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Missing visit start date

I am new to CDM,

I am working on EHR data and found that for some patient visit start date is missing.

Can I use visit_start_date as 1800-01-01 as default?

I have looked into some ETL work on Github, they have used 1900-01-01 as default date.

I don’t think so, @Dipak_Yadav. That solution gets you around the database constraints, that’s all. From an analytics perspective it is horrible, plus it violates a visit shouldn’t be outside the observation period, which then also would have to start in the 1800s. Sorry.

You could try guessing from the other data when the visit started. If that is impossible you should drop the visit entirely.

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