'Don't you find it fascinating how fashions in medicine change? What is dreadful practice one year can become exemplary practice the next. Many years ago, when I was chairing the MRCGP Examination Board, I was contacted by a medical lawyer who needed to know how serious a crime it was to prescribe a beta-blocker to someone in heart failure. Now it's considered to be good practice. That's the glory of science, constantly checking and questioning, turning hypotheses upside down, refining the evidence. It's exactly how it should be, but it doesn't half make life confusing at times...'