library OMTKLogicMK2020 version '2022.1.0'
/*
This version of the OMTKLogic library uses the FHIR MedicationKnowledge Resource
as the source for drug ingredient and strength information, rather than the
OMTK data source.
*/
using FHIR version '4.0.1'
include OMTKData2020 version '2022.1.0' called OMTKData
codesystem RxNorm: 'http://www.nlm.nih.gov/research/umls/rxnorm'
context Patient
/*
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 System.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 'Error: unknown{' + unit + '}'
end
/*
Calculates daily frequency given frequency within a period
*/
define function ToDaily(frequency System.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 System.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) 2.4
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 System.Code, dailyDose System.Quantity, doseFormCode System.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) = 858080 then 0.18 /* Buccal Film */
when ToInteger(doseFormCode.code) in { 126542, 346163 } then 0.16 /* Nasal Spray, Mucosal Spray */
when IsPatch(doseFormCode) then 2.4 /* 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 System.Quantity):
if strength.value < 0.1 and (PositionOf('mg', strength.unit) = 0) then
System.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
}>
*/
/*
DrugIngredients:
List<{
drugCode Integer,
drugName String,
doseFormCode Integer,
doseFormName String,
ingredientCode Integer,
ingredientName String,
strength String,
strengthValue Decimal,
strengthUnit String
}>
*/
define function GetIngredients(rxNormCode System.Code):
OMTKData.DrugIngredients DI
where DI.drugCode = ToInteger(rxNormCode.code)
return {
rxNormCode: System.Code { code: ToString(DI.drugCode), system: 'http://www.nlm.nih.gov/research/umls/rxnorm', display: DI.drugName },
doseFormCode: System.Code { code: ToString(DI.doseFormCode), system: 'http://www.nlm.nih.gov/research/umls/rxnorm', display: DI.doseFormName },
doseFormName: DI.doseFormName,
ingredientCode: System.Code { code: ToString(DI.ingredientCode), system: 'http://www.nlm.nih.gov/research/umls/rxnorm', display: DI.ingredientName },
ingredientName: DI.ingredientName,
strength: EnsureMicrogramQuantity(
System.Quantity {
value: DI.strengthValue,
unit: ToUCUM(DI.strengthUnit)
}
)
}
/* define function GetIngredients(rxNormCode Code):
flatten (
[MedicationKnowledge: rxNormCode] M
return
M.ingredient I
where I.code in "Opioid Ingredients" // TODO: Need a value set of opioid ingredients
return {
rxNormCode: M.code,
doseFormCode: M.doseForm, // TODO: MedicationKnowledge specifies SNOMED-CT dose forms here, would need to profile to RXNorm
doseFormName: M.doseForm.text,
ingredientCode: I.item as CodeableConcept, // TODO: Profile to code only
ingredientName: (I.item as CodeableConcept).text,
strength: EnsureMicrogramQuantity(I.strength.denominator) // TODO: Is this correct?
}
) */
/*
Calculates daily dose for a specific ingredient based on the ingredient strength, dose form, dose quantity, and daily frequency
*/
define function GetDailyDose(ingredientCode System.Code, strength System.Quantity, doseFormCode System.Code, doseQuantity System.Quantity, dosesPerDay System.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
System.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
System.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
System.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
System.Quantity {
value: dosesPerDay * doseQuantity.value * strength.value,
unit: Substring(strength.unit, 0, PositionOf('/', strength.unit))
}
end
define function GetMedicationName(rxNormCode System.Code):
if rxNormCode.display is null then
SingletonFrom(
OMTKData.DrugIngredients DI
where DI.drugCode = ToInteger(rxNormCode.code)
return DI.drugName
)
else rxNormCode.display
/*
Builds a description for the daily dose for an ingredient
*/
define function GetDailyDoseDescription(ingredientCode System.Code, ingredientName System.String, strength System.Quantity, doseFormCode System.Code, doseFormName System.String, doseQuantity System.Quantity, dosesPerDay System.Decimal, dailyDose System.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.value) + ' = ' + ToString(dailyDose.value)
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.value) + ' = ' + ToString(dailyDose.value)
/* 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.value) + ' * ' + ToString(strength.value) + ' = ' + ToString(dailyDose.value)
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 System.Code, doseQuantity System.Quantity, dosesPerDay System.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: System.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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