Let's play a little imagination game.

You are  on a cross-Channel ferry, on your way to France, traversing the most densely-packed waterway in the world, surrounded by millions of tons of floating metal people carriers all just waiting to bang into each other. 

 Unless you're the particularly nervous type, you feel safe, because there are very strict rules and regulations surrounding marine travel.Your captain and his officers are well-trained, their competence regularly assessed; and in the event of an emergency, there will be enough members of crew to ensure your safety. Sail on, hit the duty-free, look forward to a good meal when you land.

But what if you learned that your captain and his officers had, before today, never been in charge of anything bigger than a Lake District ferry, but had been instructed in a classroom about the principles of crossing the Dover straits? And in fact, there was only the captain, no officers at all on board, the rest of the crew being people who had wandered by the docks and given jobs on the grounds that they 'liked boats'? Still enjoying that view of the White Cliffs as they shrink behind you?

Since 1995,  British nurse training has not been based in hospitals - 'universities' (some of these establishments having only being granted that title a few years before) took on the job. In an 'androgogical paradigm shift' (or, to put it another way, a fit of complete madness), student nurses would spend half of their time learning about the shouty hurty things in beds we used to call patients - now, 'service users' or 'customers' - from textbooks.

It's taken a while, but eventually, the people who direct policy (and who tend not to know one end of a bedpan from the other) realised the problem, and as I write, they are still sticking plasters over the compound fractures in nurse education as they try to rectify matters. (If this sounds unfair: the professor of surgery regularly operates on patients. Ask your local professor of nursing how much patient contact they have.)

Quite a few nurses underwent this 'training', and are in charge of wards now. The vast majority came to see, once faced with the realities of ward management, the shortcomings of their preparation, and worked hard to make up for it. But it is still a problem.

However, cutting  to the chase at last: 'safe staffing levels'. With the honourable exception of Private Eye's correspondent 'MD', the media throw about the term 'nursing ratios' in relation to staffing levels without thought or care. 

On a ward of 24 patients, if there are two registered nurses and four healthcare assistants (HCAs) on duty, the nurse:patient ratio is 1:12; the staffing ratio is 1:4. This last figure sounds pretty good; but it depends on the quality of those untrained staff. Once upon a time, the training and updating of such staff was ward and classroom based;,and it wasn't too hard to spot the ones who might not be up to the job (and those who should be encouraged to go on to nurse training). Now, they can do a lot of their 'continuing professional development' online, ticking boxes on a multiple choice questionnaire, often with the help of colleagues who actually made the effort to read the 'training materials'.

All talk of 'safe staffing levels' is meaningless, if only numbers are considered. In my experience, three experienced registered nurses, running a shift on a ward with 20 patients, tend to make a better job of it than one RN and four HCAs, if the latter aren't top-notch. But quality doesn't matter, does it?

Think of a number. Any number. And you'll find it means nothing.

(Note: the author qualified as  a registered nurse in January 1984, and was an HCA before training)