About Health Impact Assessment

Health Impact Assessment has been defined as ‘a combination of procedures, methods and tools that systematically judges the potential, and sometimes unintended, effects of a policy, plan, programme or project on both the health of a population and the distribution of those effects within the population. HIA identifies appropriate actions to manage those effects’.

There are two major types of health impact assessment

  1. Policy level HIA
  2. Project level HIA

Health Impact Assessment (HIA) is a systematic way of identifying the potential impacts on the wellbeing and health of the population of any proposed policy, strategy, plan or project, prior to implementation. International experience has found that without an explicit process, such as HIA, the availability of technical information on the expected health and wellbeing impacts is unlikely to be sufficient to influence decision-making to any significant degree.

Once potential impacts have been identified, a set of recommendations for action is prepared, to inform the proposal’s decision-making process. These recommendations are evidence-based and outcomes focused. They propose practical ways to enhance the positive effects of a proposal and to remove or minimise any negative effects. They focus on potential wellbeing and health impacts and the distribution of those impacts across the population, to ensure that no population groups will be disproportionately affected. HIA is therefore an important tool for the goal of reducing inequalities in health.

It can be applied to policy making at central and local government level, and is most effective when used early in the policy development process.

Policy cycle

HIA is undertaken where policy alternatives are being considered but before a commitment has been made.

Where Health Impact Assessment fits into the policy process.

Source: An idea whose time has come (PHAC 2007: p16)

Key benefits of HIA

  • HIA is an effective way to promote wellbeing, health and equity. It increases recognition of the impacts on wellbeing, health and equity of policy from multiple sectors
  • HIA identifies positive aspects of proposals that promote wellbeing, and these can help agencies advocate and fund their proposals
  • HIA can be used as the ‘cement’ to help agencies work together on issues they jointly see as important.
  • HIA helps agencies to be innovative, to think and act broadly and to identify unintended consequences.
  • HIA uses local evidence and published evidence to keep decision makers informed
  • HIA increases understanding of other agencies’ roles

What HIA involves

HIA is a flexible approach which can be modified to fit the particular context and task being assessed. It is scalable – mini, rapid, intermediate, comprehensive – taking into account, timeframes, budgets and resources available.

The four key steps to undertaking a HIA are:

  1. Screening - deciding if and where an HIA might be needed.
  2. Scoping - deciding the parameters for carrying out a HIA.
  3. Appraisal & Reporting identifying and considering the evidence for potential impacts the proposal may have on wellbeing and health and developing specific recommendations for decision makers to improve the proposal, including recommendations for addressing inequalities.
  4. Evaluation – to assess the extent to which recommendations were taken up by policy-makers and whether a positive impact on health was achieved.

Screening tools for stage one, and tools for the rest of the steps, have been developed to assist practitioners with these steps. The key New Zealand resources are the Public Health Advisory Committee publication: A Guide to Health Impact Assessment – 2nd Edition (available in the Ministry of Health Online Catalogue) and the Ministry of Health publication: Whānau Ora Health Impact Assessment.

Who uses health impact assessment

Ideally policy-makers and planners across all public sectors should use HIA for assessing significant policies, programmes and plans. For instance, HIA would assist central government policy analysts and advisors in policy areas such as housing, education, employment, transport or social sectors. And within local government, officials and policy-makers across sectors such as transport, planning, social policy or environment should also find HIA useful.

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