Box A7.3: SEA and Health Impact Assessment: similarities and differences

Health Impact Assessment (HIA) is not defined in any international legal instrument, but the International Association for Impact Assessment defines it as:

“… a combination of procedures, methods and tools that systematically judges the potential, and sometimes unintended, effects of a policy, plan, programme or project on the health of a population and the distribution of those effects within the population. HIA identifies appropriate actions to manage those effects.” [13]

There are many similarities between SEA and HIA. Both are intended to inform and influence decision-making. Both use procedures involving screening, scoping and reporting, and both attach great importance to consultation.

But there are also a number of important differences:

• HIA is often applied outside the normal SEA context of “ex-ante” prediction of the effects of strategic proposals such as plans and programmes, for example to identify the effects on health of specific services, activities or behaviour.
• In many contexts, HIA can draw on established knowledge from research in fields such as social sciences, epidemiology and toxicology; this may be more detailed and quantitative than is appropriate for SEA, though HIA can take a strategic and qualitative approach where appropriate.
• In addition, it is worth noting that the health sector sometimes uses terms such as “plan” or “programme” in different senses from those generally understood in SEA (e.g. a plan for reducing health inequalities or a programme of immunization).

Some of the methods used in HIA, and knowledge based on it, can readily be applied in SEA to help identify the potential effects of plans and programmes on human health and health inequalities, and to suggest how adverse effects could be offset and beneficial ones enhanced. As with other environmental effects, however, the predictive character of SEA and the uncertain and indirect nature of many of the health effects of plans and programmes can make it impracticable or even undesirable to attempt precise or detailed predictions.