Should socioeconomic factors be considered as traditional risk factors for cardiovascular disease, as confounders, or as risk modifiers?

There is strong evidence that cardiovascular disease (CVD) and its traditional risk factors are associated with socioeconomic conditions. However, the latter's etiological role in the development of cardiovascular outcomes is not always well understood, and it is unclear whether they should be considered as traditional risk factors for CVD, as confounders, or as risk modifiers. After examining whether socioeconomic conditions meet the criteria for the three definitions, we argue that none of them fully captures the complexity of their contribution in shaping the epidemic of CVD across and within societies. We argue instead that socioeconomic factors are the "causes of the causes" of CVD. Implications for research and interventions to reduce CVD are discussed.