Health Impact Assessment (HIA)

Health Impact Assessment (HIA) systematically judges the potential health effects of action (such as a policy, plan, program, or project) on the health of a population, and the distribution of those effects within the population. It uses both quantitative and qualitative information, data from population needs assessments, literature reviews of the evidence base, and stakeholders and local people's experience and knowledge.

Overview

HIA has become a major discipline over the past 10 years. There is now a body of international literature on conducting health impact assessments, mainly for large projects. In the UK, a series of practice bulletins are published on HIA. These documents are available from the NHS Health Impact Assessment Gateway [External link] and include the key references "Critical guide to HIA" [External link] and "Practical guide to HIA" [External link].

HIA is intended to help decision-makers by predicting the health consequences if a proposal is implemented. In addition to assessing the health consequences it also produces recommendations as to how the good consequences for health could be enhanced and how the bad consequences could be avoided or minimised.  It aims to predict not only the overall consequences for a population but also the distribution of health impacts in that population i.e. which groups benefit and which groups lose, or at least benefit less.

The principles and methods of HIA can be used to assess health consequences as part of  wider  impact assessment such as a Strategic Environmental Assessment or Environmental Impact Assessment. The HPA may assist NHS stakeholders by providing specialist advice for these assessments.