Sir, Dr Korada's letter, Antibiotic prophylaxis: a myth? (BDJ 2006; 200: 5) highlights one of the most common problems with evidence-based practice – everyone can quote an exception.

It is imperative to appreciate that there will be patients who do not get infective endocarditis in spite of having accepted risk factors and also those who do in spite of having no risk factors.

I think it is harder for us as surgeons to accept evidence-based practice as we learn much of our craft through our own experience; over the years we develop our own ways of doing what works for us and our patients. However we do have to accept that working parties are unlikely to alter their guidelines based on a few isolated exceptions and if we choose to practise outside of the guidelines we have to be prepared to defend ourselves in court; quoting one previous case is unlikely to be a good defence.