Vocab. Read - OHDSI/Vocabulary-v5.0 GitHub Wiki

Read is a clinical terminology system used by the UK National Health Service (NHS) to record patient information in healthcare IT systems. Read used to be a standard terminology in the UK until NHS switched to SNOMED CT.

Read Codes cover a wide range of patient care topics, including clinical signs and symptoms, laboratory tests and results, diagnoses, procedures, occupation, social circumstances, ethnicity, and religion.

All Read information is obtained from the following sources:

• Information Services Division (ISD) supported by the National Health Service (NHS) Website
• NHS Data migration portal: mappings from Read to SNOMED

The procedures for transforming Concepts from the source to the OMOP Standard Vocabularies can be found on the OHDSI GitHub.

Concept names are assigned based on the length of the descriptions. If the description_long field is filled in the source, it is used as the name. If that field is not populated but the description field is, then the term in the description field becomes the concept name. If neither of the first two fields has a name, we use the description_short field.

Concept codes are a concatenation of two source fields: readcode and termcode.

Domains are assigned based on the domain of the target standard concept. If the mapping changes to a concept with a different domain or the target concept changes its domain, the previous domain is combined with the new one, for example, "Condition/Procedure."

All Read concepts are in the “Read” concept_class_id.

All concepts are Non-Standard.

There are no internal relationships between Read codes. The only available relationships are mappings to the standard codes (eg. ‘Maps to’, ‘Maps to value’)