Documentation
Common Data Model (CDM)
Convert Database to CDM (ETL)
Tool Specific Documentation
Common Data Model (CDM)
Convert Database to CDM (ETL)
Tool Specific Documentation
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Proposal for conventions to achieve consistent entries in the attribute quantity of the DRUG_EXPOSURE table and entries in the DRUG_STRENGTH table. Eventually, we will be able to calculate the total amount of the active ingredient by
DRUG_EXPOSURE.quantity x DRUG_STRENGTH.numerator_value [numerator_unit_concept_id]
(for concentrations) or DRUG_EXPOSURE.quantity x DRUG_STRENGTH.amount_value [amount_unit_concept_id]
(for pieces, e.g. tablets)For drugs with a dose release over time (e.g. Patches) we will be able to calculate the hourly rate by
DRUG_STRENGTH.numerator_value [numerator_unit_concept_id]
Probably, nothing has to be changed. But we should cross-check the following assumed properties of the DRUG_STRENGTH table coming from RxNorm and apply these for future enhancements:
With the above mentioned conventions the fields effective_drug_dose and dose_unit_concept_id can be removed. They don’t support multiple ingredients anyway.
In order to support quantified drugs we need an additional field denominator_value. For compounding we would need to add records to DRUG_STRENGTH for all compounds (drug_concept_id=ingredient_concept_id) with the mg concept in the denominator_unit_concept_id for all "dry" compounds and mL for the "wet" ones. We could steal the knowledge what is what from RxNorm.
1 | Tablets |
---|---|
DRUG_STRENGTH | The denominator_unit is empty |
DRUG_EXPOSURE | Quantity refers to number of pieces, e.g. tablets |
Ingredient dose= | quantity x amount_value [amount_unit_concept_id] |
2 | Puffs of an inhaler |
DRUG_STRENGTH | The denominator_unit is {actuat} |
DRUG_EXPOSURE | Quantity refers to the number of pieces, e.g. puffs |
Ingredient dose= | quantity x numerator_value [numerator_unit_concept_id] |
3 | Quantified Drugs |
Example: The Clinical Drug is Paracetamol 250 mg/mL in a 5mL oral suspension. The Quantified Clinical Drug would have 1250 mg / 5 ml in the DRUG_STRENGTH table. Two suspensions are dispensed. | |
DRUG_STRENGTH | The denominator_unit is either mg or mL. The denominator_value might be different from 1. |
DRUG_EXPOSURE | Quantity refers to a fraction or multiple of the pack. |
Example: 2 | |
Ingredient dose= | quantity x numerator_value [numerator_unit_concept_id] |
Paracetamol dose = 2 x 1250mg = 2500mg |
|
4 | Drugs with the total amount in quantity |
Example: 42799258 “Benzyl Alcohol 0.1 ML/ML / Pramoxine hydrochloride 0.01 MG/MG Topical Gel” dispensed in a 1.25oz pack. | |
DRUG_STRENGTH | The denominator_unit is either mg or mL. |
Example: Benzyl Alcohol in mL and Pramoxine hydrochloride in mg | |
DRUG_EXPOSURE | Quantity refers to mL or g. |
Example: 1.25 x 30 (conversion factor oz → mL) = 37 | |
Ingredient dose= | quantity x numerator_value [numerator_unit_concept_id] |
Benzyl Alcohol dose = 37 x 0.1mL = 3.7mL |
|
Pramoxine hydrochloride dose = 37 x 0.01mg x 1000 = 370mg |
|
Note: The analytical side checks the denominator in the DRUG_STRENGTH table. As mg is used for the second ingredient the factor 1000 will be applied to convert between g and mg. | |
5 | Compounding |
Example: Ibuprofen 20%/Piroxicam 1% Cream, 30ml in 5ml tubes. | |
DRUG_STRENGTH | We need entries for the ingredients of Ibuprofen and Piroxicam, probably with an amount_value of 1 and a unit of mg. |
DRUG_EXPOSURE | Quantity refers to the total amount of the compound. Use one record in the DRUG_EXPOSURE table for each compound. |
Example: 20% Ibuprofen of 30ml = 6mL, 1% Piroxicam of 30ml = 0.3mL | |
Ingredient dose= | Depends on the drugs involved: One of the use cases above. |
Ibuprofen dose = 6 x 1mg x 1000 = 6000mg |
|
Piroxicam dose = 0.3 x 1mg x 1000 = 300mg |
|
Note: The analytical side determines that the denominator for both ingredients in the DRUG_STRENGTH table is mg and applies the factor 1000 to convert between mL/g and mg. |