SNOMED CT

The Systematized Nomenclature Of Medicine - Clinical Terms (SNOMED CT) is the most comprehensive healthcare terminology and is used in more than 80 countries worldwide. The hierarchically structured terminology contains over 350,000 clinical concepts grouped into 19 categories at the highest level.

Germany has been a member country of SNOMED International, the publishing organization, since January 2021, so German users have access to the terminology via a free license, which can be accessed using a web-based search function. SNOMED CT is primarily used as a complement to ICD-10-GM to describe diseases and complaints.

One key advantage of SNOMED CT is its vast vocabulary, which encompasses not only diagnoses (as part of the disorder hierarchy) but also symptoms (findings), and other psychosocial factors (event, social context, etc.).

Identification of Questionnaire	Score	Items	Answers
Assessment Scale	Observable entity	Disorders	Qualifier values
		Observable Entities	Findings

This level of granularity makes it possible to encode the nuanced aspects of psychiatric instruments, such as individual questionnaire items, symptoms measured, and context-specific variables.

Fig. Second Item of BDI-II - German Modification with SNOMED CT code examples

Another strength of SNOMED CT is its rich hierarchical structure and relationships between concepts, which allow for advanced querying and data integration. For instance, psychiatric symptoms or findings coded in SNOMED CT can be linked to broader diagnostic categories or treatment plans, facilitating interoperability in electronic health records (EHRs).

Fig. SNOMED CT codes for psychiatric questionnaires as screenshots from the online database (Source: SNOMED browser)

In SNOMED CT it is possible to code both psychiatric questionnaires and scores for the questionnaires. However, more often than not no distinction is made here as to which questionnaires are involved, only the information as to which disorder is involved.