Page History

Variables --DY, --STDY, and --ENDY represent the timing of observations in days relative to the reference start date in RFSTDTC where the value of:

• --DY is the relative day of the date populated in --DTC for the observation,
• --STDTC is the relative day of the date populated in --STDTC for the observation; and
• --ENDY is the relative day of the of the date populated in --ENDTC for the observation.

All relative day values will be integers and there will be no study day 0. The reference start date is considered day 1 and the study day value is increased by 1 for each date following the reference start date and decreased by 1 for each date prior to the reference start date, e.g.:

--DY = (date portion of --DTC) - (date portion of RFSTDTC) + 1 if --DTC is on or after RFSTDTC
--DY = (date portion of --DTC) - (date portion of RFSTDTC) if --DTC precedes RFSTDTC

Applicants may represent days relative to other applicant-defined reference dates beyond a reference period for a study. In such cases:

• Relative days will be represented in a nonstandard variable (NSV) in a --SUPP dataset associated with the domain. 
• All relative day values will be integers and there will be no day 0.
• The reference date is considered day 1 and the relative day value is increased by 1 for each date following the reference date and decreased by 1 for each date prior to the reference date.

• Variable --STRF represents the timing of observations relative to an applicant-defined reference period represented in RFSTDTC and RFENDTC, when relative timing such as "BEFORE", "PRIOR", "ONGOING"', or "CONTINUING" is collected instead of a date and is collected in relation to the applicant-defined study reference period.
• --STRF is used to identify the start of an observation relative to the sponsor-defined study reference period.
• Allowable values for --STRF are "BEFORE", "DURING", "DURING/AFTER", "AFTER", and "UNKNOWN". Although "COINCIDENT" and "ONGOING" are in the STENRF codelist, they describe timing relative to a point in time rather than an interval of time, so are not appropriate for use with --STRF variables. It would be unusual for an event or intervention to be recorded as starting "AFTER" the study reference period, but could be possible, depending on how the study reference period is defined in a particular study.

• Variable --STRF represents the timing of observations relative to an applicant-defined reference period represented in RFSTDTC and RFENDTC, when relative timing such as "BEFORE", "PRIOR", "ONGOING"', or "CONTINUING" is collected instead of a date and is collected in relation to the applicant-defined study reference period.
• --ENRF is used to identify the end of an observation relative to the sponsor-defined study reference period.
• Allowable values for --ENRF are "BEFORE", "DURING", "DURING/AFTER", "AFTER" and "UNKNOWN". If --ENRF is used, then --ENRF = "AFTER" means that the event did not end before or during the study reference period. Although "COINCIDENT" and "ONGOING" are in the STENRF codelist, they describe timing relative to a point in time rather than an interval of time, so are not appropriate for use with --ENRF variables.