Non-inferiority and choice of scale (absolute vs relative)

I am trying to understand more about non-inferiority trials and one thing that I am struggling with (for binary outcomes) is when it might be more appropriate to choose either an absolute (i.e. risk difference) vs relative (RR/OR) for establishing the non-inferiority margin. Are there any good reasons for choosing one over the other? Intuitively (for me) an absolute difference feels easier to work with…

An absolute scale is harder to work with because every patient will have a different absolute risk reduction (ARR is a function of baseline risk).

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