.DRUG_RXCUI = DDF.DRUG_RXCUI
	left join MED_DOSE_FORM DF on DDF.DOSE_FORM_RXCUI = DF.DOSE_FORM_RXCUI
	--Most of the drugs have multiple dose form groups...
	--left join MED_DRUG_DOSE_FORM_GROUP DDFG on D.DRUG_RXCUI = DDFG.DRUG_RXCUI
	--left join MED_DOSE_FORM_GROUP DFG on DDFG.DOSE_FORM_GROUP_RXCUI = DFG.DOSE_FORM_GROUP_RXCUI
  where D.DRUG_RXCUI = @RxNormCode // 197696
    and IT.INGREDIENT_TYPE = 'NonSurgicalOpioid'
*/

/*
  CQL, assuming translation to SQL:

  from
    [MED_DRUG: rxNormCode] D,
    [NON_SURGICAL_OPIOID_TO_INCLUDE] NSO,
    [MED_SCDC_FOR_DRUG] SCDCD,
    [MED_SCDC] SCDC,
    [MED_INGREDIENT_FOR_SCDC] SCDCI,
    [MED_INGREDIENT] I,
    [MED_INGREDIENT_TYPE] IT,
    [MED_DRUG_DOSE_FORM] DDF,
    [MED_DOSE_FORM] DF
  where D.DRUG_RXCUI = NSO.DRUG_RXCUI
    and D.DRUG_RXCUI = SCDCD.DRUG_RXCUI
    and SCDCD.SCDC_RXCUI = SCDC.SCDC_RXCUI
    and SCDC.SCDC_RXCUI = SCDCI.SCDC_RXCUI
    and SDCDI.INGREDIENT_RXCUI = I.INGREDIENT_RXCUI
    and I.INGREDIENT_RXCUI = IT.INGREDIENT_RXCUI
    and D.DRUG_RXCUI = DDF.DRUG_RXCUI
    and DDF.DOSE_FORM_RXCUI = DF.DOSE_FORM_RXCUI
    and IT.INGREDIENT_TYPE = 'NonSurgicalOpioid'
*/

/*
An engine with a naive implementation for multi-source queries would perform
pretty horribly here, so rewrite it using "syntactic optimization" :)
*/

/*
  Normalizes the input units to UCUM units
  
  Note guidance for UCUM presentation of medication units from SNOMED here:
  https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjU3vLpicPTAhWFMGMKHRpOBUAQFggiMAA&url=https%3A%2F%2Fconfluence.ihtsdotools.org%2Fdownload%2Fattachments%2F17859188%2FExpressing%2520Units%2520of%2520Measure%2520for%2520Medicinal%2520Products.doc%3Fapi%3Dv2&usg=AFQjCNE5sboicqvJDUyXJ2im8VzBpgHE8A
  
  The values listed here are the only ones currently present in the OMTK data
  
  Based on the HL7 UCUM subset here:
  http://download.hl7.de/documents/ucum/ucumdata.html
*/
define function ToUCUM(unit String):
  case unit
    when 'MG' then 'mg'
    when 'MG/ACTUAT' then 'mg/{actuat}'
    when 'MG/HR' then 'mg/h'
    when 'MG/ML' then 'mg/mL'
    else 'unknown{' + unit + '}' // Should probably be an error
  end

/*
  Calculates daily frequency given frequency within a period
*/
define function ToDaily(frequency Integer, period System.Quantity):
  case period.unit
    when 'h' then frequency * (24.0 / period.value)
    when 'min' then frequency * (24.0 / period.value) * 60
    when 's' then frequency * (24.0 / period.value) * 60 * 60
    when 'd' then frequency * (24.0 / period.value) / 24
    when 'wk' then frequency * (24.0 / period.value) / (24 * 7)
    when 'mo' then frequency * (24.0 / period.value) / (24 * 30) // assuming 30 days in month
    when 'a' then frequency * (24.0 / period.value) / (24 * 365) // assuming 365 days in year
    else null
  end

/*
  Returns true if the given dose form is a patch (transdermal system)
*/
define function IsPatch(doseFormCode Code):
  ToInteger(doseFormCode.code) = 316987

/*
  Returns the conversion factor for the given ingredient

Opioid (strength in mg except where noted)	MME Conversion Factor*
Buprenorphine, transdermal patch (MCG/HR)	12.6
Buprenorphine, tablet or film	30
Buprenorphine, film (MCG)	0.03
Butorphanol	7
Codeine	0.15
Dihydrocodeine	0.25
Fentanyl, buccal/SL tabet or lozenge/troche (MCG)	0.13
Fentanyl, film or oral spray (MCG)	0.18
Fentanyl, nasal spray (MCG)	0.16
Fentanyl, transdermal patch (MCG/HR)	7.2
Hydrocodone	1
Hydromorphone	4
Levomethadyl acetate	8
Levorphanol tartrate	11
Meperidine 	0.1
Methadone	3
  1-20 mg/d 4
  21-40 mg/d 8
  41-60 mg/d 10
  61-80 mg/d 12
Morphine	1
Opium	1 // NOTE: Not present as an ingredient in the RxNorm data
Oxycodone	1.5
Oxymorphone	3
Pentazocine	0.37
Tapentadol	0.4
Tramadol	0.1

*/
define function GetConversionFactor(ingredientCode Code, dailyDose Quantity, doseFormCode Code):
  case ToInteger(ingredientCode.code)
    when 161 then 0 //	Acetaminophen
    when 1191 then 0 //	Aspirin
    when 1223 then 0 //	Atropine
    when 1767 then 0 //	Brompheniramine
    when 1819 then ( //	Buprenorphine
      case 
        when ToInteger(doseFormCode.code) = 316987 then 12.6 // Transdermal system
        else 30 // Tablet or Film (or Film in MCG)
      end
    ) 
    when 1841 then 7 //	Butorphanol
    when 1886 then 0 //	Caffeine
    when 2101 then 0 //	Carisoprodol
    when 2354 then 0 //	chlorcyclizine
    when 2400 then 0 //	Chlorpheniramine
    when 2670 then 0.15 //	Codeine
    when 3423 then 4 //	Hydromorphone
    when 3498 then 0 //	Diphenhydramine
    when 4337 then ( //	Fentanyl
      case
        when ToInteger(doseFormCode.code) in { 970789, 317007, 316992 } then 0.13 // Buccal Tablet, Sublingual Tablet, Oral Lozenge
        when ToInteger(doseFormCode.code) = 346163 then 0.18 // Buccal Film
        when ToInteger(doseFormCode.code) in { 126542, 346163 } then 0.16 // Nasal Spray, Mucosal Spray
        when IsPatch(doseFormCode) then 7.2 // Transdermal system
        else 1000 // Really ought to be an error because it represents a previously unencountered dose form....
      end
    )
    when 5032 then 0 //	Guaifenesin
    when 5489 then 1 //	Hydrocodone
    when 5640 then 0 //	Ibuprofen
    when 6102 then 0 //	Kaolin
    when 6378 then 11 //	Levorphanol (NOTE: Given as Levorphanol tartrate in the CDC conversion table)
    when 6754 then 0.1 //	Meperidine
    when 6813 then ( //	Methadone
      case
        when dailyDose.value between 1 and 20 then 4
        when dailyDose.value between 21 and 40 then 8
        when dailyDose.value between 41 and 60 then 10
        when dailyDose.value >= 61 then 12
        else 1000 // Really ought to be an error because it represents an unexpected dose range...
      end
    )
    when 7052 then 1 //	Morphine
    when 7242 then 0 //	Naloxone
    when 7243 then 0 //	Naltrexone
    when 7804 then 1.5 //	Oxycodone
    when 7814 then 3 //	Oxymorphone
    when 8001 then 0.37 //	Pentazocine
    when 8163 then 0 //	Phenylephrine
    when 8175 then 0 //	Phenylpropanolamine
    when 8745 then 0 //	Promethazine
    when 8896 then 0 //	Pseudoephedrine
    when 9009 then 0 //	Pyrilamine
    when 10689 then 0.1 //	Tramadol
    when 10849 then 0 //	Triprolidine
    when 19759 then 0 //	bromodiphenhydramine
    when 19860 then 0 //	butalbital
    when 22696 then 0 //	dexbrompheniramine
    when 22697 then 0 //	dexchlorpheniramine
    when 23088 then 0.25 //	dihydrocodeine
    when 27084 then 0 //	homatropine
    when 35780 then 0 //	ropivacaine
    when 237005 then 8 //	Levomethadyl (NOTE: given as Levomethadyl acetate in the CDC conversion table)
    when 636827 then 0 //	guaiacolsulfonate
    when 787390 then 0.4 //	tapentadol
    else 0
  end

define function EnsureMicrogramQuantity(strength Quantity):
  if strength.value < 0.1 and (PositionOf('mg', strength.unit) = 0) then
    Quantity {
      value: strength.value * 1000,
      unit: 'mcg' + Substring(strength.unit, 2)
    }
  else
    strength

/*
  Returns the non-surgical opioid ingredients and their strengths that
  make up the drug identified by the given rxNormCode as a list of tuples:

  List<Tuple {
    rxNormCode Code,
    doseFormCode Code,
    doseFormName String,
    ingredientCode Code,
    ingredientName String,
    strength Quantity
  }>
*/
define function GetIngredients(rxNormCode Code):
  (
    [MED_SCDC_FOR_DRUG: DRUG_RXCUI in rxNormCode] SD
      where exists ([MED_DRUG_VALUE_SET: DRUG_RXCUI in SD.DRUG_RXCUI])
      return {
        rxNormCode: rxNormCode,
        component: SingletonFrom([MED_SCDC: SCDC_RXCUI in SD.SCDC_RXCUI]),
        ingredientCode: SingletonFrom([MED_SCDC: SCDC_RXCUI in SD.SCDC_RXCUI]).INGREDIENT_RXCUI,
        doseFormCode: SingletonFrom([MED_DRUG: DRUG_RXCUI in SD.DRUG_RXCUI]).DOSE_FORM_RXCUI // Could potentially look this up only once...
      }
  ) C
    let
      ingredient: SingletonFrom([MED_INGREDIENT: INGREDIENT_RXCUI in C.ingredientCode]),
      doseForm: SingletonFrom([MED_DOSE_FORM: DOSE_FORM_RXCUI in C.doseFormCode])
    where exists (
      [MED_INGREDIENT_TYPE: INGREDIENT_RXCUI in C.ingredientCode] IT
        where IT.INGREDIENT_TYPE = 'Opioid_NonSurgical'
    )
    return {
      rxNormCode: rxNormCode,
      doseFormCode: C.doseFormCode,
      doseFormName: doseForm.DOSE_FORM_NAME,
      ingredientCode: C.ingredientCode,
      ingredientName: ingredient.INGREDIENT_NAME,
      strength:
        EnsureMicrogramQuantity(
          Quantity {
            value: C.component.STRENGTH_VALUE,
            unit: ToUCUM(C.component.STRENGTH_UNIT)
          }
        )
    }

/*
  Calculates daily dose for a specific ingredient based on the ingredient strength, dose form, dose quantity, and daily frequency
*/
define function GetDailyDose(ingredientCode Code, strength Quantity, doseFormCode Code, doseQuantity Quantity, dosesPerDay Decimal):
  case
	  // if patch --> daily dose = dose value (e.g, number patches with doseQuantity unit = "patch") * per-hour strength
    when IsPatch(doseFormCode) then
      // buprenorphine or fentanyl patch
      if ToInteger(ingredientCode.code) in { 1819, 4337 } then
        Quantity { value: dosesPerDay * doseQuantity.value * strength.value, unit: strength.unit }
      else
        null

    // if dose unit in actual mass units (mg or mcg -- when it's a single med) --> daily dose = numTimesPerDay * dose
    when doseQuantity.unit in { 'mg', 'mcg' } then
      Quantity { value: dosesPerDay * doseQuantity.value, unit: doseQuantity.unit }

    // if doseQuantity is in actual volume units (mL) --> daily dose = numTimesPerDay * dose * strength
    when doseQuantity.unit = 'mL' and (PositionOf('/mL', strength.unit) = Length(strength.unit) - 3) then
      Quantity { value: dosesPerDay * doseQuantity.value * strength.value, unit: Substring(strength.unit, 0, PositionOf('/', strength.unit)) }

		// if doseQuantity is not in actual units (e.g., 1 tab, 1 spray -- when it's a combo med with a unit of tablet, or it's mg/actuat) --> daily dose = numTimesPerDay * dose value * strength value
    else
      Quantity { value: dosesPerDay * doseQuantity.value * strength.value, unit: Substring(strength.unit, 0, PositionOf('/', strength.unit)) }
  end
  
define function GetMedicationName(rxNormCode Code):
  SingletonFrom([MED_DRUG: DRUG_RXCUI in rxNormCode]).DRUG_NAME

/*
  Builds a description for the daily dose for an ingredient
*/
define function GetDailyDoseDescription(ingredientCode Code, ingredientName String, strength Quantity, doseFormCode Code, doseFormName String, doseQuantity Quantity, dosesPerDay Decimal, dailyDose Quantity):
  case
    // if patch
    when IsPatch(doseFormCode) then
      // buprenorphine or fentanyl patch
      if ToInteger(ingredientCode.code) in { 1819, 4337 } then
        ingredientName + ' patch: ' + ToString(doseQuantity.value) + ' * ' + ToString(strength) + ' = ' + ToString(dailyDose)
      else
        null

    // if dose unit in actual mass units (mg or mcg -- when it's a single med)
    when doseQuantity.unit in { 'mg', 'mcg' } then
      ingredientName + ' ' + doseFormName + ': ' + ToString(dosesPerDay) + '/d * ' + ToString(doseQuantity) + ' = ' + ToString(dailyDose)

    // if doseQuantity in actual volume units (mL) or not in actual units (e.g. 1 tab, 1 spray)
    else
      ingredientName + ' ' + doseFormName + ': ' + ToString(dosesPerDay) + '/d * ' + ToString(doseQuantity) + ' * ' + ToString(strength) + ' = ' + ToString(dailyDose)
  end

/*
  Calculates MMEs for the given input prescription information and returns it
  as a list of tuples:

  List<Tuple {
    rxNormCode Code,
    doseFormCode Code,
    doseQuantity Quantity,
    dosesPerDay Decimal,
    ingredientCode Code,
    ingredientName String,
    strength Quantity,
    dailyDose Quantity,
    dailyDoseDescription String,
    conversionFactor Decimal,
    mme Quantity
  }>
*/
define function CalculateMMEs(medications List<Tuple { rxNormCode Code, doseQuantity Quantity, dosesPerDay Decimal }>):
  Flatten(
    medications M
      let Ingredients: GetIngredients(M.rxNormCode)
      return
        Ingredients I
          let
            adjustedDoseQuantity: EnsureMicrogramQuantity(M.doseQuantity),
            dailyDose: GetDailyDose(I.ingredientCode, I.strength, I.doseFormCode, adjustedDoseQuantity, M.dosesPerDay),
            factor: GetConversionFactor(I.ingredientCode, dailyDose, I.doseFormCode)
          return {
            rxNormCode: M.rxNormCode,
            doseFormCode: I.doseFormCode,
            doseQuantity: adjustedDoseQuantity,
            dosesPerDay: M.dosesPerDay,
            ingredientCode: I.ingredientCode,
            ingredientName: I.ingredientName,
            strength: I.strength,
            dailyDose: dailyDose,
            dailyDoseDescription: GetDailyDoseDescription(I.ingredientCode, I.ingredientName, I.strength, I.doseFormCode, I.doseFormName, adjustedDoseQuantity, M.dosesPerDay, dailyDose),
            conversionFactor: factor,
            mme: Quantity {
              value: dailyDose.value * factor,
              unit: dailyDose.unit + '/d'
            }
          }
  )

define TestCalculateMMEs:
  CalculateMMEs({ { rxNormCode: Code '388508' from RxNorm, doseQuantity: Quantity { value: 1, unit: 'patch' }, dosesPerDay: 0.33 } })

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Usage note: every effort has been made to ensure that the examples are correct and useful, but they are not a normative part of the specification.