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What is the mean of 'all events from outside observation period'?


(panpan) #1

dear all,
when I use the atlas to construct a cohort, in the inclusion Criteria, I find there is an option like the picture, what is the mean of the option in the box? and how to include a person using it?
thank you very much!


(Eldar Allakhverdiiev) #2

Hi @pandamiao,
Due to OMOP specification any person can have more than one observation period. By default any inclusion criteria are being searched only inside observation period in which the initial event exists. (i.e if there is a person with 2 periods, and initial event is met in the second one, the first period is out of scope for inclusion criteria. If you’d like to allow records from the first period to be part of inclusion criteria you should use this checkbox then.)

Another use case: there are some events that can be outside of observation period at all ( at least Observations, but some Conditions as well). If you decide to trust such records - use this button as well.


(panpan) #3

thank you very much @Eldar, I get it. And another question, because there is only one observation_period for one person in our database, I am a little confused about one person have more than one observation period. can you give me an example? thank you very much


(Gyeol Song) #4

Hi @pandamiao,

In a typical EMR/EHR based CDM DB, there would be one observation_period per patient with his/her first record in the hospital being the observation_period_start_date and his/her last record in the hospital being the observation_period_end_date.

However, in the cases of claims data, a patient may change between health insurance payers, resulting in multiple oberservation_periods. Say I am covered by payer A from 2008 to 2010 and change to payer B from 2011 to 2013 and then return to payer A from 2014 to 2016. If payer A decides to convert its claims data into the OMOP CDM, my data would have two observation_periods: one from 2008 to 2010, the other from 2014 to 2016.

Hope my explanation is sufficient.


(panpan) #5

Very clear, thank you very much @gyeol99


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