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Naming Observation source_value

I am wondering if I can write whatever I name it for ‘observation source value’.
For a survey question asking for Smoking history, I used ‘Concept id’ 43054909 (Tobacco smoking status). And for the answers, I used four ‘value_as_concept_ids’. However, because there aren’t OMOP codes that specify the period of smoking, in this case, less than or more than 12 months, I just used concept id 4310250 for ex-smoker and specified the period in ‘Observation_source_value’. I wrote ex-smoker<12months. Can I do that?

The _source_value fields can indeed be used how you see fit. The main purpose of these fields is for your own ‘traceability’ of what code in the source was mapped to what target concept. Useful e.g. in ETL quality control. But _source_value are never used for standardised OHDSI analytics.

That said, in your example I would actually take a different approach:

field value
observation_concept_id 43054909
observation_source_value SMOKING_HISTORY
value_as_concept_id 4310250
value_as_string ex-smoker(< 12months)

(reasoning: the observation_source_value is the original value that was mapped to observation_concept_id, value_as_string holds the ‘categorical value of the Result of the Observation’ according to the Observation table documentation)

Thank you so much for your help! I agree with your approach to this and cleared my confusion.!

Best Regards,