Introduction
ASSIGN is a cardiovascular risk score. The score was developed to prioritise the prevention of cardiovascular disease in those currently free of it by identifying those at highest risk. The score is ostensibly the ten-year percentage risk of developing cardiovascular disease (any manifestation of coronary heart disease or cerebrovascular disease including transient ischaemic attacks) in those disease-free at recruitment. So it is a number between 0 and 100. Note that although the score is "ostensibly" the risk percent over the next ten years this is based on historical data. There are reasons, including overall trends in disease rates, why current risks are probably lower. It is therefore more sensible to quote the ASSIGN score as the ASSIGN score, and its relevance as being in relation to the definition of high risk (ASSIGN 20) than to interpret it in terms of percentage risk as if this was a definite prediction. In any case, the overall aim is to lower the risk, not to carve it in stone. While the calibration of the score can be questioned on theoretical grounds, what matters is its discrimination. In other words, while a score of 10 may not actually be a risk of 10%, it does mean a higher risk than 5 and a lower risk than 15. It is this ranking of risk within a population which is the main purpose of the score, so identifying who is at highest risk.