Viedoc Randomization Webinar Q&A

  • Published by Viedoc System 2025-07-10
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This video is a recording of the Viedoc Randomization Webinar, part of the "Working Smarter series":

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Q: Where does the crossover happen, if a subject was randomized to acting, how would you assure this subject receives placebo in the second phase?

A: The treatment assignment happens at randomization. For the period 1 variable it is either active or placebo in the list for a given slot, and for the period 2 variable it is the other. These variables are then used at defined events where kit allocation would occur. For events that belongs to period 1 you use the period 1 variable, for those that are in period 2 you use the period 2 variable. By controlling which variable is used at which event and defining in the randomization list what is assigned in period 1 and then the other in period 2, different kit types would be allocated in the two periods.

Q: Is it possible to have a radio group with four options for the randomization and to map for the allocation two of the options of the radio group to one treatment?

A: That is possible by using two variables. One would be the group assignment which would be 4 different options. Two of these use the same treatment and for this a similar approach with more than one variable can be used. The second variable would then have 3 options and in the randomization list you make sure that all slots that are for, say group 1 and 2, use the same treatment in the second variable. Both variables are then set as blinded or unblinded output, whichever is applicable, in the RTSM configuration. And it is only the second variable (which corresponds to kit type/treatment) that is used as input for allocations.

Q: Can you share the randomization and the allocation list for the dose finding study?

A: All the examples, except for the basic example, can be found in our GitHub repository: https://github.com/viedoc/study-designs/tree/main/RTSM-examples. It also includes some instructions and the example design ODMs and lists.