Letters

Hand hygiene before anything else is the single highest-yield step in every published account of technique in any setting, and it is the step most often skipped because it is the least visible.

Sharps disposal is not an afterthought and the article treats it as one. A rigid container, obtained before it is needed rather than after, is the whole of the advice, and it belongs at the start of the sequence rather than at the end.

The unit confusion in this area is a design problem rather than an education problem. A syringe graduated for one purpose, used to measure a volume of something else, will produce errors at a rate determined by the markings and not by the diligence of the person reading them.

You recommend writing the concentration on the vial. I would add: write it on the box as well. My vial label came off in the fridge and I lost the only record of what diluent volume I had used.

A methodological plea. Publish the purchase date, the arrival date and the determination date for every blind result. Without all three, a poor figure cannot be attributed between manufacture, freight and storage, and every party will attribute it wherever suits them.

The distinction that matters is not blind against named but who chose the sample. A blind submission of a vial the seller selected is not blind in any sense that protects the reader, and the word is doing all the work in that sentence.

The trials are conducted with pharmaceutical-grade material under supervision. Whatever they establish, they establish about that material in that setting, and the extension of their findings to a research-supply context is an assumption rather than a result.

I have read four of these studies and none reported what participants were told about the possibility of regain. Expectation is a variable in any outcome that includes behaviour, and it is entirely unmeasured across the set.