Episode

Epic equivalent: No direct equivalent — these are explicitly constructed clinical periods

The episode table defines higher-level clinical periods — pregnancies, disease episodes, treatment regimens, or care bundles — that group multiple events (conditions, procedures, drugs) under one umbrella. Unlike condition_era (which is auto-derived from code frequency), episodes are explicitly curated during ETL or by researchers.

Each episode can link to its contributing events through the episode_event table.

Field Reference

Field reference (click to expand)

OMOP Field	What It Captures
episode_id	Unique identifier
person_id	Links to the patient
episode_concept_id	Type of episode (e.g., "Pregnancy", "Chemo Regimen")
episode_start_date	Start of the episode period
episode_end_date	End of the episode period
episode_parent_id	Optional link to a parent episode (supports nesting)
episode_number	Ordinal (e.g., Chemo Cycle 1, 2, 3)
episode_object_concept_id	How the episode was defined (rule-based, registry, etc.)

What to Watch For

Common pitfalls

Rarely populated unless curated

Requires specific logic — pregnancy algorithms, oncology pipelines, or manual research definitions. Check what's available before building on this table.

Not generated by default ETL

Unlike condition/drug eras, episodes require intentional construction.

Can span multiple domains

A single episode may encompass conditions, procedures, drugs, and measurements. Use episode_event to see the full picture.

Research Patterns

Question	Tables Involved
Pregnancy outcomes (live birth vs. miscarriage)	episode (pregnancy) + outcome logic
Time from diagnosis to treatment in cancer	episode (oncology) + linked events via episode_event
Depression episodes with remission/recurrence tracking	episode_concept_id (depression) + episode_number
Chemotherapy regimen duration	episode (chemo) start/end dates
Surgical complication rates by episode type	episode + episode_event linking to conditions and procedures