Public health interventions to reduce inequalities: what do we know works?

This commentary focuses on the notion of "what works" to reduce health inequalities. It begins by noting the need for and presence of a wide range of methodologies and approaches internationally. It then argues that it is useful to map out these contributions and those in the present Supplement against a set of principles (Macintyre, 2007) to guide the selection and implementation of public health interventions explicitly aiming to reduce health inequalities. The chosen principles derive largely from efforts to reduce steep and persistent Scottish health inequalities by social class. The commentary summarizes Macintyre's analysis of the main characteristics of public health interventions. It then notes that the present Supplement provides clear examples of population-health interventions and their health impacts that are inequality-reducing. The suggested approach and principles align with calls for the use of structural changes in the environment, early-life interventions, reductions in preventive-care barriers, and a harm-reduction philosophy. The commentary concludes that there remains much to learn and to do in order for public health intervention research to clearly demonstrate how to effectively reduce health inequalities in a lasting manner.