Can individuals with a significant risk for cardiovascular disease be adequately identified by combination of several risk factors? Modelling study based on the Norwegian HUNT 2 population

RATIONALE, AIMS AND OBJECTIVES: Clinicians are generally advised to consider several risk factors when evaluating patients' cardiovascular disease (CVD) risk. Our aim was to study whether combined assessment of five traditional risk factors might help doctors demarcate a relatively distinct and manageable group of high-risk individuals. We selected five modifiable risk factors and estimated the proportion of a well-defined population with ‘unfavourable’ levels of at least two of them, as defined by four internationally renowned guidelines. The impact of including so-called ‘prehypertension’ among the risk factors was specifically addressed, and the results are discussed in a wider perspective. MATERIAL AND METHODS: Guideline implementation was modelled on data from a cross-sectional Norwegian population study comprising 62 104 adults aged 20–79 years (The Nord-Tröndelag Health Study 1995–7). Total, age- and gender-specific point prevalences of individuals with zero, one, two, three or more factors, in addition to established disease, were calculated. RESULTS: One single CVD risk factor was exhibited by 12.4% of the population; two factors by 21.5%; and three or more by 49.7%. Established CVD or diabetes mellitus was reported by 12.5%. In total, 83.7% of the population exhibited a risk or disease profile with at least two factors, if prehypertension was included. CONCLUSIONS: If guideline recommendations are literally applied, as many as 84% of adults in Norway could exhibit two or more CVD or risk factors and thus be considered in need of individual, clinical attention. This challenges the widely held presumption that ‘the net will close’ around a manageable group of individuals-at-risk if several risk factors are jointly considered. As the finding of this study arises in one of the world's most long- and healthy-living populations, it raises several practical as well as ethical questions.