Clinical perspective, offered as context rather than as advice. Take it one variable at a time. Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent argument can untangle them after the fact.

TrialTracker_MD said:

Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent…

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. The objection nobody has made: this only works if the measurement is doing what we assume it is doing, and that assumption has not been tested here.

TrialTracker_MD said:

Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent…

That is correct as far as it goes, and here is where it stops going. Yes, and the corollary is less popular: if the reasoning holds, it also holds where it produces an answer we do not like.

TrialTracker_MD said:

Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent…

Thank you for spelling out the reasoning rather than just the conclusion.

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