• medical education
• medical journalism

Heading home from our summer holiday, the famous Edith Piaf song—imitated a thousand times, but never matched: ‘Non, je ne regrette rien’ came on the radio. This song spent 7 weeks at the top of the French singles charts in 1960, which would imply that the sentiment chimed with the broader population. I thought I’d listen through rather than change channels and found myself wondering about the meaning of the lyric, based flimsily on my schoolboy French. The idea that the singer regrets nothing is interesting, and one quite alien to me. I suspect that if I began to list here the things that I regret having done, I’d fill the journal, and be a blubbing wreck by the end of it. I’m not, however, going to expand on the theme of major regrets here. Instead, I want to write about minor regrets.

Perhaps one of the the most common minor medical regrets is ‘Why did I do that test?’ Of course, those of us in referral services are also familiar with the situation where we regret (perhaps a little passive aggressively) that somebody else did a test. You will probably be familiar with the situation. The test was done, and the outcome is not quite normal. And now, you need to figure out what to do with that information. Sadly, most of us cannot take the advice of a senior doctor I once worked with, who said ‘I would have not done the test in the first instance’—since time travel is probably impossible, or more accurately, only possible in one direction and at one speed.

We have a couple of papers which look at what you should do when you find something out that you, quite often, wish you didn’t actually know. Robert Hegarty and Anil Dhawan look at managing the child with the incidental finding of raised transaminases ( see page 228 ), and Adrienne Sullivan, Ruth Bland and Rosie Hague look at the child with the incidental finding of low IgA ( see page 231 ). When, some years ago, we were developing the Interpretations section I was struck that we have an odd attitude to the use of tests. When we decide we are going to prescribe a medicine we know quite a lot about that medicine. We will refer to one or more monographs on that medicine- although it might not feel like this when we access the information via an app and we try to come to a conclusion, weighing risk and benefit for this patient, about that medicine. One of the things I love about paediatrics is our comfort in returning again and again to those sources to just check the dose, in particular, for that size of patient, none of that silly macho memorising of doses for us; we know that our memories are leaky and are for much more interesting things like pattern recognition. So, if we’re this careful about medicine, then why aren’t we equally as careful about the tests we do? Perhaps because they are easier to do, but also perhaps because the negative impact of an unnecessary test, turning up a false positive which requires further invasive or distressing investigation, is more distant than, say, the effect of causing an adverse drug reaction.

There are lots of ways we can misuse tests. ‘I’ll just add this one too…’ can be one, particularly when we’re presented with a list of tick boxes and can therefore simply add a raft of further tests for almost no additional (personal) effort. More subtle is attempting to use a test to answer a question which it cannot answer. This is more obvious for some tests than others: the statement ‘I did a chest x-ray to diagnose the meningitis’ is as wrong headed as ‘I gave some furosemide to treat the meningitis’. However, the statement: ‘I ordered a chest x-ray to work out if the respiratory infection was viral or bacterial’ is probably just as wrong, just much harder to spot. The deliberately over-ambitious idea of Interpretations was to build a resource parallel to a drug formulary, but for tests. We’re a long way off but here we have two new excellent additions—Philip Robinson and Surjo Kiran De write about Procalcitonin ( see page 257 ), and Ben McNaughten, Anthony Thompson, Christine Macartney and Andrew Thompson look at how we should use a blood film ( see page 263 ).

Somebody wise once told me that you spend your first decade in medicine learning what to do, the second decade learning when to do it, and the rest of your life learning when not to do it. I think the fairest reading of Edith Piaf would be that she did not waste her opportunities for learning along the way, that to harbour regret at a deep level is to fail to accept that the experiences shape you and make you who you are. In any case, I hope that this edition helps you with whichever phase of learning about your practice you might be in. Once you’ve read and digested this edition, please do get in touch if you’ve got any thoughts about tests—or other items—we should be covering in your journal. And do have a listen to Edith Piaf, you get extra points if you play it loud enough to rattle the crockery.