SE Assumptions

The SE domain allows the submission of data on the timing of the trial elements a subject actually passed through in their participation in the trial. 

1. For any particular subject, the dates in the SE table are the dates when the transition events identified in the TE table occurred. Judgment may be needed to match actual events in a subject's experience with the definitions of transition events (i.e., events that mark the start of new elements) in the TE table; actual events may vary from the plan. 
2. Judgment will also have to be used in deciding how to represent a subject's experience if an element does not proceed or end as planned. 
3. If the applicant decides that the subject's experience for a particular period of time cannot be represented with one of the planned elements, then that period of time should be represented as an unplanned element. The value of ETCD for an unplanned element is “UNPLAN” and SEUPDES should be populated with a description of the unplanned element.
4. The values of SESTDTC provide the chronological order of the actual subject elements. SESEQ should be assigned to be consistent with the chronological order. Note that the requirement that SESEQ be consistent with chronological order is more stringent than in most other domains, where --SEQ values need only be unique within subject.
5. When TAETORD is included in the SE domain, it represents the planned order of an element in an arm. This should not be confused with the actual order of the elements, which will be represented by their chronological order and SESEQ. TAETORD will not be populated for subject elements that are not planned for the arm to which the subject was assigned. Thus, TAETORD will not be populated for any element with an ETCD value of “UNPLAN”. TAETORD also will not be populated if a subject passed through an element that, although defined in the TE dataset, was out of place for the arm to which the subject was assigned.
6. For subjects who follow the planned sequence of elements for the arm to which they were assigned, the values of EPOCH in the SE domain will match those associated with the elements for the subject's arm in the TA dataset. The applicant will have to decide what value, if any, of EPOCH to assign SE records for unplanned elements and in other cases where the subject's actual elements deviate from the plan. 
7. Because there are, by definition, no gaps between elements, the value of SEENDTC for one element will always be the same as the value of SESTDTC for the next element.
8. Note that SESTDTC is required, although --STDTC is not required in any other subject-level dataset. The purpose of the dataset is to record the elements a subject actually passed through. If it is known that a subject passed through a particular element, then there must be some information (perhaps imprecise) on when it started. Thus, SESTDTC may not be null, although some records may not have all the components (e.g., year, month, day, hour, minute) of the date/time value collected.
9. The following identifier variables are permissible and may be added as appropriate: --GRPID, --REFID, --SPID.
10. Care should be taken in adding additional timing variables: 
    1. The purpose of --DTC and --DY is to record the date and study day on which data was collected. Elements are generally “derived” in the sense that they are a secondary use of data collected elsewhere; it is not generally useful to know when those date/times were recorded.
    2. --DUR could be added only if the duration of an element was collected, not derived.
    3. It would be inappropriate to add the variables that support time points (--TPT, --TPTNUM, --ELTM, --TPTREF, and --RFTDTC), because the topic of this dataset is elements.