A public health model of the social determinants of health.

As we move forward in the new century, epidemiologists and public health practitioners are faced with the challenge of reviewing the current direction of epidemiology and its links with public health. While the history of epidemiology has been a successful and productive one, there is a danger that modern epidemiology is becoming too narrow in its scope, concerned primarily with the analysis of risk factors in individuals, while ignoring sociological and ecological perspectives of health. We argue that a theoretical framework to guide the practice of epidemiology is needed which encompasses a role for social determinants of health while simultaneously also acknowledging the importance of behaviour and biology, and the inter-connectedness of all these factors. This paper presents a public health model of social determinants of health, which provides a framework for testing the causal pathways linking social determinant variables with health care system attributes, disease inducing behaviours and health outcomes. This approach provides an improved opportunity to identify and evaluate evidence-based public health interventions, and facilitates stronger links between modern epidemiology and public health practice.