Calculation Format
Meaning of the ASSIGN score
The ASSIGN score is the estimated risk of people who are free of cardiovascular disease at that time, of the same age and sex and risk factor values to those entered into the score, developing coronary heart disease, a transient ischaemic attack or stroke, or death from cardiovascular disease over the next ten years. It is based on the historical experience of a large number of Scottish men and women in the Scottish Heart Health Extended Cohort (see below) followed for ten years. Thus a 20% risk (the conventional cut-point for intervention) means that one fifth will develop cardiovascular disease and 50% means one in two. Note that this is not the relative risk (or risk multiple) but the actual or 'absolute' risk. However, it is an estimate and not a guarantee. A high score is compatible with going for ten years with freedom from cardiovascular disease. A low score is compatible with developing premature cardiovascular disease - but the probabilities are different. The score ranks people by their risk of developing future cardiovascular disease and therefore prioritizes them for preventive action based on their scores.
The ASSIGN score is designed to emulate, but replace its predecessor, the Framingham score, by incorporating social deprivation and family history. The Framingham score, based on a historical American population, gives higher values on the whole in its cardiovascular version (see references) than does the ASSIGN score, but there is a very high correlation between them. (However, there are several different Framingham scores and a Framingham derived score used by JBS2 gives lower values). ASSIGN usually scores lower than the Framingham cardiovascular score without social deprivation or a positive family history, but with them it scores higher, particularly in older women. The ASSIGN score is considered by the SIGN guideline development group on cardiovascular disease and by the Scottish Government Health Department to be the most appropriate cardiovascular risk score for current use in the Scottish population, because it includes social deprivation, family history and numbers of cigarettes smoked.
For further discussion see Cardiovascular Risk and Risk Scores, ASSIGN, Framingham, QRISK and others: how to choose.
Framingham
The Framingham score is the standard and original coronary or cardiovascular risk score. It was the Framingham study that first introduced the concept of risk factors and which defined the 'classic risk factors' used in its score. The Framingham score is as good (and as bad) as similar scores in discriminating future event-victims from non-victims, but it may overpredict (or rarely underpredict) event rates in different population. This problem can be resolved by altering the calibration or the cutpoints. The standard Framingham scores did not include family history (some versions now do) or any measure of social status. The ASSIGN score was developed because the Framingham score was not considered 'wrong' but unfair for those reasons which are corrected in the ASSIGN score. The latter can be used in heterogeneous modern populations of mixed social status and ethnicity and compensates for the consequent problems in estimating risk status.
Because the Framingham score was the standard, the 1991 cardiovascular version of it was made available on the ASSIGN cardiovascular score website for illustrative purposes in 2006, when it was first launched. There are now several different Framingham scores available on the internet, with varying answers, and the facility has been withdrawn from this website to avoid confusion.
ASSIGN gives similar answers to the 1991 Framingham cardiovascular score of Anderson et al – mainly marginally lower, but higher in the socially deprived and in older women.
A Framingham score is available from the USA sponsored by the NIH/NHLBI, which funds the Framingham study. (Lipid units are in mg/dl. To convert from mmol/l to mg/dl, multiply by 38.5). http://cvdrisk.nhlbi.nih.gov/ (tested 2016-02-10)
There are other Framingham sources, including some in the UK.