KB Search

When an implementer is working how to represent data for a study, they first consult the SDTMIG and SDTM to find the appropriate standard variable. If no appropriate standard variable is found, the SDTMIG directs them to create a supplemental qualifier, also called a non-standard variable.

In an events or interventions domain, the variable --PRESP = "Y" can be used to indicate that the value in the topic variable (--TERM or --TRT) was pre-specified. However, --PRESP is not a variable that is allowed in findings domains.

In some cases, the reason for the restriction is fairly obvious, but in other cases, understanding the reason requires understanding the differences between how human clinical trials and nonclinical trials are conducted.