Risk Factors
Risk-Factor Means to substitute for missing values
It is desirable to obtain values of all requested risk factors before calculating the ASSIGN score. However, it is possible to calculate a Provisional ASSIGN score using one or more mean values to substitute for missing values. These were obtained from the Scottish Health Survey 2011 so they are more recent than those obtained from the SHHEC study. Through an oversight these values, although listed here, were not incorporated into ASSIGN Version 1.5. They are now incorporated into the algorithm for ASSIGN Version 1.5.1. Note that this has no effect on calculation of the ASSIGN risk score where risk factor values are all known, and only minor changes to 'provisional scores'. The values are:
| Age (years) | Cigarettes per day | Systolic Blood Pressure | Total Cholesterol | HDL Cholesterol | ||||
| Male | Female | Male | Female | Male | Female | Male | Female | |
| 25-34 | 12 | 11 | 125 | 114 | 4.9 | 4.8 | 1.3 | 1.5 |
| 35-44 | 14 | 13 | 127 | 121 | 5.5 | 5.2 | 1.3 | 1.5 |
| 45-54 | 17 | 16 | 130 | 125 | 5.6 | 5.7 | 1.3 | 1.6 |
| 55-64 | 19 | 15 | 135 | 132 | 5.5 | 6.0 | 1.4 | 1.6 |
| 65-74 | 17 | 14 | 136 | 139 | 5.2 | 5.7 | 1.4 | 1.6 |
Smoking status should be known to calculate the ASSIGN score and should be requested if not available. If other factors are available, but not smoking, calculate a tentative score for a non-smoker and then for a smoker smoking an average number of cigarettes. Record both values to show the potential risk status, and then verify true status when you can.
In addition to the information here see advice concerning ex-smokers, pipe and cigar smokers under Scoring smoking concerning ex-smokers and pipe and cigar smokers in FAQs
After calculating a Provisional ASSIGN score the clinician may like to recalculate it substituting higher and lower values than the mean to see how robust it is, and how desirable to go back and obtain a real risk factor value to give a definitive score.
Risk-Factor Limits for ASSIGN. Definition of extreme and out-of-range values
For safety reasons it is undesirable to calculate an ASSIGN score in clinical practice using values which are so extreme as to be almost never encountered. The value may be erroneous; if not entered in error the measurement would need to be repeated, and if still true would be the subject of additional specific measures, not just incorporation into a risk score. Such values are queried when entered, as is the resulting score, which is calculated but flagged as questionable. Where risk factor data are out-of-range or nonsensical (eg 'Yes' for 'Number of cigarettes') the risk factor value is rejected and no score is calculated. These rules are slightly relaxed for the Research (ASSIGN for visitors) version of the score data entry entry format, allowing the user to conduct 'What if?' analysis. Extreme and out-of-range values were defined from the survey data of the Scottish Heart Health Extended Cohort (SHHEC), involving over 18000 people. For simplicity (unlike risk-factor means) the same values are used for extremes and ranges for different age and sex groups. Out-of-range values are those not occurring in this study. Extreme values are those occurring in less than 1% of participants.
The exception to the above rule is that ages beyond those of the original SHHEC cohort of 30-74 years are flagged because scoring involves extrapolation and the very young and very elderly are excluded although encountered in clinical practice. (See below)
| Risk Factor | Lower Bounds (inclusive) | Upper Bounds (inclusive) | ||
| Extreme Range | Usual Range | Extreme Range | ||
| Age (Years) | 25 | 30 | 74 | 90 |
| Cigarettes per day for smokers () | 0 | 0 | 40 | 100 |
| Systolic Blood Pressure (mmHg) | 80 | 100 | 200 | 250 |
| Total Cholesterol (mmol/l) | 2 | 3.5 | 9 | 12.5 |
| HDL Cholesterol (mmol/l) | 0.3 | 0.6 | 2.3 | 3.5 |
More Information
Age: this is a major component of risk, so a value must be entered, accurate or estimated. An ASSIGN score of 20 or more is unusual below age 50 but very common at 65 or over where it applies to most people. Some scoring systems limit the age range to whom they are applied, or freeze the age so that there is a maximum age which can be entered. ASSIGN was derived from the SHHEC cohort who were aged 30-74 at recruitment so the score is extrapolated if used beyond that range.
Sex: whether the subject is male or female is a major determinant of subsequent cardiovascular risk, so it must be allocated correctly.
Diabetes mellitus: this adds considerably to risk and many management plans treat all diabetics with secondary prevention. This item is there for use where an ASSIGN score is being allocated to a known diabetic, otherwise leave it alone.
Rheumatoid arthritis: sufferers have an enhanced risk of cardiovascular disease which may be mitigated by modern treatment. They should be offered cardiovascular risk assessment as part of the United Kingdom QOF (Quality and Outcomes Framework) for 2013-2014 which includes rheumatoid arthritis as a new clinical area.
Smoking: in addition to the information here see Smoking in FAQ section concerning ex-smokers and pipe and cigar smokers.
Systolic Blood Pressure: in addition to the information here see Blood Pressure in FAQ section concerning treated hypertension.
Total cholesterol: in addition to the information here see Cholesterol in FAQ section.