Follow-up: The decimal-point error, and the habit that catches it

On the subject in the title: The decimal-point error, and the habit that catches it Working notes rather than a conclusion.

A follow-up question about decimal-point error that I did not know to ask the first time.

The earlier thread answered what I asked. What I should have asked is below, and I think it is the one that matters.

Do not shake. Swirl, or leave it. Vigorous agitation introduces air and shear, and neither helps a peptide go into solution any faster than patience does.

A single observation, in a thread that deserves better than single observations.

Noted, and thank you for writing it out rather than summarising it.

Write the reconstitution date and the concentration on the vial. Not on a note, on the vial. Every account here of a dosing error involving the wrong concentration involves a vial with nothing written on it.

A weak preference rather than a position.

Post #33 is right about the mechanism and I think understates the practical bit.

The decimal-point error: computing 5 mg / 2 mL as 0.25 mg/mL instead of 2.5 mg/mL is the most common arithmetic error in this subcategory. The habit that catches it: writing the units in every step of the calculation.

Two claims get bundled together under decimal-point error and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.

Almost every disagreement in threads like this one dissolves once you say which of the two you are making.

I would call the community position on decimal-point error likely rather than established, and I would be comfortable defending that hedge.

Everything in post #73 holds. The case it does not cover is the one I have.

Do not shake. Swirl, or leave it. Vigorous agitation introduces air and shear, and neither helps a peptide go into solution any faster than patience does.

I would hold that lightly until someone with a larger sample weighs in.

On decimal-point error, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the range is the interesting bit.

If you can post the two or three numbers you are working from, several people here will check the arithmetic rather than argue about the conclusion.