WASH Benefits Bangladesh Cluster Randomized Trial

The WASH Benefits Study

Publications from the project can be found by clicking here

Related studies:

WASH Benefits Kenya
Sanitation Hygiene Infant Nutrition Efficacy (SHINE)

Background: During the first two years of life, children born in low-income countries
are at risk for enteric infections due to poor water quality, sanitation conditions, and caregiver handwashing
practices (WASH). During this period, children are also at risk for undernutrition.

Beyond the acute morbidity and suffering caused by enteric infections and undernutrition, observational evidence
also suggests that repeated infections alone and in combination with undernutrition in the first years of life can
have lasting and detrimental effects on longer-term physical growth, cognitive development, and adult human capital.

The WASH Benefits studies provide rigorous evidence on the health and developmental benefits of water quality,
sanitation, handwashing, and nutritional interventions during the first years of life. A cluster-randomized controlled
trial measured the impact of intervention among newborn infants in rural Bangladesh. The study is large in scope
(> 5,000 newborns) and has seven arms (six treatment arms and a control arm). Primary outcomes were measured after
two years of intervention.

Objectives: The goal of the WASH Benefits studies is to generate rigorous evidence about the impacts of
sanitation, water quality, handwashing, and nutrition interventions on child health and development in the first years of
life. The WASH Benefits Bangladesh study is highly comparable to the WASH Benefits Kenya study; both cluster randomized
trials investigated the effects of the same six treatment arms.

The study has three primary scientific objectives:

Measure the impact of sanitation, water quality, handwashing, and nutrition interventions on child health and
development after 2 years of intervention.
Determine whether there are larger reductions in diarrhea when providing a combined water, sanitation and handwashing
intervention compared to each component alone.
Determine whether there are larger effects on growth and development from combining a) daily supplemental nutrition
with b) a combined water, sanitation and handwashing intervention compared to each component alone.

The study has three secondary scientific objectives: (Data is not currently available on ClinEpiDB.org.)

Measure the impact of nutritional supplements and household environmental interventions on environmental enteropathy
biomarkers, and more clearly elucidate this potential pathway between environmental interventions and child growth and development.
Measure the impact of sanitation, water quality, handwashing and nutritional interventions on intestinal parasitic infection
prevalence and intensity.
Measure the association between parasitic infection and other measures of enteric health, including acute diarrhea and environmental
enteropathy biomarkers.

The tertiary scientific objective of the study was to measure the impact of interventions on the following outcomes: (Data is not currently available on ClinEpiDB.org.)

Weight-for-age at 1 and 2 years
Weight-for-height at 1 and 2 years
Underweight at 2 years
Wasting at 2 years
Severe stunting at 2 years
Head circumference-for-age at 1 year and 2 years
Soil-transmitted helminth infection at 2 years
Protozoan infection at 2 years
Verbal Communicative Development Inventory at 1 year
WHO motor milestones at 1 year
Acute respiratory illness
All cause mortality

Methodology:

Geographic Location/Study Sites: The trial was conducted in rural villages in Gazipur, Kishoreganj, Mymensingh, and Tangail districts of Bangladesh. The
majority of the population uses shallow tubewells for drinking water, which are known to be frequently contaminated with fecal indicator bacteria.

Dates of Data Collection: May 2012 - November 2015

Study Design: Cluster-randomized controlled trial with 6 treatment arms and a double-sized control arm. Pregnant women
were enrolled, and outcomes were assessed in the children following 12 and 24 months of intervention.

Eligibility Criteria: The study communities must have met the following criteria:

Rural communities
Drinking water that has low levels of arsenic and iron, but sources are known to be frequently contaminated with
fecal indicator bacteria
Low levels of fully hygienic latrine coverage
Levels of childhood stunting >30%
No previous participation in other studies
Not located in areas completely submerged during the monsoon season

Study Arms: Clusters were randomized to one of 7 study arms. Intervention delivery occurred within 3 months after enrollment of pregnant women, prior
to or as close to birth as possible. Compounds shared a latrine, so sanitation and handwashing interventions were delivered a the compound-level. Nutritional
interventions were delivered directly to the child participant within households.

Water quality: The study delivered a 10-liter insulated water storage vessel with a lid and tap, and a regular supply of free
chlorine tablets (Aquatabs®, sodium dichloroisocyanurate) to households of target children to improve the microbiological quality of their
drinking water. Non-target households in the compound did not receive the water intervention. Behavior change messages were focused on the
consistent provision of treated water to all children living in the household.

Sanitation: The sanitation intervention included three hardware components: (1) All latrines in the compound were replaced or
upgraded to dual pit latrines with a water seal. If the target child's household did not have its own latrine, the project built one. (2) Sani-scoop
hoes dedicated to the removal of human and animal feces from the compound were provided to all households in the compound. (3) Plastic child
potties were provided to all households in the compound that had any children younger than 3 years. The behavior change components of
the intervention emphasized the use of the latrine for defecation and the safe disposal of feces in the compound courtyard to prevent
contact with young children.

Handwashing: The hardware components of the handwashing intervention included two handwashing stations installed in the households
of target children. The first station was located in the kitchen (location of food preparation), and included a 16-liter bucket with a tap
fitting, a stool, bowl and soapy water bottle. The second station was located near the toilet, and included a 40-liter bucket with tap fitting,
stool, bowl and soapy water bottle. The study provided detergent soap to families free of charge to replenish the soapy water bottles. The behavior change component of
the intervention focused messaging for handwashing at critical times: after defecation, after cleaning a child who has defecated, before food preparation,
and before eating or feeding a child.

Water quality + sanitation + handwashing (WSH): Households received all three of the interventions given to the the water quality, sanitation,
and handwashing study arms.

Nutrition: The nutrition intervention targeted target children. Mothers were encouraged to exclusively breastfeed their children
through age 6 months. When newborns reached 6 months of age, mothers were encouraged to continue breastfeeding their children until 24 months,
and received education about supplementing breastfeeding with healthy complementary foods following infant and young child feeding best
practice guidelines from
Unicef and
WHO. Mothers with target children
aged 6-24 months were given 2 10g sachets per day of lipid-based nutrient supplement (LNS), developed and tested through the
iLiNS project, which could be mixed into the child's food.

Water quality + sanitation + handwashing + nutrition (WSHN): Households received all four of the interventions given to the the water quality, sanitation,
handwashing, and nutrition study arms.

Double-sized passive control arm: No intervention.

Units of Data Collection: Each study cluster included a group of proximate household compounds that met eligibility criteria and had
eight eligible pregnant women. More than one cluster could have been enrolled in a single village but clusters needed to be separated from each
other by a minimum of 15 min (1km) walking distance. Households were the family unit of parents and children, and compounds were groups of
households (typically 3-10 households from the same extended family) that share a common courtyard. When multiple pregnant women from a single
compound were eligible for enrollment, more than one household may have been enrolled for that compound. Children who were born to the pregnant
women initially enrolled in the study were considered "target" (or index) children. Children aged <36 months living in the compound at enrollment
and additional children born into study compounds after 6 months were considered "sibling/neighbor" children.

Data Collection: A survey at enrollment (year 0, pre-intervention baseline) measured socioeconomic characteristics and demographics (including maternal
age, maternal education, electricity access, type of floor, and number of people in the household) for each household as well as water, sanitation, and handwashing infrastructure and behaviors
(including type of water source, reported water treatment, defecation location, type of toilet, and presence of water and soap at a handwashing station) for each compound. Adherence to the
interventions was measured by surveying each enrolled compound during visits 1 year post-intervention (midline) and 2 years post-intervention (endline).
Caregiver reported symptoms were assessed for all study children at enrollment, midline, and endline; anthropometry was assessed in target children 1 at midline and endline.

Study Documentation: Analysis protocols and replication files are available on the Open Science Framework

Study protocols:

WASH-b study design and rationale
WASH-b Bangladesh main trial protocol
WASH-b Bangladesh primary outcomes analysis plan updates

Data collection forms: (used to collect raw data)

WASH Benefits, common modules
WASH Benefits Bangladesh, midline & endline survey questionnaires

Codebooks: (describe variables in the "analytic" data files loaded into ClinEpiDB. Analytic variables were cleaned and potentially derived from raw data files by
the WASH Benefits investigators during analysis, and are distinct from the original uncleaned data gathered directly from the data collection forms)

Treatment assignments codebook
Enrollment characteristics codebook
Compound tracking codebook
Adherence codebook
Anthropometry measurements codebook
Diarrhea measurements codebook

Consent forms:

WASH Benefits Bangladesh Main Trial, list of consent forms
WASH Benefits Bangladesh Main Trial, consent forms (English)
WASH Benefits Bangladesh Main Trial, consent forms (Bangla)

ClinEpiDB Data Integration: Data files were provided to ClinEpiDB as flat, csv files. These datasets were merged by unique ID
and redundant or administrative columns were dropped from presentation on ClinEpiDB.org. All dates were dropped to comply with
the ethical conduct of human subjects research.

Acknowledgements: We thank the WASH Benefits Bangladesh study participants and promoters who participated in the trial, the fieldworkers who
delivered the interventions and collected the data for the study, and the managers who ensured that everything ran smoothly.

Financial Support: The WASH Benefits Bangladesh trial was funded by the Bill & Melinda Gates Foundation through a grant to
the University of California, Berkeley (OPPGD759).

Ethics Statement: The study protocol was approved by the Ethical Review Committee at The International Centre for Diarrhoeal Disease Research,
Bangladesh (PR-11063), the Committee for the Protection of Human Subjects at the University of California, Berkeley (2011-09-3652), and the
institutional review board at Stanford University (25863). Participants gave written informed consent before enrollment.

Last Updated: March 8, 2021WASH Benefits Bangladesh was a cluster-randomized trial that assessed improvements in water quality, sanitation, handwashing (WASH interventions) and child nutrition on the primary outcomes of child growth and diarrhea. Geographically matched clusters (groups of household compounds) were randomized to one of six intervention arms (1. water quality, 2. sanitation, 3. handwashing, 4. nutrition, 5. combined water quality + sanitation + handwashing, and 6. combined water quality + sanitation + handwashing + nutrition) or control. Newborns from rural households in Bangladesh were enrolled, and outcomes were measured at 12 and 24 months after intervention delivery.