Accepting risk can be supported by a reasonable body of opinion.

Atrial fibrillation is a common cardiac arrythmia that predisposes a patient to stroke. That risk can be mitigated by prescription of anticoagulant.

I was recently discussing the use of heparin (an immediate, injectable anticoagulant) in the community with a consultant colleague. He suggested that when such a patient is discovered, he should be immediately anticoagulated, rather than wait until warfarin (an oral anticoagulant) takes its effect over several days. This is not common practice, because a patient discovered in primary care is likely to have been in atrial fibrillation for weeks or months, and a few days more at risk of stroke is unlikely to make much difference. “Ah”, my colleague said, “medicolegally, when you actually know your patient is in atrial fibrillation, you should act.”

Whenever anyone uses the word “medicolegally” or the phrase “for medicolegal reasons”, I know that they are not specialists in this field. The defence to a charge of negligence is whether a doctor’s actions would be supported by a reasonable body of opinion, not whether a doctor thought of every possible risk and acted accordingly.

This misunderstanding leads to overinvestigation and overtreatment. Such a distinction is crucial for primary care physicians to appreciate, where a lot of risk management takes place. Similarly, such superfluous treatment or investigation would not be a defence, if it were not supported by the famed reasonable body of opinion.