Page History

In general observation class domains, timing variables are used to represent the actual timing of observationsthe dates and times (when appliable) observations were collected are represented in variable --DTC. In interventions and events class domains, variable --STDTC is used to represent the start dates and times (when applicable) of interventions and events. Variable --ENDTC is used in all general observation class domains to represent the end date and time (when applicable) of the observation.

The variables used to describe time can vary between point-in-time observations (e.g., body weights) and duration-based observations (e.g., food consumption).

...

Most domains, especially Findings domains, have basic timing variables expressing the actual timing of the observation. The variables used to describe time can vary between point-in-time observations (e.g., body weights) and duration-based observations (e.g., food consumption).

Actual timing for point-in-time observations is expressed through the following variables:

• --DTC is the date when the observation occurred. Depending on the precision of the date, this can represent just the date (e.g., 2010-12-31) or a date and time (e.g., 2010-12-31T08:00). The --DTC variable is expected for many Findings domains.
• --DY is the study day when the observation actually occurred, relative to the sponsor-defined RFSTDTC variable in the Demographics (DM) domain.

These variables are shown in Figure 4471A.

...

Some observations may be associated with an interval of time (e.g., a finding evaluated over 2 hours). The following variables enable the definition of these ranges:

• --ENDTC is the end date of the range of time when the observation occurred. Depending on the precision of the time, this can represent just the date (e.g., 2010-12-31) or a date and time (e.g., 2010-12-31T08:00).
• --ENDY is the end day of the range of time when the observation occurred, relative to the sponsor-defined RFSTDTC variable in the DM domain.

In these cases, the --DTC/--DY variables are used to define the start of the interval.

...

These variables are shown in Figure 4471B, in a case where an observation spanned 2 days

...

...