The role of health impact assessment in promoting population health and health equity.

Within the discipline of health promotion there has been long-standing understanding of the social determinants of health and life expectancy.1-3 There is also long-standing evidence of the unfair, unjust distribution of these resources within and among societies. It has proven difficult to translate this evidence of the need for the fairer distribution of socially-distributed resources into powerful action by the range of sectors through whose policies and programs/services much of this inequitable distribution is created.4 Health promotion has proven effective in contributing to significant improvements in the health of populations. It is, now, based on well-developed theory and a comprehensive body of evidence. However, health promotion in particular and the health sector in general have found it difficult to work with other sectors to influence public policy to create the social, economic, environmental and cultural conditions necessary for health equity. Health Impact Assessment (HIA) is outlined as an approach that offers the health sector a structured, transparent method and process to work with other sectors to predict the impact of policy proposals on the health of populations (and on the determinants of health), and to predict the distribution of these impacts in advance of adoption and implementation of the policy. Based on Australian experience of conducting HIAs, the paper outlines contributions that HIA can make to formulating and implementing of healthy public policy. It describes the steps in HIA and illustrates the use of these in practice.