Several systematic reviews have assessed the impact on health of a range of WASH interventions. The studies reviewed are classified in different ways and include a range of outcome indicators, but the most common of these is diarrhoeal disease morbidity.
The impacts associated with WASH extend beyond health, although in general the evidence is less well developed.
The key points from a review of the evidence on both the health and non-health impacts are presented in this paper. There is also analysis of evidence on delivery mechanisms and evidence on cost effectiveness/ value for money. Finally the evidence paper puts forward analysis of new evidence – what we need to know to do better.