Background Statins are cholesterol lowering drugs that are prescribed to lower the risk of cardio-vascular diseases (CVD). The use of statins has increased markedly and it is now one of the most prescribed drugs in the world. 600,000 people in Denmark are taking statins on a daily basis, 40 % of these are taking the medication without having any other risk factors for CVD than elevated blood-cholesterol i.e. they are in primary prevention.