Help : Strata

The Strata of a Data-Field is a description of the nature of the data it describes. There are four categories:

• Primary - the key clinically/scientifically relevant data-fields;
• Derived - data which has been constructed by combining/processing values from one or more other data-fields;
• Supporting - data which is clinical/scientific in nature, but largely superceded by a Primary data-field;
• Auxiliary - data which describes the systems or processes used to acquire the data.

Note that the choice of strata can be somewhat subjective for some data-fields. Quick Search and the main Field Listing show only data-fields in the Primary and Derived strata, use of Full Search is advisable if you are selecting data-fields for a research application.