Efficacy and effectiveness of water, sanitation, and hygiene interventions in emergencies in low- and middle-income countries: a systematic review

There are increasing numbers of people affected by natural disasters, disease outbreaks, and conflict. Water, sanitation, and hygiene (WASH) interventions are used in nearly all emergency responses to help reduce disease risk. However, there is a lack of summarized evidence on the efficacy and effectiveness of these interventions. We conducted a systematic review of the published and grey literature on the efficacy and effectiveness of short-term WASH interventions in emergency response in low- and middle-income countries, including: developing theory of change models; setting inclusion criteria; conducting the search; selecting evaluations for inclusion; assessing the quality of the evidence; and analysing the included evaluations. Overall, 15,026 documents were identified and 106 studies describing 114 evaluations met inclusion criteria. Interventions from 39 countries were included. Most included evaluations (77 per cent) had high risk of bias and half were from grey literature (50 per cent). For the m...