NORRISK2 and SCORE2
The Norwegian guidelines for prevention of cardiovascular diseases recommend using the NORRISK2 risk model (2, 6) to estimate the risk of an acute myocardial infarction or cerebrovascular stroke within the next ten years. This model is based on follow-up of large Norwegian cohorts and is thus adapted to Norwegian conditions. The European guidelines include the SCORE2 (2) risk model for persons under 70 years and the equivalent SCORE2-OP (8) model for those who are older. The NORRISK2 and SCORE2 models have both been developed according to the same principles and use life expectancy models that take competing risks of death into account (5, 7, 8). All the models include age, total serum cholesterol, HDL cholesterol, daily smoking (yes/no) and systolic blood pressure. However, the models differ in some respects. For example, NORRISK2 dichotomises HDL cholesterol (heightened risk at HDL < 1.0 mmol/L in men and < 1.3 mmol/L in women), whereas HDL is included as a continuous variable in SCORE2. In addition, NORRISK2 includes use of antihypertensive drugs (yes/no) and information on early myocardial infarctions in the immediate family.
We have compared the estimated risk from the SCORE2 models for areas with a very high risk with what is obtained from NORRISK2 with the same risk factors. The figures are drawn from Figure 2 in the article that describes NORRISK2 (5) and Figure 3 in the European guidelines (3). Table 2 gives some examples (3, 5). As shown, men in the age group 50–54 years who are non-smokers and have a total cholesterol level of 6 mmol/L, blood pressure of 150 mmHg and an HDL cholesterol level of 1.4 mmol/L have an estimated ten-year risk of 5 % according to NORRISK2 and 11 % according to SCORE2 in areas with a very high risk. Here, we have entered 'no' for antihypertensive treatment and 'no' for family history in NORRISK2, which reflects an optimal profile for these factors. It is not possible to make similar entries in SCORE2.
Table 2
Example of ten-year risk of a cardiovascular event estimated by NORRISK2 and SCORE2 for populations with a very high risk of cardiovascular disease, given that systolic blood pressure = 150 mmHg, total cholesterol = 6.0 mmol/L and HDL cholesterol = 1.4 mmol/L (non-HDL = 4.6 mmol/L)1 (3, 5)
| | Non-smoker | | Smoker |
|---|
| Sex/age | NORRISK2 (%) | SCORE2 (%) | | NORRISK2 (%) | SCORE2 (%) |
|---|
| Women | | | | | |
| 50–54 | 2 | 9 | | 5 | 18 |
| 60–64 | 5 | 17 | | 10 | 29 |
| 70–74 | 11 | 34 | | 17 | 44 |
| Men | | | | | |
| 50–54 | 5 | 11 | | 10 | 19 |
| 60–64 | 10 | 19 | | 16 | 28 |
| 70–74 | 18 | 33 | | 22 | 41 |
The NORRISK2 model is thus likely to significantly underestimate the ten-year risk of cardiovascular disease among refugees from Ukraine
The NORRISK2 model is thus likely to significantly underestimate the ten-year risk of cardiovascular disease among refugees from Ukraine. These patients should therefore be treated at a lower level.
The Norwegian guidelines already note that for a given level of blood pressure, cholesterol and smoking habits, people with a background from South Asia will be at a 1.5 times higher risk than the general Norwegian population. Since we are now expecting a considerable number of people from Ukraine to arrive in Norway, it is important to be aware that we will be facing a group that is at a significantly heightened risk. They may also be suffering from high levels of psychosocial stress, which may further aggravate the risk.