Background: The combined effect of social status and risk factors on the absolute risk of cardiovascular disease has been insufficiently investigated, but results provide guidance on who could benefit most through prevention.
Methods: We followed 77,918 cardiovascular disease-free individuals aged 35-74 years at baseline, from 38 cohorts covering Nordic and Baltic countries, the UK and Central Europe, for a median of 12 years. Using Fine-Gray models in a competing-risks framework we estimated the effect of the interaction of education with smoking, blood pressure and body weight on the cumulative risk of incident acute coronary heart disease and stroke.
Results: Compared with more educated smokers, the less educated had an added increase in absolute risk of cardiovascular disease of 3.1% (95% confidence interval + 0.1%, +6.2%) in men and of 1.5% (-1.9%, +5.0%) in women, consistent across smoking categories. Conversely, the interaction was negative for overweight: -2.6% (95% CI: -5.6%, +0.3%) and obese: -3.6% (-7.6%, +0.4%) men, suggesting that the more educated would benefit more from the same reduction in body weight. A weaker interaction was observed for body weight in women, and for blood pressure in both genders. Less educated men and women with a cluster of two or more risk factors had an added cardiovascular disease risk of 3.6% (+0.1%, +7.0%) and of 2.6% (-0.5%, +5.6%), respectively, compared with their more educated counterparts.
Conclusions: Socially disadvantaged subjects have more to gain from lifestyle and blood pressure modification, hopefully reducing both their risk and also social inequality in disease.
- Social inequalities
- Cardiovascular disease risk
- Differential vulnerability
- Additive interaction
- Competing risks