OHDSI Home | Forums | Wiki | Github

How does one associate multiple datetime stamps with a lab result?

For each lab result, there are at least two DateTime stamps of importance for retrospective review: when the sample was drawn and when the results became available. Further differentiating between preliminary and final results would be nice too.

I understand that convention is to use measurement_datetime for the draw time. Is there a standard, preferred, or recommended way to include the result time(s)?


If you have a strong use case for an OHDSI network study, you could petition the CDM WG to add this field to the Measurement table. If you need this for local use, I would just add a field, something obvious like ‘lab_result_datetime_x’, to the Measurement table.

1 Like


Actually, this already works. The blood draw is a Procedure called Phlebotomy. The procedure to derive the measurement is not a Procedure in the OMOP sense, since it is not performed on the patient. The result is the Measurement. Only thing you are missing is the connection between the two. You have FACT_RELATIONSHIP for that.

I wonder what the use case is, though. Maybe a quality metric for institutions how quickly they turn around lab tests?

1 Like

Thank you.

This is what I thought most likely. The problem that I saw with it is that I understand by convention measurement.measurement_datetime refers to draw time, not result time

Now I need to determine how and/or whether we can get the draw procedure added to the data we obtain.

This is for a large federally-funded initiative the database of which will ultimately be publicly available.

Hi Melanie. Thanks for the suggestion.

I agree that if I were creating a local database for a project, adding that field would be the quick and easy solution.

However, it’s for a massive initiative that will ultimately provide a publicly available (de-identified) database.

I will consult with others on the team as to whether they agree that we should petition the CDM WG.


1 Like