Cardiovascular disease (CVD) can be defined in varying ways but encompasses diseases affecting the heart and blood vessels. It includes these key conditions:

• coronary heart disease (CHD)
• stroke and transient ischaemic attack (TIA)
• peripheral arterial disease

The ASSIGN calculator has been developed to estimate the 10 year risk of coronary heart disease, stroke and TIA.

ASSIGN combines measurable risk factors which identify people who are at increased risk of CVD to produce an overall score, the ASSIGN score. These risk factors are:

• age (being older means higher risk)
• sex (being a man means higher risk)
• where the person lives (higher risk in deprived areas)
• family history (parents or siblings who have or had CHD or stroke under the age of 60)
• diabetes mellitus
• smoking
• systolic blood pressure.
• total cholesterol value – mainly ‘bad” LDL cholesterol
• HDL-cholesterol value – ‘good cholesterol’

The ASSIGN score combines all the risk factors by multiplication and gives a score between 0-100. The higher the score, the higher the risk of developing cardiovascular disease.

A score of 10 or more is considered high risk and is used to identify those people in greatest need of advice and treatment to reduce their risk.

More information on the formula used to calculate the ASSIGN score is available in the “What is ASSIGN and how was it developed” section (internal link) ** check name as currently is " What is ASSIGN"

The ASSIGN score number is the estimated risk percent of developing CVD over ten years in someone with no known CVD at time of assessment. So, ASSIGN 10 means a 10% risk, the key consideration is identifying those at highest risk for targeted intervention and risk reduction? – link to treatment and support see separate page.

A high score (10 or more) does not mean the individual will definitely have a myocardial infarction (MI), angina, or stroke. It does mean that their chances are higher than someone with a score below 10. Similarly, an ASSIGN score under 10 does not mean that they will never have an MI or stroke.

ASSIGN combines readily measured factors known to lead to increased risk. Other factors which influence risk, including blood pressure and cholesterol levels, but are less easily measured include:

• diet
• exercise
• obesity
• alcohol use

Despite not featuring within the scoring system, individuals should still be provided with appropriate lifestyle advice and support for these risk factors as action on them can lower their CVD risk.

Smoking in this score refers to tobacco use only.

Regular cigarette smokers

ASSIGN uses average number of cigarettes per day (cigarette dose equivalent) as the measure of the smoking dose. Average it out for occasional smokers. For never smokers insert '0'.

What about ex-smokers?

Whilst it is recognised that the cardiovascular risk from smoking reduces but continues for a number of years after quitting, this score is developed to calculate the risk for those who are current smokers and for non-smokers, hence there is no option to calculate the specific risk for ex-smokers. Previous data have suggested a halving in risk of coronary heart disease after 1 year of quitting, if the person has not yet quit for 12 months or more you may wish to calculate a score based on their previous daily amount. For information on the early and longer term benefits of quitting refer the person to the NHS inform page on Benefits of stopping smoking .

Pipe and cigar smokers

Record the number of times per day on average that the person smokes as equivalent to cigarettes. For mixed smokers record the number of smoking events.

Enter the values for blood pressure irrespective of whether on treatment or not. If the person has previously been commenced on antihypertensive treatment, that should have been as part of a full CVD risk assessment. If prior treatment lowers a person’s risk to non-high risk this is not a reason to stop treatment.

You could enter pre -treatment values if available to calculate a pre-treatment score for comparison purposes.

Enter the cholesterol values irrespective of whether the person is already prescribed lipid lowering treatment or not. Patients previously put on cholesterol lowering medication should have had a cardiovascular risk / benefit  assessment when treatment was started. If medication changes the patient’s status from "high risk" to " non-high risk" that is not a reason for stopping the medication in isolation. (To convert from mg/dL to mmol/L – divide the mg/dL value by 38.67)

If a persons non-HDL-C >=6.0  consider if this could be consistent with FH?

FH affects up to 1 in 250 people in Scotland, confers a high-risk of early-onset cardiovascular disease and is under-diagnosed. FH is autosomal dominant and can be confirmed via a sensitive genetic screen. Family screening for close relatives of an individual (with genetically confirmed FH) is offered throughout Scotland. 

Consider FH where ALL the following apply: 

• LDL-C >=5.0
• A non-inherited cause for hyperlipidaemia has been excluded e.g., alcohol excess, poorly controlled diabetes, uncontrolled hypothyroidism.
• Family history of hyperlipidaemia OR early-onset myocardial infarction (MI):
  • MI in 1^st degree relative (<60 years-old), or in 2^nd degree relative (<50 years-old)
    OR
  • LDL-C >=5.0 in 1^st/2^nd degree adult relative, or LDL-C >=4.0 in child/sibling <16 years-old

Where FH is suspected: 

• Do NOT use the ASSIGN score to guide primary prevention.
• Refer the patient to a lipid or cardiovascular risk clinic.

Ideally all risk factor information should be entered to obtain the most accurate ASSIGN score. If necessary, it is possible to calculate a provisional ASSIGN score using one or more average values to substitute for some missing values. These average values were obtained from previous Scottish Health Survey data see below.

After calculating a provisional ASSIGN score, you may wish to recalculate it substituting higher and lower values than the average to see how robust it is.

Mean values used for missing values – from the Scottish Health Survey 2011

Definition of extreme and out-of-range values

Extreme and consequent out-of-range values were defined from the survey data of the Scottish Heart Health Extended Cohort (SHHEC), involving over 18000 people. The usual range covers 95% of the study population leaving 2.5% at either end as unusually high or low for systolic blood pressure and cholesterol values and at the top end for cigarette consumption. They are kept the same for different age and sex groups.

Out-of-range values are those not occurring in the original study population.

For safety reasons, if an extreme value is entered then the value and the resultant score will be queried and flagged once calculated. See disclaimer page re extrapolation (internal link).

Where risk factor data are out-of-range or appear nonsensical (e.g., 'Yes' for 'Number of cigarettes') the risk factor value is rejected, and no score is calculated.? (Juliet – do not insert this text)  needed as will have validation warnings on calculator?

As ASSIGN was originally derived from the SHHEC cohort who were aged 30-74 at recruitment, the score is extrapolated if used for individuals beyond that range. Age is a dominant risk factor and risk will be high if the person is aged over 75 . (More recent population data used in the recalibration process included individuals aged 40-69). see disclaimer / limitations page (internal link).

SIMD (Scottish Index of Multiple Deprivation) is a deprivation score which is calculated for residential areas in Scotland. Each postcode can be matched with an SIMD score based on census and other social information from different agencies. You can test the effect of deprivation on risk, by entering SIMD values of 5, 20 and 55 which come from the least, middle and most deprived fifths of the population.

Scottish Index of Multiple Deprivation 2020  

The postcode I’ve entered has not been recognised.

There may be occasional postcodes that are not recognised or do not have a SIMD score allocated. In most cases the software will give you an estimated SIMD, or if it is unknown a median population value of 16.2 will be provided.

What if the person does not have a postcode?

For certain population groups e.g., those experiencing homelessness, travellers, and those in prison, it is possible to enter a substitute postcode. this substitute postcode is QQ1 1QQ which has an SIMD 2020 score of 44.6.

Cardiovascular disease and mortality rates are strongly associated with socioeconomic deprivation. The ASSIGN score was developed using Scottish population data and includes SIMD, a Scotland specific deprivation score as a risk predictor.

In SIGN 149 it was recognised that the previous threshold of 20% would need reviewed in the future to reflect the changing CVD risk within the Scottish population. ASSIGN was recalibrated in 2023/4 to acknowledge changing trends in population event rates and risk since its launch in 2006. The recalibration process used more recent Scottish population data. The updated recommended threshold is now 10% and is agreed for use with the ASSIGN (v2.0) risk calculator.

Therefore, the high-risk threshold for the score is now 10 rather than 20. An update of SIGN 149 is pending at time of writing.