[Model for estimation of cardiovascular risk in Norway]

Abstract

Background: Guidelines for prevention of cardiovascular disease (CVD) include calculation of total risk. A new risk model based on updated Norwegian data is needed, as the European SCORE function overestimates the risk of fatal CVD in Norway. NORRISK for 10-year CVD mortality is presented. It includes gender, age and smoking and levels of systolic blood pressure and serumtotal cholesterol.

Material and methods: NORRISK is based on national age- and sex specific mortality rates from Statistics Norway (1999-2003), mean levels of risk factors from Norwegian Health Surveys (2000-03) and relative risks from mortality follow-up of Norwegian Cardiovascular Screenings (1985-2002). The model is adjusted to the mortality level in the period 1999-2003 and is compared with the SCORE model.

Results: 10-year risk estimates calculated from NORRISK fall between SCORE high- and low-risk estimates and increase strongly with age. Very few persons below 50 years of age have a 10-year risk above 5% (European limit for high risk). More than half of men aged 60 years have estimated risks above this limit, while only 7% of 60-year-old women exceed the limit. Even if the risk limit is reduced to 1% for younger age groups, very few women below 50 years of age have risks above the limit.

Interpretation: NORRISK is more adapted to the current situation in Norway than the SCORE model and may be a useful and relevant tool in Norwegian clinical practice.