Sustained adoption of water, sanitation and hygiene interventions: systematic review.

OBJECTIVE: To understand factors that influence sustained adoption of water, sanitation and hygiene (WASH) technologies or behaviours. METHODS: Systematic review of the current literature. Articles were gathered from databases of peer-reviewed articles and grey literature, and screened for relevance. After exclusion, we created a descriptive map of 148 articles and analysed in-depth 44 articles that had an explicit focus on promoting or evaluating sustained adoption or programme sustainability. Twenty-two of these articles met our definition of measuring sustained adoption. RESULTS: Definitions of sustained adoption varied widely and were often inadequate, making comparison of sustained adoption across studies difficult. The time frame for measurements of sustained adoption is frequently inadequate for examination of longer-term behaviour change. CONCLUSIONS: Ideally, an evaluation should specify the project period and describe the context surrounding adoption, make measurements at multiple time points, diversify measurement methods and describe and measure a range of factors affecting sustained adoption. Additional consideration needs to be given to developing behaviour change models that emphasise factors related to sustained adoption, and how they differ from those related to initial adoption.