Developing principles for health impact assessment

Background Policies and practice in many sectors affect health. Health impa ct assessment (HIA) is a way to predict these health impacts, in order to r ecommend improvements in policies to improve health. There has been debate about appropriate methods for this work. The Scottish Executive funded the Scottish Needs Assessment Programme to conduct two pilot HIAs and from thes e to develop guidance on HIA. Methods Case study 1 compared three possible future scenarios for developin g transport in Edinburgh, based on funding levels. It used a literature rev iew, analysis of local data and the knowledge and opinions of key informant s. Impacts borne by different population groups were compared using grids. Case study 2 assessed the health impacts of housing investment in a disadva ntaged part of Edinburgh, using published literature, focus groups with com munity groups and interviews with professionals. Results Disadvantaged communities bore more detrimental effects from the lo w transport investment scenario, in the areas of: accidents; pollution; acc ess to amenities, jobs and social contacts; physical activity; and impacts on community networks. The housing investment had greatest impact on reside nts' mental health, by reducing overcrowding, noise pollution, stigma and f ear of crime. Conclusion Although there is no single 'blueprint' for HIA that will be app ropriate for all circumstances, key principles to inform future HIA were de fined. HIA should be systematic; involve decision-makers and affected commu nities; take into account local factors; use evidence and methods appropria te to the impacts identified and the importance and scope of the policy; an d make practical recommendations.