Thanks @abedtash_hamed. It's an interesting use case to consider a 'known side effect' that may have a lower real-world risk than what was previously observed in trials, because clinicians are now imposing their own risk minimization strategies.
I think you raise an important type of problem that I haven't really wrestled with before, namely how do you examine the short-term effects vs. long-term effects of a product. If there was some active comparator to use in the study, I could imagine specifying a fixed short-term window like 'to compare risk of CV events amongst patients with migraine who are new users of triptans vs. patients with migraine who are new users of indomethacin, during the period from 1d from exposure start to 180d from exposure start'. And then, to examine a longer-term effect, a question could be specified like: 'to compare risk of CV events amongst patients with migraine who are new users of triptans who remain continuously exposed for over 1 year vs. patients with migraine who are new users of indomethacin who remain continuously exposed for over 1 year, during the period from 1 year from exposure start until end of observation'. (note, in this second question, since we require the 1 year of continous exposure, we can't use that time as part of our time-at-risk).
What I can't quite work my head around is how to compare short-term exposure with long-term exposure. It's not clear how to reconcile the time-at-risk, since length of exposure is determining the comparator. Perhaps that's what we could sort out at the F2F, if this problem is selected in the voting.