We are working on a use case where we would like to capture visits that were scheduled but ultimately not attended by the patient. These missed appointments are recorded in our source system and can provide useful information about patient adherence to treatment or follow-up protocols.
We were wondering how this type of information should be represented in the OMOP CDM. Specifically:
Is there a recommended way to record a visit that was scheduled but did not take place?
Should it be included in the visit_occurrence table with a special concept ID or status?
Or is there another table or mechanism better suited for this kind of data?
Any guidance or examples from the community would be greatly appreciated.
Is there a recommended way to record a visit that was scheduled but did not take place?
Generally, events that are known NOT to have happened are not recorded in OMOP tables at all, per convention. There is an Observation domain concept for scheduling a future visit, but I am not sure how to record the visit date value – maybe convert to POSIX time and put it into observation.value_as_number field? Retrieval turns awkward.
Should it be included in the visit_occurrence table with a special concept ID or status?
This should be avoided. Negation of event in status fields is not supported, because convention is no event => no record.
Or is there another table or mechanism better suited for this kind of data?
I think OMOP way of doing this would be recording scheduling of a visit for a certain date by using the aforementioned “scheduling appointment” Observation concept with prospective date as either numeric or text verbatim value, and then joining negatively with the visit_occurence table.