Why Are Certain SDTM Variables "Not for Use in Human Clinical Trials"?

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.

Reproductive Study Variables

Many of the domain variables not for use in human clinical trials are used in nonclinical reproductive studies. These types of reproductive studies are not conducted in humans.

Domains: Trial Reproductive Paths (TP), Trial Reproductive Stages (TJ), Subject Reproductive Stages (SJ)

Variables: Most have "Repro" in the label and are listed here.  Two others (FETUSID and –IMPLBL) do not have "Repro" in the label and are in the table below.

  • In Demographics:
    • Planned Repro Path Code (RPATHCD)
  • In Timing Variables:
    • Repro Phase (RPHASE)
    • Planned Repro Phase Day of Observation (RPPLDY)
    • Planned Repro Phase Day of Obs Start (RPPLSTDY
    • Planned Repro Phase Day of Obs End (RPPLENDY)
    • Actual Repro Phase Day of Observation (--RPDY)
    • Actual Repro Phase Day of Obs Start (--RPSTDY)
    • Actual Repro Phase Day of Obs End (–RPENDY)

Other Restricted Variables

Class or Domain Variable(s) Variable Label(s) Reason the variable is not for use in human clinical trials
Demographics SPECIES, STRAIN, SBSTRAIN Species, Strain/Substrain, Strain/Substrain Details In human clinical trials all subjects are of the same genus and species, Homo sapiens, and strain and sub-strain are not relevant.
Identifiers for all general observation class domains FETUSID Fetus Identifier This variable from nonclinical reproductive studies might seem applicable to human clinical trials, but the way it is used in nonclinical studies makes it inappropriate for use in human clinical trials. In non-clinical studies, FETUSID is used only to distinguish between findings about fetuses within a study subject for a particular assessment (i.e., test).  No attempt is made to use the same FETUSID for a particular fetus in different assessments.
Timing variable for all general observation class domains --NOMDY, --NOMLBL Nominal Study Day for Tabulations, Label for Nominal Study Day --NOMDY and --NOMLBL are reporting variables used to group records collected over multiple days under a single nominal study day for reporting purposes because the concept of visits or planned visit windows, as in human clinical trials, does not apply to nonclinical studies.
Timing variable for all general observation class domains --DETECT Time in Days to Detection The time to detection of an event or finding would be represented in an ADaM dataset in human clinical trials. ADaM is not generally used for nonclinical studies.
All general observation classes --USCHFL Unscheduled Flag In human clinical trials, unscheduled assessments are generally represented with a VISITNUM value that is not in the Trial Visits dataset. Since non-clinical studies do not use visit variables, --USCHFL is used instead of the visit-based mechanism for identifying unscheduled assessments.
Interventions --METHOD Method of Administration This variable is used in SEND to augment Route of Administration (--ROUTE), to distinguish between, for example, bolus and drip intravenous administration. In human clinical trials, the CDISC codelist Route of Administration Response (ROUTE) codelist includes values which allow these distinctions to be made without the use of an additional variable.
Interventions and Findings --RSTIND, --RSTMOD Restraint Indicator, Restraint Mode In non-clinical studies, subjects cannot cooperate in interventions or assessments, so may be restrained, physically or chemically, during interventions or assessments. The need to restrain subjects in human clinical trials is rare.
Findings --IMPLBL Implantation Site Label This variable is used in non-clinical reproductive studies to record findings about implantation sites at necropsy, so it is irrelevant for human clinical studies.
Findings --RESLOC Result Location of Finding In non-clinical reproductive studies. --RESLOC is used to specify the anatomical location of a finding within the area examined. In human clinical studies, the --LOC variable is sometimes used to represent the area examined and sometimes used to describe the location at which something is found. --RESLOC has not been adopted as the solution to this issue for human clinical studies.