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Drug_exposure Quantity

Question 1:
I’ve got a patient given 1000 mg of the drug ACETAMINOPHEN 500 MG PO TABS (concept_id:19020053) (concept_class_id: Clinical Drug). In the drug_strength table, this has an Amount_value of 500 and an Amount_Unit_concept_id of 8576 (mg).

In the drug_exposure.quantity field, do I store the number of tablets (2) or the amount in milligrams (1000)?

Question 2:
I’ve got a Clinical Drug of HYDROCODONE-ACETAMINOPHEN 10-325 MG PO TABS (concept_id: 40162511). According to How to Calculate Drug Dose drug_dose.knit, this should go in the drug_exposure table as two entries (HYDROCODONE and ACETAMINOPHEN). These would then be at the Ingredient level. But the advice for concept_class_id is to store it at the level with the most information (ie clinical drug) and only use Ingredient as a last resort.

Do I store HYDROCODONE-ACETAMINOPHEN 10-325 MG PO TABS with a Quantity of 1, or two record with a value of 325 and 10, respectively?

1 Like

Hello @roger.carlson ,

#1: Per the conventions: “For clinical drugs with fixed dose forms (tablets etc.) the quantity is the number of units/tablets/capsules prescribed or dispensed (can be partial, but then only 1/2 or 1/3, not 0.01).”

#2: I am not quite sure what calculating a drug dose has to do with your question. If you have a clinical drug concept_id, then put that in drug_concept_id and put the quantity, per the convention above, in the quantity field. Don’t divide the drug into ingredients and add to the drug_exposure table. There isn’t a need to do this and some researchers want to know if the person had a combo drug. I didn’t click your link, but calculating a drug dose is for researchers wanting to know how much of drug A did a person receive when they took a combo drug, not for the ETL to worry about.

The link I posted is from the very bottom of the convention for Quantity

Please see how to calculate drug dose for more information.

It is unclear to me whether this is for the analytic side or the ETL side.

Ah, I see it now. It’s posted at the bottom of the ETL conventions section. Definitely ambigious. It’s for the researcher trying to create dosing information from drug exposure records. Not how to ETL the source records. We should clarify the wording. Can you create an issue here?

That one (except the name of the concept is “acetaminophen 325 MG / hydrocodone bitartrate 10 MG Oral Tablet”). If the quantity really is one tablet (like in a hospital EHR) then the quantity is 1. For prescriptions, you have usually higher quantities or days_supply information. Put that in.

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Okay, that takes care of ‘pill’ type drugs. But what about solutions? I have some additional scenarios

Question 3:
CONCEPT_CLASS_ID = ‘Quant Clinical Drug’
SIG = 50

Am I correct that the Quantity would be
QUANTITY = 50/(0.1 / 2) = 1000

Question 4:
CONCEPT_CLASS_ID = ‘Quant Clinical Drug’
SIG = 100

QUANTITY = 100/(57000 / 75) = 0.13157894736842105

I’ve also got some DOSE_UNIT_SOURCE_VALUEs like ‘mL/hr’, ‘Units/kg/hr’, ‘g/hr’, ‘mg/min’, etc. And some truly bizarre ones like ‘mg/m2’ (FLUOROURACIL 500 MG/10ML IV SOLN (82504:FLUOROURACIL 500 MG/10ML IV SOLN))

Do I need to handle the timing issue? eg. hr, min, etc?

Are you still discussing MAR or administered drug data? You have Epic data, correct? Clarity? Do you have a quantity field?

#3: All the SIG says is 50? You could guess that 50 mcg is the quantity a person received (if MAR/drug admin data). And 50 mcg is a reasonable dose for a person. But if the person is receiving a continuous iv infusion, then maybe the person receives 50 mcg an hour? What other attributes do you have at the source for this record?

Your math to find quantity is combining two different units. You have mcg at the source and the Drug Strength numerator is in mg. 1000 is not the correct answer for quantity.

With this example you do not need to use the Drug Strength table because your source units align with the units in the Drug Strength table. “If liquid, quantity stands for the total amount dispensed or ordered of ingredient in the units given by the drug_strength table.”

#4 Again, SIG = 100 isn’t enough information. Without seeing all attributes of the source data and not knowing anything about the source data, I would guess the person received 100 ml of the drug based on 1. This is an acceptable dose 2. This is only an “administered by a trained provider in a healthcare setting”. Per the conventions, you need to convert the 100 ml to amount of mg the person received

Yes, we have Epic. The Quantity is null for hospital encounters. So as far as I can see, I have to infer the quantity from the SIG (which is just a number) and the Dose_unit.

I’d be very interested in where other Epic sites are getting their quantity for hospital encounters.