observation

FHIR AllergyIntolerance records patient allergies and intolerances. OMOP has no dedicated allergy table, so allergies are stored in the observation table with allergy-specific SNOMED concepts. One AllergyIntolerance maps to one observation row. Status filtering excludes inactive/resolved allergies and entered-in-error/refuted records.

When a DiagnosticReport's LOINC code resolves to an OMOP concept with domain_id = Observation, the report produces one or more observation rows. This applies primarily to clinical document types -- history and physical notes, discharge summaries, evaluation and plan notes, consultation notes -- where the LOINC code represents a document class rather than a quantitative measurement or procedure. Each conclusionCode entry generates a separate row. This is the most frequently hit domain for DiagnosticReport resources in real-world EHR data (clinical notes are far more common than lab panel-level reports).

Qualitative clinical findings: social history, lifestyle factors, survey responses, activity data. One FHIR Observation (or one component) maps to one OMOP observation row. Also receives data from AllergyIntolerance and FamilyMemberHistory.