Primary prevention of cardiovascular disease: new guidelines, technologies and therapies

To the Editor: In describing an approach to primary prevention of cardiovascular disease (CVD) based on 5-year absolute risk, Nelson and Doust acknowledge that this strategy is unlikely to be tested with a randomised controlled trial.1 Yet there are many examples in medicine where guidelines based on good intentions were subsequently shown to be inappropriate when tested in randomised controlled trials. Caution is required in adopting a formulaic approach to primary prevention of CVD, and there is a need for a greater appreciation of the arbitrary way in which CVD risk is categorised and the lack of precision in its estimation.