Supplemental common data element

A supplemental common data element (CDE) is a data element which is commonly collected in clinical research studies but whose relevance depends upon the study design (i.e., clinical trial, cohort study, etc.) or type of research involved.

Examples of Supplemental CDEs are the Epilepsy CDEs related to electroencephalogram (EEG) that are only relevant to epilepsy studies that use EEG for diagnostic purposes and the Stroke CDEs related to administration of Tissue Plasminogen Activator (tPA) that are relevant to acute ischemic stroke studies but not relevant to intracerebral hemorrhage (ICH) studies.

Sourced From
National Institute of Neurological Disorder and Stroke (NINDS): Classifications of Data Elements for a Particular Disease