What is HIA?          see also [Introductory|Introductory Guidance] and  WHO FAQs

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Health impact assessment is the key systematic approach to identifying the differential health impacts of proposed and implemented policies, programmes and projects  within a democratic, equitable, sustainable and ethical framework. So that positive health effects are maximised and negative health effects minimised within an affected community. It uses a range of structured and evaluated sources of evidence that includes public and other stakeholders' perceptions and experiences as well as public health, epidemiological, toxicological and medical knowledge.

The World Health Organisation Gothenburg Consensus definition of HIA is:

“A combination of procedures, methods and tools by which a policy, program or project may be judged as to its potential effects on the health of a population, and the distribution of those effects within the population.”

Other impact assessment approaches include environmental impact assessment, social impact assessment, environmental health impact assessment, technology assessment, strategic environment assessment and health impact analysis, equalities impact assessment and regulatory impact assessment.

What definition of health does it use?

Biomedical Model

Diagnosing and treating diseases and illnesses is one way of thinking about health. The narrow version of the biomedical model - health as the absence of disease - argues that the best way to improve health is to create more and improved health care services e.g. hospitals, medical technology, doctors and nurses, etc.

Social Model

Having a job, feeling good about ourselves, having strong social support networks and relationships as well as income, education and living in clean, safe and pleasing houses and social environments are also important for health. The social model argues that indirect and broader factors have a significant influence on health and hence that the best way to improve health is by dealing with inequalities – poverty, education, poor housing, dirty and disruptive social environments, etc. These tend to be called the wider determinants of health.

Mixed-Model Approach

HIA uses a mixed approach – which is increasingly recognised as the best way forward. It recognises the importance of the biomedical model and the impact on health by specific disease-causing agents e.g. bacteria and viruses and the treatment of them through health care services but it argues that it is the wider determinants which are as important, if not more important, factors in determining the health of individuals and communities.

How do you do it?

There are quite a few models or approaches to doing HIAs. They include:

Bielefeld

British Columbia

East London

Kirklees Metropolitan Council

Merseyside

New Zealand Ministry of Health

Swedish County Council

Tasmania Dept of Health

They are different in that:

Some provide a quick, simple and broad way of thinking through health impacts while others have detailed and precise steps by which health impacts are identified and assessed in an in-depth way.

They are similar in that they have a eight core steps (often named differently but having the same content):

1. Screening:

First, plans, programmes and projects  are assessed to see whether a HIA needs to be done on them. A quick assessment is made on their potential to impact on a community’s health. A HIA may not need to be done either because they have very little impact on health or the health impacts are well known and the mechanisms to reduce them are already in place. This helps ensure that effort and resources are targeted appropriately. The type of HIA that needs to be undertaken is also determined at this stage.

2. Scoping:

Then the ‘terms of reference’ for the HIA are set i.e. what aspects will be considered, what areas and groups might need particular focus and what will be excluded from the HIA, how the HIA process will be managed and so on.

3. Baseline and community profile:

A baseline of the current health and wellbeing of the local and affected community is carried that includes social, economic and environmental conditions.

4. Community involvement:

Key community and professional stakeholders are engaged to feed in their knowledge, expereince and insights on the potential health and wellbeing impacts.

5. Evidence and analysis:

At this step a systematic review of the potential impacts is undertaken and evidence for these impacts collected. An analysis of the likely impacts, the size and significance of the effects and the groups that are likely to be most affected are identified and evidence for these impacts assessed.

6. Mitigation and enhancement:

Measures and options for increasing the potential positive impacts and promoting health (enhancement measures) and those for reducing negative impacts (mitigation measures) are developed.

7. Health impact statement

A report, health impact statement, is written and options with or without recommendations is prepared for to inform and influence desison-makers.

8. Follow up:

At this step ways of monitoring the potential health losses (effects of the negative impacts) and health gains (effects of the positive impacts) as well as mechanisms to evaluate the initiative as a whole are developed. HIAs are also evaluated to assess the accuracy and appropriateness of the health predictions and recommendations made.

What does it do?

HIAs helps to deliver better and improved policy, programm and project outcomes that enhances community and societal health and wellbeing.

It can either be used:

• as an analysis tool that can help forecast the potential negative and positive health consequences

• as a participation tool that can help get residents, local community groups and other stakeholders involved in the design of an initiative

• as a project management tool that can help to structure the development and implementation of policies, programmes, projects and services

• as an evaluation tool to monitor the achievement of stated objectives, outputs and outcomes or those policies, programmes, projects and services

Usually it involves all the four elements described above.

What does it not do?

At the moment HIAs does not give numerical estimates of the negative and positive health impacts. There is no approach at present that allows us to do this accurately. This is because:

• many of the effects on health are not easily measurable

• many effects are indirect and occur over many years

• the methodology to collect quantifiable evidence and make judgements based upon it is currently not well developed

• there is also an important argument that any quantifiable estimates developed would be misleading and give a false sense of reassurance and precision because of the influence of changing social, economic and cultural relationships and the movement of people into and out of communities

Where can you do it?

Areas where HIA has been successfully used include:

• housing
• waste
• transport
• industrial
• mining
• quarrying
• regeneration
• health and social care

When can you do it?

HIAs can be done on policies, programmes and projects.

They can be done at the:

beginning – during the development or pre-development stage

middle – during the implementation stage

end – at the operation or closure stage to look back and evaluate

In HIA terminology – they can be prospective (beginning), concurrent (during) and retrospective (end). Increasingly HIA is seen as a prospective approach.

You can also do quick and broad ones and more long and detailed ones. In HIA terminology you can do a rapid, intermediate or comprehensive HIA.

Who can do it?

HIAs require some knowledge of public health issues but in early design stages just about anyone can do them.

HIA can therefore be built into internal organisational processes and ways of working.

As HIAs have become more complex and resource-intensive there are more and more HIA practitioners in primary health services, universities and independent consultancies.