'Fit for purpose' health impact assessment: a realistic way forward.

The UK government is committed to health impact assessment (HIA) as a means of ensuring that health will be a key consideration in policy formulation and other public decision making. However there has been some debate about whether current HIA practice can reliably inform decision making. In particular consultation with stakeholders and literature reviewing, key tools used in HIA, are said to suffer from a number of conceptual and methodological problems, which can undermine the validity of the assessment. In this paper, we argue that the philosophical nature of HIA, its purpose and its contribution to the promotion of public health is still being established. We outline our own HIA practice, which is based on a broad philosophy of 'fit for purpose' i.e. what is this HIA for and what is its spatial, temporal, social and political context. We suggest that it is important to guard against unrealistic expectations and illusions of total objectivity and precision in the HIA process. HIA 'screening' is capable of delivering benefits by making policies, programmes and projects, more health conscious. Once we move beyond this basic expectation and wish to be able to make judgements about the relative health benefits of alternative courses of action, the potential resource intensiveness of the process increases considerably. Even at a high level of resource usage any conclusions reached through the HIA process will always be, in part, subjective and therefore likely to be contested. We must decide what we want, what we are prepared to legislate for and what we are prepared to pay for in the HIA process.