To the Editor: There would be few medical students who have not had drummed into them the tautological aphorism, “Common things occur commonly!” And few practising clinicians who have not come across or read about a serious adverse event arising from the actions of a colleague or nurse who thought, “It was only X, which is so common at this time of the year/around these parts/among these people. I didn’t think it was anything serious.” The patient might have been a child with meningitis sent home with a diagnosis of a winter upper respiratory tract infection or a very anxious young woman with an intracranial haemorrhage discharged with a diagnosis of tension headache.

Guided by this aphorism, we doctors will almost always make the correct diagnosis, and nurses an accurate assessment of a patient’s complaints, and we will glow with professional satisfaction. But how does this boost to our professional confidence measure up against what should be our paramount concern — the safety of each patient in our care?

When assessing junior colleagues, we must, above all else, be seeking reassurance that patients will be safe in their hands. We do not want to hear a junior doctor brushing aside a commonly occurring symptom or clinical sign as of little importance merely because it is common. But we do want to know that he or she has considered, “What is the most serious condition that this could be?”, followed by relevant enquiries into the patient’s history, appropriate clinical examination and warranted laboratory or other investigations. Knowing that the doctor has checked that there is no suggestion of a serious illness, we can be reasonably assured that the patient will be safe.

An excellent candidate would make the correct diagnosis sooner and perhaps with less pain, discomfort and inconvenience for the patient, and at less cost to the health care system, than a less able colleague. But the patient will be safe with either doctor, as a dangerous, perhaps life-threatening, illness has been excluded. All that remains is for the correct diagnosis to be made and appropriate treatment administered — a burden for the patient perhaps, but not a disaster.

I suggest that readers of the Journal, in their role as teachers, advise their students to abandon that inane and dangerous “commonness” tautology, and replace it with: “Exclude the worst possibility and then assist Nature in its healing processes”.