opened 04:29PM - 15 Jul 19 UTC
**PROBLEM**: Allergies.
There are ambiguities on:
1. How to store allergies… to OMOP CDM;
2. How to link allergic reactions and the associated drugs/allergens.
**FORUM:**
https://forums.ohdsi.org/t/observation-event-id-to-link-allergic-reactions/7354
https://forums.ohdsi.org/t/put-allergy-in-omop/2737/9
https://forums.ohdsi.org/t/how-to-encode-allergy/2024/4
https://forums.ohdsi.org/t/new-fact-relationship-relationship-id/4937/7
**CURRENT SOLUTIONS DISCUSSED:**
1. Drugs/allergens can be stored to OBSERVATION table to the column value_as_concept_id with one of the following observation_concept_id's = 439224 (Drug allergy) or 4169307 (Allergy to substance)
2. To store allergic reactions, 2 cases possible:
a) If the condition_start_date is given, then, it can be populated to CONDITION_OCCURRENCE table to condition_concept_id column;
b) If instead of the start_date there is an input date, then, it can be populated to OBSERVATION table to value_as_concept_id with observation_concept_id 4166257 (Allergic reaction to drug) or 441488 (Adverse reaction to substance).
3. To link allergic reactions and the associated drugs/allergens, 2 cases possible:
a) Through observation_event_id column from OBSERVATION table. A record with an associated allergen from OBSERVATION table can be linked back to a record with an associated allergic reaction (to condition_occurrence_id or to observation_id);
b) Through FACT_RELATIONSHIP table. Currently, there are no valid concepts to be used to link allergic reactions and the associated drugs/allergens.