In your case, ARM and ARMCD variables should represent subject randomization info (Planned Treatment Arm) like ARMCD=“A300”, while ACTARM and ACTARMCD variables will represent subject treatment (Actual Treatment Arm) and have a missing value according to FDA Guidance like ACTARMCD=“”.
Please note that ARM variables store Treatment information rather than Randomization ID. For example, it should be something like “Drug A, 300 mg” (treatment info) rather than “162537” (randomization number).
I have a question about SDTM DM ARMCD and ARM data about below case:
The subject was mistakenly randomized but not treated study drug. And, the subject’s data has been changed to “No(screening failure)” from “Yes(screening pass)” on screening pass yes/no page.
Then, according to the 2020 Nov FDA TCG, if randomized subject and not treated study drug, is ARM and ARMCD assigned corresponding to the random id? Otherwise, should the ARM, ARMCD be assigned as Screen Failure, SCRNFAIL?