WHAT IS HEALTH IMPACT ASSESSMENT?
Many sectors outside of health, such as transportation, housing, education, energy, and criminal justice, have substantial impacts on health. There is a need for methods to facilitate communication between decision makers in those sectors and public health professionals. One such method is health impact assessment (HIA), a systematic process that examines a proposed policy, plan, program, or project for potential positive and negative health impacts, and offers recommendations to promote favorable and mitigate adverse health outcomes (Box 44-1). Unlike other forms of evaluation designed to examine impacts after implementation, HIA seeks to inform proposed policies and projects before decisions are made. HIAs are designed to improve decisions from a health perspective, not to assess community health needs, nor to stop projects from moving forward.
BOX 44-1 Health Impact Assessment Definition
“HIA is a systematic process that uses an array of data sources and analytic methods and considers input from stakeholders to determine the potential effects of a proposed policy, plan, program, or project on the health of a population and the distribution of those effects within the population. HIA provides recommendations on monitoring and managing those effects.”1
HIA has its origins in environmental impact assessment (EIA), which uses a similar process to examine the potential environmental impacts of a proposed decision. The conduct of EIAs in the United States is based on the National Environmental Policy Act (NEPA) of 19694 that was designed “to promote efforts which will prevent or eliminate damage to the environment and biosphere and stimulate the health and welfare of man”(4, p. 4321) and to “assure for all Americans safe, healthful, productive and aesthetically and culturally pleasing surroundings”(4, p. 4331).8 While NEPA could be used to examine health impacts of projects and policies, in practice, health has received relatively little attention in most EIAs. For example, EIAs commonly estimate the change in air quality (an environmental impact) resulting from a proposed policy or project, but rarely estimate the associated change in respiratory disease rates (a health impact) that could be expected from that change in air quality.9 The use of EIAs, combined with a growing understanding of the influence of broader social, economic, and environmental factors on health outcomes,10 has led to the development of HIA as a separate tool. Published in 1999, the “Gothenburg Consensus Paper” is one of the first internationally recognized standards for HIA.11 Since then, there have been dozens of guidance documents and practice standards published in various countries throughout the world.1,12–15 Over 400 HIAs were conducted in the United States between 1999 and 2017.16
THE USE OF HIA FOR HEALTHY PUBLIC POLICY
There has been growing recognition in the field of public health that to improve population health and reduce health disparities, there is a need ...