ASSIGN for beginners
Who is this information for?
This information is for anyone who wants a simple introduction to the ASSIGN score and how it is used. More advanced information is also available on this website.
What is the ASSIGN score?
The ASSIGN score estimates a person's risk of developing cardiovascular disease. It is used to identify who is at high risk of having a heart attack or stroke. He or she can then be given special attention (see below).
What is cardiovascular disease?
Cardiovascular disease affects the heart or blood vessels. Among others it includes five serious conditions which share the same causes:
- angina
- heart attack (myocardial infarction)
- coronary heart disease
- stroke
- peripheral vascular disease (narrowing of the blood vessels, usually in the legs)
Coronary heart disease and stroke cause two out of every five deaths in Scotland and elsewhere. They also cause a great deal of illness in middle and old age.
Everyone is at risk of getting cardiovascular disease, but some people are more at risk than others.
How does the ASSIGN score work?
ASSIGN combines those risk factors which identify people who are at increased risk of cardiovascular disease, and are readily measured, to produce an overall score, the ASSIGN score. These risk factors are:
- age (being older)
- sex (being a man)
- where you live (higher risk in poor neighbourhoods)
- family history (relatives who have or had coronary disease or stroke)
- diabetes mellitus (whether the person being assessed, not the relatives, has sugar diabetes)
- tobacco smoking (cigarettes, pipe tobacco, or cigars)
- the blood pressure reading
- the blood total cholesterol reading – mainly ‘bad cholesterol’
- the blood HDL-cholesterol reading – ‘good cholesterol’
The ASSIGN score combines all the risk factors, and gives a score between 1 and 99. The higher the score, the higher the risk of cardiovascular disease.
A score of 20 or more is considered to be high, and is used to identify those people in greatest need of advice and treatment to reduce their risk.
Why are diet, exercise, obesity and alcohol consumption not included in the ASSIGN score?
ASSIGN combines readily measured factors known from many studies to lead to increased risk, each acting independently. There are many other factors which influence risk but are less readily measured, or, maybe, act through the ASSIGN factors, for example:
- diet (five portions a day of fruit and vegetables is not scored in ASSIGN, but is still important. Diet as a whole is difficult to measure but wise eating lowers risk).
- exercise (also important to practise, but difficult to measure simply, and not included).
- obesity (of increasing importance as a risk factor for developing cardiovascular disease and, even more so, diabetes mellitus. Is not independent of blood pressure and lipids. Losing weight is a good way to lower these, open to someone who is overweight or obese).
- alcohol (unlike tobacco smoking, causing increased cardiovascular risk at all levels of intake, alcohol intake is more complex to measure and in its effects. Excess chronic, or binge alcohol consumption relates more immediately to accidents, violence, and liver disease than to heart disease and is not included in most cardiovascular as against lifestyle scores.)
So because a risk factor is not scored in ASSIGN it does not mean that it is not important. The value of healthy exercise, diet and avoiding, or tackling overweight cannot be stressed too much.
How do I score cigarette smoking: what about quitters, pipe and cigar smokers?
Regular cigarette smokers
ASSIGN uses average number of cigarettes a day (cigarette dose equivalent) as the measure of the smoking dose. Average it out for occasional and weekend smokers. For never smokers insert zero, ie '0'.
Quitters
The added risk from smoking does not disappear immediately when somebody stops, but there is a question as to how rapidly this happens. Also many self-reported 'quitters' relapse fairly quickly. In a recent quitter, keep the previous intake as the dose for one year, then divide the previous number by two, after two years by three and so on. Five years after quitting the person can be treated as not smoking cigarettes. A cigarette smoker needs to stop completely as 'cutting back' usually means inhaling as much as before, so the dose in reality is unchanged. This applies also to cigarette smokers converting to pipe or cigar smoking. However, like other risk scores ASSIGN emphasises cigarettes.
Pipe and cigar smokers
The risk in pipe and cigar smokers is not so easy to measure, but rather than classifying them as non-smokers it is preferable to record the number of times per day on average that they smoke as equivalent to cigarettes. For mixed smokers record the number of smoking events, that is, for example, cigarettes plus other smoking and use the number as equivalent to cigarettes.
How do I score blood pressure: what about treatment?
Blood Pressure - Not On Treament
For ASSIGN scoring in subjects not on any treatment, record the systolic blood pressure as measured.
Blood Pressure - Already On Treament
This is less straightforward. The modern approach to blood pressure treatment and control should involve a full cardiovascular risk assessment. When blood pressure is lowered, the global cardiovascular risk does not come down as rapidly as for other risk factors. So risk is intermediate between the historical and current values shown by the ASSIGN score. Those on antihypertensive medication are already in medical care and should be considered for treatments additional to blood pressure lowering.
One way of scoring treated blood pressure is to add 20mmHg to the actual reading when entering systolic blood pressure into the risk estimation calculation. You can also look back at the pre-treatment reading and enter it to show whether the subject was at high risk before treatment began. This issue is being addressed in deriving a newer version of ASSIGN, ASSIGN2, so this is interim advice.
How do I score blood total cholesterol and HDL cholesterol: what about treatment?
Blood Cholesterol - Not On Treatment
For ASSIGN scoring in subjects not on any treatment, record the current total cholesterol reading as measured along with the HDL cholesterol reading as measured.
Blood Cholesterol - On Lipid Lowering Treatment
When blood cholesterol is lowered the cardiovascular risk comes down fairly rapidly so it is reasonable to use the current measured value for ASSIGN scoring both for total cholesterol and for HDL cholesterol. However, patients put on cholesterol lowering medication should have had a cardiovascular risk assessment when it was started. If medication changes the patient’s status from "high-risk" to "non high-risk" that is not a reason for stopping medication. Occasionally historical data on blood cholesterol and other risk factors might be used to look back and review whether medication was justified in the first place.
What does the ASSIGN number mean?
The ASSIGN score number is the estimated risk percent of getting cardiovascular disease over ten years. It is based on what happened to Scots men and women over the last 25 years. So ASSIGN 20 means a 20% risk, or one chance in five. The actual risk is almost certainly now less than that. What matters more is what somebody's score is in relation to other people's scores, and therefore how badly they need prevention now to lower their risk.
A high score (20 or more) does not mean you will definitely have a heart attack or stroke. It does mean that your chances are definitely worse than someone with a score below 20.
An ASSIGN score under 20 does not mean that you will never have a heart attack or stroke, only that you have a lower priority for preventive treatment than someone with a score of 20 and above.
The ASSIGN score is not used for people who have already been diagnosed with cardiovascular disease and are receiving treatment. If you have been diagnosed with one or more of the cardiovascular diseases in the list above, but are not receiving treatment, ask your GP about it.
What happens if I have a high ASSIGN score?
In Scotland you should be offered advice, support and treatment. That support may include being invited to join groups to help you with your diet, to stop smoking or to take exercise suitable for your age and health. Treatment would probably include medication to help reduce the chances of developing cardiovascular disease. These medicines could include:
- Low-dose aspirin to reduce the risk of blood clots (thrombosis)
- Statin tablets to reduce cholesterol levels
These medicines are known to reduce the risk of developing cardiovascular disease.
If your ASSIGN score is not as high as 20, you may still be given (or should find) advice about things you can do to improve your own health and lower your risk such as:
- Taking regular exercise
- Controlling your waistline and your weight
- Eating healthily
- Avoiding tobacco and excess alcohol
To find out more go to http://www.takelifeon.co.uk (external link)
What is the ASSIGN score based on?
The ASSIGN score is based on research carried out with 13,000 Scottish men and women in the 1980s and 1990s. These people had their risk factors measured and have now been followed for an average of 22 years.
Find out more about the SHHEC study (Scottish Heart Health Extended Cohort) used in the ASSIGN score.
Why is Scotland using the ASSIGN score when other cardiovascular scores are used elsewhere?
The most commonly used cardiovascular risk score worldwide is the Framingham score, developed in the USA. It is a good score that works well. There is also a European SCORE score. In Scotland much cardiovascular disease is associated with social deprivation. This is not fully explained by the risk factors included in the Framingham score. So the Framingham score does not target the socially deprived for treatment as much as they deserve compared with other social groups. The ASSIGN score is the first to include social deprivation and to deal with this social inequality. It also includes family history. For these reasons it is recommended for use in Scotland as against other scores such as Framingham scores, the JBS2 derivative, and QRISK (which was developed later and measures deprivation differently).
How does ASSIGN fit into preventive policies in Scotland and elsewhere?
ASSIGN was developed within, and should be implemented within, a programme for both primary and secondary prevention of CVD. It was launched with SIGN Guideline 97 in February 2007. The Scottish Government is committed to reducing health inequalities through Equally Well and its Keep Well CHD primary prevention programme of targeted health checks for people aged 40-64 living in the most socially deprived areas in Scotland. This is under evaluation. ASSIGN is being incorporated into GP database systems. Testing of ASSIGN is taking place within the Scottish Government programme of targeted high risk primary prevention, initially established in the Keep Well initiative for people aged 45-64 in the 15% most socially deprived areas in Scotland. Evaluation and estimation of the impact of ASSIGN in practices across Scotland will inform decisions regarding target populations for assessment (age and locality), and treatment thresholds, which could be progressive, and help thereby to optimise ASSIGN’s potential for reducing inequalities in CVD when nationally implemented.
ASSIGN could be used outside Scotland with adjustment for local indices of social deprivation, where available. Unlike conventional risk factors, these indices are not standardised internationally. Treatment thresholds would again need to be calibrated to the estimated workload. The ASSIGN website (www.assign-score.com) has generated heavy usage internationally, despite the need of users elsewhere to substitute for the SIMD score.
Can I measure my own ASSIGN score?
If you would like to measure your ASSIGN score on this website you can enter your risk factors. If you don’t know one or two of your risk factors you can use the average values for the Scottish population – but this will make the result less specific to you. If your score is near to or over 20, and you have not already spoken to your GP about cardiovascular disease, you should go to your GP for advice about further testing, self-help, other support or treatment.
Measuring your score is not a substitute for self-help or active treatment to lower risk. It is just a first step in helping you in prioritising prevention of cardiovascular disease. The ASSIGN score is best measured in a setting where the follow-through of advice and medication and follow-up are available from health professionals.
Where can I find out more?
If you are worried about your health or your risk of heart attack and stroke, you can call (in Scotland and Wales) NHS 24 on 08454 24 24 24 or speak to your GP.
Further information for professionals and other people who would like to know more is available on this website and in the listed publications.