In medical literature early adverse events are often counted for 30-day post procedure period. I was sure that the period's days are as follows: day of procedure, 1st day after, 2nd day after, ..., 30th day after. The question is whether the 30th day after the procedure is always included into the 30-day post procedure period. May some researchers exclude this day?


1 Answer 1


Surely, this is mostly a matter of definition.

An argument that the day of the procedure is "Day 1" and that one then considers "Day 1" to "Day 30" (=the 29th day after the day of the procedure) does not seem absurd - particularly if "Day 1" is (almost) a full day (i.e. particularly for a procedures that happen early in the day). If someone else argues that the part of the day of the procedure after the procedure to the 30th day after the procedure counts, I can also see a logic to it. This is mostly about whether you think the day of the procedure counts as a day ("rounding upwards to a full day") or not ("a started day is not really a day"). If someone else wants to use exact clock time to define the 30 day post-procedure period (e.g. time of end of procedure until 2,592,000 seconds later), that also makes sense.

I would generally expect that the definition should be clear in a study protocol/research report/publication.


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