Promotion of solar water disinfection: comparing the effectiveness of different strategies in a longitudinal field study in Bolivia

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

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 interventions since the International Year of Sanitation, 2008. There are now at least 367 completed or ongoing rigorous impact evaluations in LMICs, nearly three-quarters of which have been conducted since 2008, plus 43 systematic reviews. Studies have been done in 83 LMICs, with a high concentration in Bangladesh, India, and Kenya. WASH sector programming has increasingly shifted in focus from what technology to supply (e.g., a handwashing station or child's potty), to the best way in which to do so to promote demand. Research also covers a broader set of intervention mechanisms. For example, there has been increased interest in behaviour change communication using psychosocial "triggering", such as social marketing and community-led total sanitation. These studies report primarily on behavioural outcomes. With the advent of large-scale funding, in particular by the Bill & Melinda Gates Foundation, there has been a substantial increase in the number of studies on sanitation technologies, particularly latrines. Sustaining behaviour is fundamental for sustaining health and other quality of life improvements. However, few studies have been done of intervention mechanisms for, or measuring outcomes on sustained adoption of latrines to stop open defaecation. There has also been some increase in the number of studies looking at outcomes and interventions that disproportionately affect women and girls, who quite literally carry most of the burden of poor water and sanitation access. However, most studies do not report sex disaggregated outcomes, let alone integrate gender analysis into their framework. Other vulnerable populations are even less addressed; no studies eligible for inclusion in the map were done of interventions targeting, or reporting on outcomes for, people living with disabilities. We were only able to find a single controlled evaluation of WASH interventions in a health care facility, in spite of the importance of WASH in health facilities in global policy debates. The quality of impact evaluations has improved, such as the use of controlled designs as standard, attention to addressing reporting biases, and adequate cluster sample size. However, there remain important concerns about quality of reporting. The quality and usefulness of systematic reviews for policy is also improving, which draw clearer distinctions between intervention mechanisms and synthesise the evidence on outcomes along the causal pathway. Adopting mixed-methods approaches also provides information for programmes on barriers and enablers affecting implementation.

Conclusion

Ensuring everyone has access to appropriate water, sanitation, and hygiene facilities is one of the most fundamental of challenges for poverty elimination. Researchers and funders need to consider carefully where there is the need for new primary evidence, and new syntheses of that evidence. This study suggests the following priority areas:Impact evaluations incorporating understudied outcomes, such as sustainability and slippage, of WASH provision in understudied places of use, such as health care facilities, and of interventions targeting, or presenting disaggregated data for, vulnerable populations, particularly over the life-course and for people living with a disability;Improved reporting in impact evaluations, including presentation of participant flow diagrams; andSynthesis studies and updates in areas with sufficient existing and planned impact evaluations, such as for diarrhoea mortality, ARIs, WASH in schools and decentralisation. These studies will preferably be conducted as mixed-methods systematic reviews that are able to answer questions about programme targeting, implementation, effectiveness and cost-effectiveness, and compare alternative intervention mechanisms to achieve and sustain outcomes in particular contexts, preferably using network meta-analysis.

Water, sanitation and hygiene (WASH) behaviour change research: why an analysis of contingencies of reinforcement is needed

Diarrheal disease associated with poor water, sanitation and hygiene (WASH) kills more than one million people every year. Safe WASH practices have the potential to greatly reduce these statistics but behaviour change interventions in the field have yielded little success to date. Currently, there is an emphasis on addressing cognitive processes to bring about changes in behaviour. In this review, a case is made for the benefits of a contingency-based perspective, focusing on the contextual antecedents and consequences of behaviour. The role of contingencies of reinforcement, not explored in previous WASH literature, is discussed as an explanatory framework for designing behaviour change strategies. A proper use of contrived reinforcers is recommended to counterbalance the natural reinforcers of convenience associated with risk practices. Recognising the role of consequences in the acquisition and maintenance of behaviour is an important step in the search for the answers urgently needed in the WASH field.

A Transdisciplinary Methodology for Introducing Solar Water Disinfection to Rural Communities in Malawi-Formative Research Findings

Despite the increasing volume of evidence demonstrating the efficacy of solar water disinfection (SODIS) as a household water treatment technology, there still appear to be significant barriers to uptake in developing countries. The potential of SODIS is often treated with skepticism in terms of effective treatment, volume, and safety, and is dismissed in preference for more accepted technologies such as ceramic filters and dose chlorination. As part of WATERSPOUTT (EU H2020 688928), our study used a transdisciplinary methodology to cocreate an innovative SODIS system in rural Malawi. The formative work focused on the design of 1) an appropriate and acceptable system and 2) a context-specific intervention delivery program using a behavior-centered design. Initial research identified specific water needs and challenges, which were discussed along with a cocreation process with potential end users, through a series of shared dialogue workshops (SDWs). Specifications from end users outlined a desire for higher volume systems (20 L) that were "familiar" and could be manufactured locally. Development of the "SODIS bucket" was then undertaken by design experts and local manufacturers, with input from end users and subject to controlled testing to ensure efficacy and safety. Concurrent data were collated using questionnaires (n = 777 households), water point mapping (n = 121), water quality testing (n = 46), and behavior change modeling (n = 100 households). These identified specific contextual issues (hydrogeology, water access, gender roles, social capital, and socioeconomic status), and behavioral determinants (normative, ability, and self-regulation factors) that informed the development and delivery mechanism for the implementation toolkit. Integr Environ Assess Manag 2020;16:871-884. © 2020 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Improving Complementary Food Hygiene Behaviors Using the Risk, Attitude, Norms, Ability, and Self-Regulation Approach in Rural Malawi

The study evaluated the effectiveness of an intervention to improve complementary food hygiene behaviors among child caregivers in rural Malawi. Formative research and intervention development was grounded in the risk, attitude, norms, ability, and self-regulation (RANAS) model and targeted washing hands and kitchen utensils with soap, safe utensil storage, reheating of leftover food, and feeding of children by caregivers. Longitudinal research was applied at baseline and follow-up surveys among 320 caregivers. Determinants of selected behaviors were found, and interventions were developed based on the behavior change techniques aligned with these determinants in the RANAS model. The intervention was delivered over 9 months through group (cluster) meetings and household visits and included demonstrations, games, rewards, and songs. We randomly assigned villages to the control or intervention group. Follow-up results indicated a significant increase in three targeted behaviors (washing kitchen utensils with soap, safe utensil storage, and handwashing with soap) among intervention recipients. Several psychosocial factors differed significantly between the intervention and control groups. Mediation results showed that the intervention had a significant effect on these three targeted behaviors. For handwashing, feelings, others' behavior in the household, and remembering; for washing kitchen utensils, others' behavior in the household and difficulty to get enough soap; for safe utensils storage, others' behavior in the village and remembering mediated the effect of the intervention on the targeted behaviors. The study demonstrated that targeting food hygiene behaviors with a theory-driven behavior change approach using psychosocial factors can improve the behavior of child caregivers in rural Malawi.

Identifying behavioural determinants for interventions to increase handwashing practices among primary school children in rural Burundi and urban Zimbabwe

BACKGROUND

This article presents the development of a school handwashing programme in two different sub-Saharan countries that applies the RANAS (risk, attitudes, norms, ability, and self-regulation) systematic approach to behaviour change.

METHODS

Interviews were conducted with 669 children enrolled in 20 primary schools in Burundi and 524 children in 20 primary schools in Zimbabwe. Regression analyses were used to assess the influence of the RANAS behavioural determinants on reported handwashing frequencies.

RESULTS

The results revealed that, in both countries, a programme targeting social norms and self-efficacy would be most effective. In Burundi, raising the children's perceived severity of the consequences of contracting diarrhoea, and in Zimbabwe, increasing the children's health knowledge should be part of the programme.

CONCLUSIONS

The school handwashing programme should create awareness of the benefits of handwashing through educational activities, raise the children's ability and confidence in washing hands at school through infrastructural improvements, and highlight the normality of washing hands at school through events and poster creation.

Solar water disinfection (SODIS): a review from bench-top to roof-top

Solar water disinfection (SODIS) has been known for more than 30 years. The technique consists of placing water into transparent plastic or glass containers (normally 2L PET beverage bottles) which are then exposed to the sun. Exposure times vary from 6 to depending on the intensity of sunlight and sensitivity of the pathogens. Its germicidal effect is based on the combined effect of thermal heating of solar light and UV radiation. It has been repeatedly shown to be effective for eliminating microbial pathogens and reduce diarrhoeal morbidity including cholera. Since 1980 much research has been carried out to investigate the mechanisms of solar radiation induced cell death in water and possible enhancement technologies to make it faster and safer. Since SODIS is simple to use and inexpensive, the method has spread throughout the developing world and is in daily use in more than 50 countries in Asia, Latin America, and Africa. More than 5 million people disinfect their drinking water with the solar disinfection (SODIS) technique. This review attempts to revise all relevant knowledge about solar disinfection from microbiological issues, laboratory research, solar testing, up to and including real application studies, limitations, factors influencing adoption of the technique and health impact.

Systematic review of behavior change research on point-of-use water treatment interventions in countries categorized as low- to medium-development on the human development index

Point-of-use water treatment (i.e., water purification at the point of consumption) has proven effective in preventing diarrhea in developing countries. However, widespread adoption has not occurred, suggesting that implementation strategies have not motivated sustained behavior change. We conducted a systematic literature review of published behavioral research on factors influencing adoption of point-of-use water treatment in countries categorized as low- to medium-development on the United Nations Development Programme Human Development Index. We used 22 key words to search peer-reviewed literature from 1950 to 2010 from OVID Medline, CINAHL, and PsycINFO. Twenty-six (1.7%) of 1551 papers met our four inclusion criteria: 1) implemented a point-of-use water treatment intervention, 2) applied a behavioral intervention, 3) evaluated behavior change as the outcome, and 4) occurred in a low- or medium-development country. We reviewed these 26 publications for detailed descriptions of the water treatment intervention, theoretical rationales for the behavioral intervention, and descriptions of the evaluation. In 5 (19%) papers, details of the behavioral intervention were fully specified. Seven (27%) papers reported using a behavioral theory in the design of the intervention and evaluation of its impact. Ten (38%) studies used a comparison or control group; 5 provided detailed descriptions. Seven (27%) papers reported high sustained use of point-of-use water treatment with rates >50% at the last recorded follow-up. Despite documented health benefits of point-of-use water treatment interventions in reducing diarrheal diseases, we found limited peer-reviewed behavioral research on the topic. In addition, we found the existing literature often lacked detailed descriptions of the intervention for replication, seldom described the theoretical and empirical rationale for the implementation and evaluation of the intervention, and often had limitations in the evaluation methodology. The scarcity of papers on behavior change with respect to point-of-use water treatment technologies suggests that this field is underdeveloped.

Sustainable use of arsenic-removing sand filters in Vietnam: psychological and social factors

Elevated arsenic concentrations in drinking water pose a health threat to millions of people. Although point-of-use sand filters provide an effective technical solution for mitigating arsenic exposure, the actual reduction in health risk also depends on psychological factors that influence behaviors related to this device. For example, acquiring a sand filter must be preferred to competing options for investing effort and money and, once installed, the users must regularly maintain the filters. These key behaviors of sustainable use are related to psychological factors, such as problem awareness, benefits and costs, social and affective influences, and the perception of practical difficulties. This study investigated the sustainable use of arsenic-removing sand filters in Vietnam. Based on questionnaire surveys, data were gathered in 319 rural households and analyzed with regression models. Psychological factors explained significant variance in the investigated key behaviors. Significant factors included perceived improvements in water healthiness and taste, monetary costs, social norms, and affective influences. In questions with open answers, interviewees mentioned various practical problems, particularly those related to the inflexibility of the device and the effort of changing the sand. Interestingly, many interviewees operate the sand filters for removing iron from the water but are unaware of problems with arsenic.

Factors associated with compliance among users of solar water disinfection in rural Bolivia

BACKGROUND

Diarrhoea is the second leading cause of childhood mortality, with an estimated 1.3 million deaths per year. Promotion of Solar Water Disinfection (SODIS) has been suggested as a strategy for reducing the global burden of diarrhoea by improving the microbiological quality of drinking water. Despite increasing support for the large-scale dissemination of SODIS, there are few reports describing the effectiveness of its implementation. It is, therefore, important to identify and understand the mechanisms that lead to adoption and regular use of SODIS.

METHODS

We investigated the behaviours associated with SODIS adoption among households assigned to receive SODIS promotion during a cluster-randomized trial in rural Bolivia. Distinct groups of SODIS-users were identified on the basis of six compliance indicators using principal components and cluster analysis. The probability of adopting SODIS as a function of campaign exposure and household characteristics was evaluated using ordinal logistic regression models.

RESULTS

Standardised, community-level SODIS-implementation in a rural Bolivian setting was associated with a median SODIS use of 32% (IQR: 17-50). Households that were more likely to use SODIS were those that participated more frequently in SODIS promotional events (OR=1.07, 95%CI: 1.01-1.13), included women (OR=1.18, 95%CI: 1.07-1.30), owned latrines (OR=3.38, 95%CI: 1.07-10.70), and had severely wasted children living in the home (OR=2.17, 95%CI: 1.34-3.49).

CONCLUSIONS

Most of the observed household characteristics showed limited potential to predict compliance with a comprehensive, year-long SODIS-promotion campaign; this finding reflects the complexity of behaviour change in the context of household water treatment. However, our findings also suggest that the motivation to adopt new water treatment habits and to acquire new knowledge about drinking water treatment is associated with prior engagements in sanitary hygiene and with the experience of contemporary family health concerns.Household-level factors like the ownership of a latrine, a large proportion of females and the presence of a malnourished child living in a home are easily assessable indicators that SODIS-programme managers could use to identify early adopters in SODIS promotion campaigns.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00731497.

Why Do People Stop Treating Contaminated Drinking Water With Solar Water Disinfection (SODIS)?

Solar Water Disinfection (SODIS) is a simple method designed to treat microbiologically contaminated drinking water at household level. This article characterizes relapse behavior in comparison with continued SODIS use after a 7-month nonpromotion period. In addition, different subtypes among relapsers and continuers were assumed to diverge mainly in their intention to use SODIS and their degree of cognition intensity. Data were taken from a longitudinal SODIS promotion study. Cluster analyses were applied to find subtypes among 166 relapsers and 123 continuers. Overall relapsers have lower values for all psychological variables compared to overall continuers. A low-value and a high-value relapser subtype as well as a low-value and a high-value continuer subtype were found. Low-value relapsers differ from high-value relapsers in one central belief (taste), in affective connotation, social norms, and dissonance. Interestingly, high-value relapsers have values almost as high as low-value continuers, differing only in their degree of habit. Only high-value continuers seem to be stable and did not show a decrease in critical habit variables over time. The different subtypes are placed along the behavior change process, and possible interventions for each type are highlighted.