According to the CDISC Study Data Tabulation Model, what is a 'domain'?

In the context of the CDISC Study Data Tabulation Model (SDTM), a 'domain' refers to a collection of observations that share a common characteristic associated with a subject. This concept is fundamental in organizing and structuring clinical trial data effectively. Each domain typically covers a specific aspect of the study, such as demographic information, adverse events, or laboratory results, allowing for systematic analysis and reporting.

The defining feature of a domain is its cohesive nature—observations within a domain are tied together by their thematic relevance, facilitating data integrity and clarity in communication. For instance, the adverse events domain will contain all relevant data on adverse events experienced by participants in a study, which aids in understanding safety and tolerability.

This is distinct from other concepts; for example, a collection of unrelated observations does not exhibit the necessary linkage to represent a domain effectively. Similarly, a collection of task-specific data elements may be relevant for data management but does not convey the same breadth of meaning as a domain focused on a particular subject-related characteristic. Lastly, while the protocol may include various sections detailing study design, it is not synonymous with the structured data organization that a domain represents in the SDTM framework.