In this example, a standard meal was administered to the subject.
The protocol prescribed that the meal be administered at a certain time relative to study drug administration. The planned timing of the meal is thus described using time point variables which include study drug administration as the reference time and a planned elapsed time. The planned elapsed time is the time between the start of the meal and the study drug administration. Since the meal is administered as part of a challenge test, it is treated as a procedure agent, and the data are in the AG domain. Lab samples are drawn at planned time points relative to the time of meal administration (not study drug administration). The meal is a standard meal whose nutrient content is prescribed in the protocol, so the nutrient content is described in the Trial Summary dataset.
The meal "dose" is collected using categorical responses for the portion of the standard meal consumed. These categories appear on the CRF using text such as "90-100%" meaning "between 90% and 100% of one standard meal." Representing this using the SDTM dosing variables presents some challenge. The AGDOSTXT variable can be used to represent ranges, and one solution would be to place "90-100" in AGDOSTXT and "%" in AGDOSU. However, in this context, the % symbol alone seemed ambiguous, since the base of the percent is not given. In laboratory tests expressed as percentages, the base of the percent is part of the definition of the laboratory test. However, there is no test code definition to rely on in an interventions domain, and since AGDOSTXT can hold any needed text, the amount of meal administered has been represented using text in AGDOSTXT that includes the % symbol and the base of the percent (the meal).
Row 1: A meal was administered 2 hours prior to study drug administration.
Row 2: A meal was administered 30 minutes after study drug administration. This visit happens approximately 26 weeks after the initiation of study treatment.