Timeframes (referred to as study reference periods), fixed points in time, and other milestones, may be defined in the context of a study as references to which the timing of other collected observations are related. The following will be collected using TIG Collection or CDASH Model Timing variables when references for the timing of other observations are defined:
- Start and end dates, and times as applicable, for study reference periods.
- Dates, and times as applicable, for fixed points in time and/or milestones used as references.
The date, and time as applicable, of an observation related to a reference will be collected whenever possible. Only in cases where it is not possible to collect the date of a related observation (e.g., the date is not available), will a relative timing for the observation be collected. Relative timing will be collected using TIG Collection Variables:
- --PRIOR to indicate the timing of the observation was prior to the start date of a reference period or the date of a fixed point in time or milestone; or
- --ONGO to indicate the timing of the observation was ongoing relative to the end date of a reference period or the date of a fixed point in time or milestone.
see Section 8.1.1, General CDASH Assumptions for Interventions Domains, and Section 8.2.1, General CDASH Assumptions for Events Domains.
The following steps should be taken to ensure observations of interest that occur over time can be related to the study reference period or to a fixed point in time/milestone in a meaningful way.