Students in Keshia Pollack Porter’s course “Health Impact Assessment” often have this reaction: Why have I never heard of this useful public health tool?

Health impact assessment, or HIA, refers to a process of studying what might happen to people’s health — defined broadly to include influences such as economic opportunity, education, and community safety — if policy makers, planners or public officials make a particular decision. That might be building a new housing development, changing transportation routes, attempting to save costs on a food assistance program for needy families or instituting a new anti-pollution measure.

Pollack Porter, a professor of health policy and management at the Johns Hopkins Bloomberg School of Public Health, would love for more public health practitioners and policy makers — in every sector — to recognize the term and understand its value.

“The goal is to say, ‘How can we consider health here?’” says Pollack Porter, whose research advances policies that create safe and healthy environments where people live, work, play and travel. “Health impact assessment brings together the best available scientific data and expertise from stakeholders, including the community and policy makers, to identify the potential and often overlooked health effects of policies, projects and programs. HIA also considers equity and how the decision may disproportionately impact certain populations.” 

With that information in hand, decision-makers can move forward or change course. The assessments, Pollack Porter says, not only shine a light on potential harms of starting, ending or scaling back a policy or program, but also how to maximize the health benefits of particular decisions.

Pollack Porter’s course on conducting health impact assessments has given Bloomberg School students hands-on exposure to how the process works. This year, her students worked with the Maryland Environmental Health Network to conduct a health impact assessment of the potential effects of proposals to ban polystyrene containers from Maryland and Baltimore City food-service facilities. 

The environmental impacts of the bills were relatively easy to measure, Pollack Porter says. But it was trickier for the class to find data about how litter affects mental health. Or whether the bill might have the domino effect of boosting food prices or leading to loss of food industry jobs, knowing that employment is among the factors that help determine people’s health and well-being. 

“You realize how little data is out there to make those arguments,” she says. 

On other issues Pollack Porter has assessed, like the wide-ranging health impacts changes to the Farm Bill and federal supplemental nutrition benefits could have for families, there has been more evidence to rely on.

In either case, she says, “It’s up to us as researchers and scientists to present the best unbiased science to influence decision-making.” 

7 Steps to a Health Impact Assessment

1. Screening. Determine if the issue at hand could benefit from a health impact assessment. Is a specific decision being made? Is there enough time to adequately inform the decision?

2. Scoping. Think through the extent of the assessment and your resources and constraints. Health impact assessments can take anywhere from a few weeks to years and involve varying levels of complexity. Do you need to do a rapid assessment to inform an urgent decision, or do you have enough resources and time for a more comprehensive investigation? Can you collect your own data or will you use existing data? How in-depth will your review of the literature be? What are the time and resource constraints? Who are the stakeholders to engage?

3. Assessment. Ask: What is the health of the community — whether a neighborhood or entire country — today? And how might their health be positively or negatively affected if the policy, project or program goes forward?

This stage involves the creation of what Pollack Porter calls a pathway diagram, which visualizes all the ways the policy, program or project being considered might affect the factors that determine health and eventual health outcomes.

4. Recommendations. Develop recommendations for how to move forward or adjust the policy, program or project, based on your assessment and the data and science that inform it.

5. Reporting. Create a written transparent report of the entire HIA process, and disseminate it broadly to decision-makers and community members.

6. Evaluation. Keep tabs on how the HIA was used and its impact on the decision and decision-making process.

7. Monitoring. Track the effects of the proposed policy, project, or program on health outcomes and health determinants.

For those who want to learn more about health impact assessments, Pollack Porter recommends checking out SOPHIA, the Society of Practitioners of Health Impact Assessment.