Are there social determinants of health and disease?

The concept of a determinant is tied to the idea of a mechanism for action. Ideas from epidemiology, particularly the epidemiologic triad of agent, host, and environment, can help to make sense of factors that affect the absence of disease or that interfere with a mechanism that alters health. However, assembling convincing evidence for the existence of social determinants of health is a challenge, in part because of the difficulties of bridging the social and biological realms. While social contexts are measured using aggregates of individuals, disease and dysfunction occur at the individual level, leading to difficult problems of ecological inference. Although social factors have been shown to be associated with differences in mortality from specific causes, these factors account for only a small portion of the mortality from any individual cause. This suggests that the pathways through which social factors influence health are affected by their interactions with other factors.