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Outpatient visits that last more than one day

CDM Builders
#1

@Christian_Reich

Hello!
I have a question about outpatient visits.
In the source table (EHR data) we have flag for outpatient/inpatient visits.
But some outpatient visits (flag = ‘Outpatient’ in the source) last more than one day (i.e. discharge date - date of admission > 0)
In most such cases it is 1 day (for 1 day it could be for example situation like this: patient admitted into ER 01.01.2017 23:30:00 and went home 02.02.2017 01:00:00). But in some cases it could be 30 or 29 or 2 etc. days

For now, we have 3 ideas how to treat visits with (discharge date - date of admission) > 0 for OMOP:

  1. treat as inpatient visits in OMOP although in source data they have ‘Outpatient’ flag
  2. treat as outpatient visits in OMOP for (discharge date - date of admission) <= 1 and as inpatient visits for (discharge date - date of admission) > 1 although in source data they have ‘Outpatient’ flag
  3. treat as outpatient visits in OMOP because in source data they have ‘Outpatient’ flag in spite of (discharge date - date of admission) > 0

If any of these ideas is correct?

Thank you in advance.

#2

@Alexandra_Orlova:

Hey! There is a whole OHDSI community. Not just me! :smile:

ER is not an outpatient visit, but an ER visit. Outpatient visits are visits to doctor’s offices, doctor’s practices, ambulatories, polyclinics, or whatever they are called in the different healthcare systems. Usually, these places close in the evening. Really sick patients get referred to a hospital or ER (ED, A&E and all the other local names), where they are put into bed.

Which might be what you are looking at: Patients got the Outpatient flag because they went to an ambulatory doctor, but ended up staying in the hospital. Therefore, you may want to create two visits: One for the initial one (with the flag), and one for the subsequent one that kept them overnight.

But OMOP outpatient visits have start_date=end_date. The THEMIS Focus Group 2 will codify all these situation.

#3

Thank you for quick response!

In our case outpatient flag is populated in the bill for patient. Patient with outpatient flag was not admitted as inpatient but in fact he stayed overnight in hospital (for discharge date - date of admission > 0) for some days. Is it correct to treat such visit as inpatient for OMOP?

Should start_date = end_date for ER visits (visit_concept_id = 9203 (Emergency Room Visit))? From example above (for 1 day it could be for example situation like this: patient admitted into ER 01.01.2017 23:30:00 and went home 02.02.2017 01:00:00) could we start_date populate with 01.01.2017 and end_date with 02.02.2017? Or in this case we have to populate start_date and end_date with one date 01.01.2017 or 02.01.2017?

#4

@Alexandra_Orlova:

Hm. I am not 100% sure what the rules are, but usually inpatients have to be admitted: They need a bed. ER patients might just sit around or lie on a stretcher, so that could stretch more than one day, like in your example. Outpatients cannot be overnight.

#5

We have seen in some of the data sources, they do not have any information
about visit_type, and its very difficult to identify IP and OP visits. We
have tried to implement the same rule if start_date =end_date we consider
them as Outpatient visits and if the datediff is >= 1 day we treat them as
inpatient visits. Whichever data source we have these visit_types
available, we tag them straight forward as IP or OP, but if there is no
flag available, we use the SD=ED or >= 1 day logic for flagging visits.

#6

I’m not sure what source data you are working with, but if it revolves around U.S. medical claims, then the "outpatient flag’ you mention could indicate that the medical visit was paid for by the patient’s outpatient benefits and have nothing to do with where the patient was actually seen. That is why you are seeing claims that last longer than 1 day. Medicare has a number of resources to help patients navigate their benefits - https://www.medicare.gov/Pubs/pdf/11435.pdf. But, basically, if the physician does not admit you, you are not covered under inpatient benefits. Hospitals usually call this “under observation”. So the patient is sitting in a hospital bed for multiple days under “observation” - where their outpatient coverage is being used. In this instance, that “outpatient flag” may be set to yes.

There are also other reasons why you can have an outpatient claim last multiple days. There are certain CPT/HCPCS codes that require physicians to bill using multiple days. The most common one is for dialysis billing. Physician oversight is billed one HCPCS code per month with a date range from the first of the month to the end of the month (example: cpt 90960 1/1/2017-1/31/2017).

For more information about “outpatient” visits with multiple days, you can see this thread here: Visit_occurrence, Outpatient and Long Term care visits.

So, depending on how to you define “outpatient”, this “outpatient flag” may not be reliable for you.

#7

Thank all for responses!

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