Hi, We were wondering what the recommended practice is if we want to note that a drug exposure is for an order that was “as needed” (i.e., PRN)? It was not apparent that the CDM has a place to note ‘PRN’. We have been concatenating the string ‘PRN’ to the SIG string so that we could filter PRNs as needed in certain queries but don’t know if there is a better approach.
I am confused. Why is p.r.n. not a string you would put into the sig field?
We may want to think about normalizing all that stuff, and instead of open string have concepts for all of them. Do you have a good list of sigs?
@Christian_Reich - we do have as bunch of SIGs but the drug data we work with (dispensing and medication administration records) all note ‘p.r.n’ in a structured field. What I was saying is that we have been concatenating ‘p.r.n’ to the SIG for those drug records that are noted as such in the structured field because we don’t know where else to put it. The SIGs themselves talk about ‘p.r.n’ in a variety of ways so our approach at least ensure that we can filter by like '%p.r.n%' but, I think having a new field in the CDM drug_exposure table (or some other way to indicate PRN that does not involve a string match) would be a better approach
I am still not getting it. If the doc writes p.r.n. then there is no other sig. It’s “as needed”. What are you concatenating?
The dispensing record from the system that tracks pharmacy dispensing will note a value of ‘true’ in the PRN data field. In those cases, we have been concatenating the string ‘PRN’ to the SIG (see why above). This is necessary because 1) we need to drop PRN drugs from certain kinds of analyses because they do not match actual administration and 2) the SIG lines themselves do not report the prn status consistently.
Sounds like you got it down. If the PRN field is checked write “p.r.n.” into the DRUG_EXPOSURE.sig field. If not, take whatever you have in the SIG (maybe with some cleaning up).
In the long run, we should conceptualize the content of sig anyway. These string acrobatics are a CDM no-no. I’ll add something to the list of things.