Health disparities between different populations in the United States are driven by inequities in determinants of health: environmental, social, and economic factors such as housing, income, employment, and education that shape people’s health and well-being. To improve public health and promote health equity—the guiding principle that disparities in health outcomes caused by factors such as race, income, or geography should be addressed and prevented, providing opportunities for all people to be as healthy as possible—policymakers must identify, implement, and then evaluate interventions across diverse sectors.
Health impact assessments (HIAs) can aid those efforts. They use a standardized six-step process to investigate how decisions—such as whether to develop a transit system, build a park, or construct a natural gas plant—could affect health, to encourage the consideration of public health and health equity in decision-making, and to develop recommendations to promote better health outcomes and greater equity. Although studies have documented the short-term value of HIAs, to date relatively little has been known about their effects on determinants of health and health equity over the longer term.1 New research commissioned by the Health Impact Project, a collaboration of the Robert Wood Johnson Foundation and The Pew Charitable Trusts, and conducted by Harder and Co. Community Research, has reviewed dozens of HIAs from across the country (see Figure 1) to better understand and offer strategies to improve HIAs’ longer-term impacts. The HIAs included in the study examined decisions that had the potential to affect one of three health determinants—employment; safe, affordable, healthy housing; and access to healthy food.2
Key takeaways include:
- Decision-makers adopted recommendations from at least half of the 29 HIAs for which data on such implementation was available:
- At least one recommendation was adopted for 92% of HIAs that focused on housing, 64% of HIAs that focused on food, and 50% that focused on employment.
- All recommendations were adopted for 8% of housing HIAs, 27% of food HIAs, and 17% of employment HIAs.
- Factors that influence the likelihood of implementation include feasibility, political will, timing and alignment with current plans, and clearly articulated recommendations.3
- HIAs can boost community members’ capacity to participate in decision-making. For example, in response to questionnaires about an HIA conducted in 2012 in Columbia, Missouri:
- 73.7% of community residents said the HIA strengthened relationships between community residents and local decision-makers.
- 78.9% said the HIA empowered residents to get involved in a policy issue.
- 73.7% said the HIA showed people how to participate in efforts that would improve community conditions.
- 63% and 61% said that the HIA encouraged people to get involved in volunteer or civic engagement activities, respectively.
- HIAs may promote systemic changes that could advance health equity. However, this impact was not demonstrated for all studied HIAs, so further examination is needed to measure its extent. In interviews, stakeholders reported that:
- Decision-makers adjusted contracting and funding requirements for some proposals to promote hiring of local residents.
- Funding was secured for a community land trust to ensure long-term housing affordability.
To help HIAs be as effective as possible, the report outlined several recommendations for practitioners (individuals and organizations that conduct HIAs), funders, and evaluators, including:
- Ensure that HIA recommendations prioritize determinants of health equity, including identifying ways that policymakers can support community-driven decision-making. Several HIAs examined in this study included recommendations that focused on mechanisms such as creating ongoing community engagement, adopting tools and processes that emphasize the experiences of historically marginalized communities, or establishing funding for community-driven initiatives.
- Ensure that an HIA is appropriate given the practitioner’s stated goals and manage stakeholders’ expectations about what HIAs can achieve. This study demonstrated that HIAs are only one of many factors that inform decision-making. Therefore, practitioners should clearly define with their HIA team and stakeholders what the objectives are and what would constitute success—for example, is the goal policy change or increased community capacity to participate in decision-making?—and evaluate the HIA’s effects according to those objectives.
- Develop a range of recommendations that require various levels of decision-making authority, action, and resources. Providing decision-makers and community members with options can allow some recommendations to move forward even if decision-makers do not want to implement them all.
- Enhance monitoring and evaluation. All HIAs end with a phase for evaluation and monitoring, but practitioners often have limited resources to ensure ongoing measurement of an assessment’s impact and the effects of the final implemented decision. Development and consistent implementation of feasible monitoring plans could yield higher-quality data on outcomes after the HIA.
Despite some data-collection challenges and other limitations, this analysis reinforced previous research demonstrating HIAs’ power to help policymakers consider health equity in decision-making across diverse sectors. More research is needed to determine whether and to what extent HIAs affect determinants of health and health equity over the long term, but these findings nevertheless indicate that HIAs have the potential to contribute to systemic and structural changes that advance positive health outcomes.
- The Pew Charitable Trusts, “HIAs and Other Resources to Advance Health-Informed Decisions: A Toolkit to Promote Healthier Communities Through Cross-Sector Collaboration,” accessed Jan. 27, 2020, www.pewtrusts.org/healthimpactproject/toolkit; E. Bourcier et al., “An Evaluation of Health Impact Assessments in the United States, 2011-2014,” Preventing Chronic Disease 12 (2015): E23, https://www.ncbi.nlm.nih.gov/pubmed/25695261; C. Davenport, J. Mathers, and J. Parry, “Use of Health Impact Assessment in Incorporating Health Considerations in Decision Making,” Journal of Epidemiology and Community Health 60, no. 3 (2006): 196-201, https://jech.bmj.com/content/60/3/196; F. Haigh et al., “What Makes Health Impact Assessments Successful? Factors Contributing to Effectiveness in Australia and New Zealand,” BMC Public Health 15 (2015): 1009, https://bmcpublichealth.biomedcentral.com/articles/ 10.1186/s12889-015-2319-8; Center for Community Health and Evaluation and Human Impact Partners, “Community Participation in Health Impact Assessments: A National Evaluation” (2016), https://humanimpact.org/wp-content/uploads/2018/10/Full-report_Community-Participation-in-HIA-Evaluation.pdf; Health Impact Project, “Is Health Impact Assessment Effective in Bringing Community Perspectives to Public Decision-Making? Lessons From 4 Case Studies in California” (The Pew Charitable Trusts, 2016), https://www.pewtrusts.org/-/media/assets/2016/10/tce_brief.pdf.
- The Pew Charitable Trusts, “Do Health Impact Assessments Help Promote Equity Over the Long Term?” (2020), https://www.pewtrusts.org/en/research-and-analysis/reports/2020/11/do-health-impact-assessments-help-promote-equity-over-the-long-term.
- A.L. Dannenberg, “Effectiveness of Health Impact Assessments: A Synthesis of Data From Five Impact Evaluation Reports,” Preventing Chronic Disease 13 (2016): E84, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4951082/.