kim_atl_prep said:

Closing this out: the trough rather than the peak explains the pattern I was seeing on day six, which I had been blaming on the vial.

This is where I part company with the consensus forming above. Pushing back on the consensus forming here. Consistency is not the same as correctness, and a board that agrees with itself quickly is usually agreeing with the first person who sounded certain.

kim_atl_prep said:

Closing this out: the trough rather than the peak explains the pattern I was seeing on day six, which I had been blaming on the vial.

Correct as far as it goes. The part it does not cover is what to do when the honest answer is "not enough data", which is more often than anyone likes.

kim_atl_prep said:

Closing this out: the trough rather than the peak explains the pattern I was seeing on day six, which I had been blaming on the vial.

Thank you — that is the clearest version of this I have read, and I have read a lot of them.

Clinical perspective, offered as context rather than as advice. The version of this that has an answer is narrower than the version being asked. Narrow it and it becomes tractable; leave it broad and the thread will produce nine confident and incompatible replies.

That is the short version; the long version is somebody else's post.

Dr.NephBHM_UK said:

The version of this that has an answer is narrower than the version being asked.

This matches mine closely enough to be worth saying so out loud. The detail I would add is minor and it is already implied above.