Kjellstrom et al. make a very valid point by advising that comparative risk assessment (CRA) should be used to describe different health risks according to their common source (or driving source). This new use of CRA would inform about the health impacts of existing policies, such as transport policies, and about important health risks that may be overlooked by these policies.
The authors' recommendation that CRA should be combined with health impact assessment (HIA) outlines the benefits of CRA, but says relatively little about what HIA (HIA) can add to the combination (apart from engaging with stakeholders). This information is relevant for those who may consider using the combination of the two methods and is the focus of this commentary.
HIA is a systematic methodology used to inform about the health relevance of policy decisions. Quantitative assessments of risks, such as CRAs, are used in one of the stages of HIA.
HIA begins by clarifying which policy options are to be compared with respect to their expected health impacts. Those policies are screened to identify whether a need for a health assessment exists. When a health assessment is required, the range of health concerns and issues raised by those policies is identified (scoping), with consideration given to the current scientific knowledge and the concerns and expectations of stakeholders about how the policies may affect their health. These steps allow relevant questions to be identified, and these are then addressed in a stage that involves appraisal of the health impacts. A brief or more detailed appraisal can use a CRA to compare existing quantitative information on health risks. Formal reporting of the results follows, and at this stage, stakeholders again have the opportunity to debate the findings and their implications for decisions on policy options, including mitigation measures. Monitoring of health impacts follows the policy implementation, so that the effectiveness of the process can be assessed and any unexpected results identified.
HIA has parallels with and draws on the experiences of environment and social impact assessments. The procedure involved in a HIA follows the same steps as those in environmental impact assessment and strategic environmental assessment. This process facilitates comparisons with the assessment of other (non-health) impacts of policies. It therefore is suitable for use as one of the safeguards when introducing new policies--for example, as used by development banks in attempts to avoid unwanted effects of investment decisions. It is also a tangible and practical way to pursue healthy public policies (as began in the European Union, see article by Hubel & Hedin in this issue of the Bulletin).
What can HIA (a policy-driven process) contribute in addition to CRA (a science-driven process) when bringing evidence to decision-making? HIA helps to frame and formulate the relevant health questions by examining the situation from a wider base than science alone. It brings transparency to the use of evidence in decision-making, as policy options are clarified and the procedures followed in each step of the assessment can be checked. It facilitates stakeholder debate and participation when the questions to be considered are identified and when the policy options are discussed in view of the results of the health appraisal. …