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Glossary

OMOP / OHDSI

OMOP CDM
Observational Medical Outcomes Partnership Common Data Model — a standardised schema for observational health data, maintained by OHDSI.
OHDSI
Observational Health Data Sciences and Informatics — the open-science community that maintains OMOP CDM and the surrounding tooling.
Athena
The OHDSI vocabulary download portal at athena.ohdsi.org.
Rabbit-in-a-Hat
An OHDSI tool for designing source-to-CDM mappings visually. The ETL Engine consumes its JSON output directly.
Usagi
An OHDSI tool for mapping source codes to OMOP standard concepts. The engine reads its CSV output via the UsagiMap rule.
WhiteRabbit
An OHDSI tool that produces the scan reports consumed by Rabbit-in-a-Hat.

DSL

Rule chain
A sequence of rules executed top-down on a single field, field-to-field mapping, or CDM-table input.
Mapping rule
A rule that transforms one input value into one output value. Most rules of the form AsX, XFromDate, etc. are mapping rules.
Aggregating rule
A rule that takes any number of inputs and produces exactly one output. Add, Min, Use, Selector, etc. are aggregating rules.
Table rule
A rule placed on a CDM table itself (rather than on a field), affecting how rows enter the table. DependOn, Normalize, Join are examples.
Filter rule
A rule that decides which rows pass through, based on a grouping key. First and Last are the only filter rules currently.
Virtual field
A field that exists only inside the engine, not in the CDM database. Declared with field: in a CDM-table Comments field. See Virtual Fields.
Multi-sized result
A rule output that produces more than one record per input row. Marked with the [] or [N] suffix on the rule.
Conditional chaining
The || operator joining rules into a fallback sequence: try the first, fall through to the next on failure. See Conditional Chaining.