"a multidisciplinary process
within which a range of evidence about the health effects of a proposal
is considered in a structured framework, …based on a broad model of
health which proposes that economic, political, social, psychological,
and environmental factors determine population health."
and York Public Health Observatory, 2001
- Identify "those activities and policies likely to have major
impacts on the health of a population in order to reduce the harmful
effects on health and to increase the beneficial effects" (Northern
and York Public Health Observatory, 2001).
- Highlight potentially significant health impacts that are either
unknown, under-recognized or otherwise unexpected.
- Facilitate inter-sectoral action for health promotion by bringing
a consideration of health issues into decision-making in other
sectors, for instance in agriculture, education or economic policy.
- Assess distributional effects between population sub-groups,
including existing health disparities, as well as differential
effects of policies on various population sub-groups.
HIA is a new, rapidly evolving field. It has taken on a number of
different forms as it is applied to wide range of issues in diverse
social, political and bureaucratic environments. Variations in HIA
practice have retained several common elements:
Analysis starts with proposed policies or projects;
Comprehensively examines potential health effects;
Based on a broad model of population health;
Employs a multidisciplinary approach to analysis;
Uses a structured framework to consider a range of evidence.
1. Analysis starts with proposed policies
or projects, proceeding from a potential decision or series of
decisions, such as whether to approve or not approve a proposal, whether
an alternative might be preferable, or whether to modify a proposal.
The goal of HIA is to provide unbiased information to policy-makers
and the public, not to make decisions for them based on health criteria
that would trump other social goals. HIA avoids giving a "thumbs up"
or a "thumbs down" for a particular decision, but it will highlight
areas of concern and compare the relative health benefits and costs
of alternatives and/or modifications of the policy. Analyses may be
based on existing data about current or past conditions and trends,
HIA focuses prospectively on the potential consequences of a specific
2. HIA comprehensively
examines health effects. HIA looks squarely and explicitly at
health outcomes. This of course begs the question "What is 'health'?"
The World Health Organization has proclaimed that "'health' is not
just the absence of disease; it is physical, mental and social well-being."
Although scientific rigor can be maintained by narrowly defining research
questions, outcomes and causal relations of interest, in HIA there
is a competing demand for comprehensiveness that places a high value
on addressing potentially significant outcomes even if they are difficult
to ascertain. The appropriate balance between rigor and comprehensiveness
needs to be determined in each HIA, based on the issue being analyzed,
the state of knowledge about the relevant causal relations, the resources
available to conduct the HIA and the information demands of the target
3. HIA is based on a
broad model of population health-one that recognizes the complex,
interacting patterns of determinants that shape the health outcomes
of groups of individuals and the distribution of outcomes within those
groups. This implies several things. First, HIA must consider aggregate
outcomes in the population. Second, HIA usually examines distributional
effects. Third, and most significantly, HIA must take a broad, systems-based
approach to understanding health outcomes and their determinants.
While ultimately it is the individual that experiences good or poor
health, the environmental determinants of health, along with the context
of health outcomes must be considered.
Most approaches to HIA are multidisciplinary. As a broader
range of health determinants is considered, it becomes necessary to
draw from expertise in disciplines outside of health. In our work
we have found that economics plays an especially significant role
as a determinant or modifier of many policies' effects on health.
A multidisciplinary focus is also necessitated by the fact that the
most valuable HIAs examine the effects of proposals in sectors outside
of health, such as agriculture, education and commerce, where health
effects are typically not a major consideration in the policy-making
5. HIA uses a structured
framework to evaluate a range of evidence. Due to variations in
the types of outcomes considered and the substantial uncertainties
involved in assessing potential effects, it becomes necessary to cobble
together an assortment of evidence. Different kinds of criteria may
be used to assess different kinds of evidence in different situations,
which is discussed in the methodology section. What is always important
is that the process for gathering and evaluating evidence is explicit,
transparent and balanced.
A list of Health Impact Assessments conducted in the United States, 1999 - 2007- PDF