Interventions promoting uptake of water, sanitation and hygiene (WASH) technologies in low‐ and middle‐income countries: An evidence and gap map of effectiveness studies

Abstract

Background Lack of access to and use of water, sanitation and hygiene (WASH) cause 1.6 million deaths every year, of which 1.2 million are due to gastrointestinal illnesses like diarrhoea and acute respiratory infections like pneumonia. Poor WASH access and use also diminish nutrition and educational attainment, and cause danger and stress for vulnerable populations, especially for women and girls. The hardest hit regions are sub‐Saharan Africa and South Asia. Sustainable Development Goal (SDG) 6 calls for the end of open defecation, and universal access to safely managed water and sanitation facilities, and basic hand hygiene, by 2030. WASH access and use also underpin progress in other areas such as SDG1 poverty targets, SDG3 health and SDG4 education targets. Meeting the SDG equity agenda to “leave none behind” will require WASH providers prioritise the hardest to reach including those living remotely and people who are disadvantaged. Objectives Decision makers need access to high‐quality evidence on what works in WASH promotion in different contexts, and for different groups of people, to reach the most disadvantaged populations and thereby achieve universal targets. The WASH evidence map is envisioned as a tool for commissioners and researchers to identify existing studies to fill synthesis gaps, as well as helping to prioritise new studies where there are gaps in knowledge. It also supports policymakers and practitioners to navigate the evidence base, including presenting critically appraised findings from existing systematic reviews. Methods This evidence map presents impact evaluations and systematic reviews from the WASH sector, organised according to the types of intervention mechanisms, WASH technologies promoted, and outcomes measured. It is based on a framework of intervention mechanisms (e.g., behaviour change triggering or microloans) and outcomes along the causal pathway, specifically behavioural outcomes (e.g., handwashing and food hygiene practices), ill‐health outcomes (e.g., diarrhoeal morbidity and mortality), nutrition and socioeconomic outcomes (e.g., school absenteeism and household income). The map also provides filters to examine the evidence for a particular WASH technology (e.g., latrines), place of use (e.g., home, school or health facility), location (e.g., global region, country, rural and urban) and group (e.g., people living with disability). Systematic searches for published and unpublished literature and trial registries were conducted of studies in low‐ and middle‐income countries (LMICs). Searches were conducted in March 2018, and searches for completed trials were done in May 2020. Coding of information for the map was done by two authors working independently. Impact evaluations were critically appraised according to methods of conduct and reporting. Systematic reviews were critically appraised using a new approach to assess theory‐based, mixed‐methods evidence synthesis. Results There has been an enormous growth in impact evaluations and systematic reviews of WASH ...

Evaluation of an on-site sanitation intervention against childhood diarrhea and acute respiratory infection 1 to 3.5 years after implementation: Extended follow-up of a cluster-randomized controlled trial in rural Bangladesh

“…However, that trial considered the entire data collection period as a single follow-up round and did not assess variation in intervention effects on child health over time. The long-term sustainability of water, sanitation, and hygiene interventions was recently recognized as a significant gap in the existing evidence [ 24 ]. Interventions that depend on individual behavior change may see reduced effectiveness over time as recipients discontinue adherence, as evidenced by a decrease in the average effectiveness of household water treatment interventions over time [ 25 ].…”

Household-level sanitation in Ethiopia and its influencing factors: a systematic review

“…Concurrently, sanitation research has also gained momentum. The volume of primary evidence has increased as several systematic reviews were recently published that primarily assessed the effects of sanitation interventions [ 4 – 9 ].…”

Acceptability measures of water, sanitation and hygiene interventions in low- and middle-income countries, a systematic review

“…Examples of health metrics include diarrheal incidence, worm infections [ 6 , 7 ], treatment outcomes and growth rates in children [ 8 ]. Changes in WASH-related behaviour, and attitudes towards a health outcome are also frequently assessed through self-reported ‘knowledge, attitudes and practice’ surveys [ 9 ]. Other measured outcomes include patient satisfaction [ 10 ], absenteeism and cognitive performance in children [ 8 ].…”

“…To improve impact and sustainability, research focus in the ‘WASH sector’ has recently expanded from investigating ‘which interventions work’ to ‘how they are best implemented’ [ 12 ]. The increased focus on implementation has led to the promotion of community-based behaviour change approaches and the inclusion of psychosocial theory in WASH intervention delivery [ 9 ]. The ‘acceptability’ of an intervention is a key component of implementation [ 13 ].…”