Water, sanitation and hygiene evidence gap map

The purpose of this evidence gap map (EGM) is to provide easy access to the best available evidence on the outcomes of water, sanitation and hygiene (WASH) interventions and to highlight where there are important gaps in the evidence. The EGM identifies a number of systematic reviews assessing the effects of WASH interventions on diarrhoea, but few systematic reviews assess effects on other outcomes such as time use, safety and musculoskeletal injury (particularly for women and girls), and economic outcomes. It also highlights several gaps in the primary evidence base, in particular a lack of prospective impact evidence from Sub-Saharan Africa and studies assessing sanitation and hygiene programs at scale. The EGM is based on a comprehensive search for systematic reviews and impact evaluations. It allows users to explore the findings of 23 systematic reviews through links to user friendly summaries on the 3ie systematic reviews database. It also includes 139 impact evaluation studies of WASH interventions. These impact evaluations collected data on health and non-health impacts, although data were also collected on relevant intermediate outcomes such as access, time use and willingness to pay. The map also aims to capture studies assessing effects of WASH interventions by gender, as it is known that these interventions have different impacts for girls and boys. WASH interventions include water supply, water quality, hygiene and sanitation project interventions and program interventions. This EGM was prepared by the joint efforts of the International Initiative for Impact Evaluation (3ie) and the World Bank's Independent Evaluation Group, with financial support from Japan International Cooperation Agency (JICA). [author abstract]