As a radiologist I’m used to getting things wrong, but this one shook me up a bit

A couple of years ago, while driving home from my mother’s funeral, I did something really stupid. It was a long drive and I needed petrol so I pulled into a garage somewhere on the south coast and filled up, with petrol. Unfortunately I was driving my wife’s diesel car. Luckily I realised what I’d done while standing in the queue waiting to pay. I’ve never done that before and of course I’d like to think that I won’t do it again. I can readily explain to myself why it happened—the unfamiliar car, the unique circumstances, my head full of a lifetime of memories of my mother. Looking back, some sort of error seems almost inevitable—it’s a wonder that I didn’t crash the car as well.

At work I did something which now seems almost equally stupid. I failed to spot an unusual, but very important abnormality on the radiographs of an injured patient. I won’t give you details, not because I’m afraid of the consequences—luckily someone else spotted the abnormality even before I missed it and no harm resulted this time—but frankly because I’m too embarrassed. This is a condition about which I have taught registrars for a quarter of a century. If one of them subsequently failed to recognise it, I would have serious doubts about their competence. But I still missed it. This time no decent explanation comes readily to mind—I can’t blame a bereavement, I wasn’t sleep-deprived or under any particular pressure. Perhaps I was aware at some level that others were likely to be reviewing the same images and somehow allowed my attention to drift. I don’t know. As a radiologist I’m used to getting things wrong, but this one shook me up a bit.

The arch enemy of the radiologist is not so much ignorance as inattention. Not wilful inattention—few of us listen to the radio or carry out our online shopping while reporting—but the unconscious inattention and associated blindness which derives from the host of perceptual and cognitive biases to which all of us humans are subject. Not to mention the myriad distractions which can intrude on any busy clinical environment.

Some have likened radiological error to a surgical complication—an unavoidable risk inherent in the process. If we accept that a certain level of error is inevitable, then perhaps we should warn patients about it in advance? The question of seeking consent for exposing patients to medical radiation has been debated for years, but the risk of harm from misdiagnosis is very much greater. Occasional patients decline certain imaging tests because of radiation concerns. Would anybody decline a test because of a warning that it might be misinterpreted?

I have often been asked to give an “acceptable” rate of error by a radiologist and of course there is no answer to this. From the point of view of the individual patient, there is no acceptable error rate. Had the patient I mentioned above come to harm and subsequently found out about my error he or she would have had every right to complain. Perhaps a Serious Incident would have been declared, an investigation would have taken place, a “root cause analysis”. A set of actions would doubtless have been proposed, all designed to prevent anything similar happening again. Effective? I doubt it very much.  Yes, it does feel like a cop-out to blame my egregious error on human frailty, but I’m afraid that’s exactly what it was. That was the root cause. Could it happen again? Yes, I’m afraid it’s more than likely.

The important thing, we are told, is to learn from our errors, so what have I learnt from this episode? Not much more, surely, about a condition about which I have been teaching for 25 years. I suppose I have learnt that all my experience and all those years in practice don’t protect me from making really stupid mistakes. But maybe I knew that already.

Giles Maskell is a radiologist in Truro. He is past president of the Royal College of Radiologists.

Competing interests: None declared.