Timing Variables

Timing variables are copied from the SDTM and derived within ADaM. Common timing variables are provided in this section. If other timing variables are collected in SDTM and pertinent for analysis, these should be included in ADaM. Additional timing variables, such as those for period start and end dates, can be included. For more details on timing variables, see Timing Variables for BDS Datasets.

Variable Name	Variable Label	Type	Codelist/ Controlled Terms	Core	CDISC Notes
--STDTC	Start Date/Time of Observation	Char	ISO 8601 datetime or interval	Cond	Copied from XX.–STDTC Conditional on whether start date is pertinent for study and is populated in SDTM This variable label differs depending on the SDTM domain. AESTDTC is required for adverse event data.
ASTDT	Analysis Start Date	Num		Cond	Created from converting XX.--STDTC from character ISO 8601 format to numeric date format, applying imputation rules if specified in the statistical analysis plan (SAP) or metadata Conditional on whether start date is pertinent for study and is populated in SDTM. Required for adverse event data.
ASTTM	Analysis Start Time	Num		Cond	Created from converting XX.--STDTC from character ISO 8601 format to numeric time format, applying imputation rules if specified in the SAP or metadata Conditional on whether start time is pertinent for study and is populated in SDTM
ASTDTM	Analysis Start Datetime	Num		Cond	Created from converting XX.--STDTC from character ISO 8601 format to numeric datetime format, applying imputation rules if specified in the SAP or metadata Conditional on whether start datetime is pertinent for study and is populated in SDTM
ASTDTF	Analysis Start Date Imputation Flag	Char	(DATEFL)	Cond	The level of imputation of analysis start date. Imputation flags are described in ADaMIG v1.2 Section 3.1.3, Date and Time Imputation Flag Variables. Conditional on whether ASTDT (or the date part of ASTDTM) was imputed
ASTTMF	Analysis Start Time Imputation Flag	Char	(TIMEFL)	Cond	The level of imputation of analysis start time. Imputation flags are described in ADaMIG v1.2 Section 3.1.3, Date and Time Imputation Flag Variables. Conditional on whether ASTTM (or the time part of ASTDTM) was imputed
--ENDTC	End Date/Time of Observation	Char	ISO 8601 datetime or interval	Cond	Copied from XX.--ENDTC Conditional on whether end date is pertinent for study and is populated in SDTM This variable label differs depending on the SDTM domain. AEENDTC is required for adverse event data.
AENDT	Analysis End Date	Num		Cond	Created from converting XX.--ENDTC from character ISO 8601 format to numeric date format, applying imputation rules if specified in the SAP or metadata. If both ASTDT and AENDT are populated then ASTDT must less than or equal to AENDT. Conditional on whether end date is pertinent for study and is populated in SDTM. Required for adverse event data.
AENTM	Analysis End Time	Num		Cond	Created from converting XX.--ENDTC from character ISO 8601 format to numeric time format, applying imputation rules if specified in the SAP or metadata Conditional on whether end time is pertinent for study and is populated in SDTM
AENDTM	Analysis End Datetime	Num		Cond	Created from converting XX.--ENDTC from character ISO 8601 format to numeric datetime format, applying imputation rules if specified in the SAP or metadata. If both ASTDTM and AENDTM are populated then ASTDTM must less than or equal to AENDTM. Conditional on whether end datetime is pertinent for study and is populated in SDTM
AENDTF	Analysis End Date Imputation Flag	Char	(DATEFL)	Cond	The level of imputation of analysis end date. Imputation flags are described in Section 2.9.3.3, Date and Time Imputation Flag Variables. Conditional on whether AENDT (or the date part of AENDTM) was imputed
AENTMF	Analysis End Time Imputation Flag	Char	(TIMEFL)	Cond	The level of imputation of analysis end time. Imputation flags are described in Section 2.9.3.3, Date and Time Imputation Flag Variables. Conditional on whether AENTM (or the date part of AENDTM) was imputed
ASTDY	Analysis Start Relative Day	Num		Cond	The number of days from an anchor date (not necessarily DM.RFSTDTC) to ASTDT Example derivation: ASTDT - ADSL.TRTSDT + 1 if ASTDT >= ADSL.TRTSDT, else ASTDT - ADSL.TRTSDT if ASTDT< ADSL.TRTSDT This variable may instead be copied from --STDY. Conditional on whether analysis start relative day is pertinent to the study. Required for adverse event data.
--STDY	Study Day of Start of Observation*	Num		Perm	Copied from XX.--STDY ASTDY may differ from --STDY due to date imputation and the option in ADaM to use a reference date other than SDTM’s RFSTDTC. Including XX.--STDY in addition to ASTDY adds traceability. For SubClass ADVERSE EVENT, conditional on whether the AESTDY variable is in the SDTM AE dataset
AENDY	Analysis End Relative Day	Num		Perm	The number of days from an anchor date (not necessarily DM.RFSTDTC) to AENDT Example derivation: AENDT - ADSL.TRTSDT + 1 if AENDT >= ADSL.TRTSDT, else AENDT - ADSL.TRTSDT if AENDT < ADSL.TRTSDT This variable may instead be copied from --ENDY. If both ASTDY and AENDY are populated then ASTDY must be less than or equal to AENDY. Required for adverse event data.
--ENDY	Study Day of End of Observation*	Num		Perm	Copied from XX.--ENDY AENDY may differ from --ENDY due to date imputation and the option in ADaM to use a reference date other than SDTM’s RFSTDTC. Including XX.--ENDY in addition to AENDY adds traceability. If both --STDY and --ENDY are populated then --STDY must be less than or equal to --ENDY For SubClass ADVERSE EVENT, conditional on whether the AEENDY variable is in the SDTM AE dataset
ADURN	Analysis Duration (N)	Num		Perm	Derive from ASTDT (or ASTDTM) and AENDT (or AENDTM).
ADURU	Analysis Duration Units	Char	(UNIT)	Cond	Conditional on whether ADURN is included
--DUR	Duration of XX	Char	ISO 8601 duration	Cond	Copied from XX.--DUR Because --DUR is a collected field and ADURN is derived, the values will often differ. Including XX.--DUR in addition to ADURN adds traceability. For SubClass ADVERSE EVENT, conditional on whether the AEDUR variable is in the SDTM AE dataset.
APERIOD	Period	Num		Perm	APERIOD is a record-level timing variable that represents the analysis period within the study associated with the record for analysis purposes. The value of APERIOD (if populated) must be one of the xx values found in the ADSL TRTxxP variables. See Section 2.9.6.3, Timing Variables for BDS Datasets, for more information on this variable.
APERIODC	Period (C)	Char		Perm	Text characterizing to which period the record belongs. One-to-one map to APERIOD.
APHASE	Phase	Char		Perm	APHASE is a categorization of timing within a study, for example a higher-level categorization of APERIOD or an analysis epoch. For example, APHASE could describe spans of time for SCREENING, ON PRODUCT, and FOLLOW-UP.

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Timing Variables