WASH Benefits Kenya Cluster Randomized Trial

The WASH Benefits Study

Publications from the project can be found by clicking here

Related studies:

WASH Benefits Bangladesh
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 provides 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 Kenya. The study is large in scope
(> 7,000 newborns) and has eight arms (six treatment arms and two control arms). 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 Kenya study is highly comparable to the WASH Benefits Bangladesh 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 areas of 10 districts in Bungoma, Kakamega and Vihiga counties in the western
part of Kenya. The region is populated mainly by subsistence farmers. Unimproved latrine coverage is high (at least 85%). A pilot study in the region
estimated that among children <27 months old, 11% had diarrhea in the preceding 2 days. Very few (<5%) households had piped water and the majority of households
reported obtaining drinking water from sources where chlorination has previously been shown to be effective (such as protected springs).

Dates of Data Collection: November 2012 - May 2014

Study Design: Cluster-randomized controlled trial with 6 treatment arms, a passive control arm, and a double-sized active 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 (defined as villages with <25% of residents living in rental houses, <2 gas/petrol stations and <10 shops)
Not enrolled in ongoing water, sanitation, hygiene, or nutrition programs
Most of the population relied on communal water sources and had unimproved sanitation facilities
At least six eligible pregnant women in the cluster at baseline

Study Arms: Clusters were randomized to one of 8 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 installed chlorine dispensers within the cluster boundary at public water sources used by study participants.
All community members were also able to use the dispensers. After filling their water collection container (typically a 20 L plastic jerry can) at the
source, users could place the container under the dispenser and turn a knob to release 3 mL of 1.25% sodium hypochlorite, an amount designed to yield
2 mL/L of free chlorine residual after 30 min for 20 L of water. The study also included community level promotion of dispenser use and all households
in the study compound received bottles of sodium hypochlorite (6 months' supply) to facilitate householders' water treatment during periods when they
rely on rainwater harvesting (common during the rainy season) or if they use a water source in which a dispenser has not been installed. Households were
visited monthly by community-based health promoters.

Sanitation: The sanitation intervention included three hardware components: (1) All existing latrines in the compound were
upgraded by installing a plastic slab with a tight-fitting lid. Households without latrines or with poor qualiity latrines were provided with
a new dual pit latrine. (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. Households were visited monthly by community-based health promoters.

Handwashing: The hardware components of the handwashing intervention included two handwashing stations installed in all households.
The first station was located in the kitchen (location of food preparation) and the other located near the toilet. Handwashing stations were constructed from locally available materials and included
a dual tippy-tap design with independent pedals attached to two 5 L jerry cans of clean water and soapy water. 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 two critical times:
after defecation and before food preparation. Households were visited monthly by community-based health promoters.

Water quality + sanitation + handwashing (WSH): Households received all three of the interventions given to the the water quality, sanitation,
and handwashing study arms, and were visited monthly by community-based health promoters.

Nutrition: 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.
From ages 6 - 24 months, study children received a daily lipid-based nutritional supplement (LNS) that has been developed and tested
through the iLiNS project. The study also provided LNS to older, age-eligible siblings (6-24 months)
living in study households to prevent potential sharing of LNS with older siblings. Households were visited monthly by community-based health promoters.

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, and were visited monthly by community-based health promoters.

Double-sized active control arm: Households did not receive any intervention, but were visited monthly by community-based health promoters.

Passive control arm: Households did not receive any intervention and were not visited by community-based health promotors.

Units of Data Collection: Clusters consisted of 1 or more administrative villages; two or more neighboring may have been combined to create 1 cluster as
long as the cluster of villages had at least 8 eligible pregnant women and shared a border. Households were the family unit of parents and children, and compounds
were groups of households (typically 1-4 households from the same extended family). When multiple pregnant women from a single compound were eligible for
enrollment, more than one household may have been enrolled for that compound. Data about each compound were collected from households belonging to
that compound, and responses from various households about that compound's characteristics may differ.
Children who were born to the pregnant women initially enrolled in the study were
considered "target" 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 household socioeconomic characteristics and demographics (including maternal
age, maternal education, electricity access, type of floor, and number of people in the 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). Adherence to the
interventions was measured by surveying each enrolled household during unannounced visits 1 year post-intervention (midline) and 2 years post-intervention (endline).
Caregiver reported symptoms were assessed at enrollment, midline, and endline; anthropometry was assessed 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 Kenya main trial protocol
WASH-b Kenya primary outcomes analysis plan updates

Data collection forms: (used to collect raw data)

WASH Benefits, common modules
WASH Benefits Kenya, uptake assessment (adherence) forms

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
Compound tracking codebook
Baseline adherence codebook
Midline adherence codebook
Endline adherence codebook
Midline anthropometry measurements codebook
Endline anthropometry measurements codebook
Diarrhea measurements codebook
Negative control measurements codebook
Mortality codebook

Consent forms:

WASH Benefits Kenya Main Trial, consent forms (English)
WASH Benefits Kenya Main Trial, consent forms (Kiswahili)
WASH Benefits Kenya Main Trial, consent forms (Luhya)

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 Kenya 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 Kenya trial was funded by a grant from the Bill & Melinda Gates Foundation (OPPGD759) and
a grant from United States Agency for International Development (USAID) to Innovations for Poverty Action (AID-OAA-F-13-00040).

Ethics Statement: The study protocol was approved by the Committee for the Protection of Human Subjects at the University of California, Berkeley
(protocol number 2011-09-3654), the institutional review board at Stanford University (IRB-23310), and the scientific and ethics review unit at
the Kenya Medical Research Institute (protocol number SSC-2271). Under direction of the study investigators, Innovations for Poverty Action (IPA)
was responsible for intervention delivery and data collection. Participants gave written informed consent before enrollment.

Last Updated: March 8, 2021WASH Benefits Kenya 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 two control arms (1. active, and 2. passive). Newborns from rural households in Kenya were enrolled and outcomes were measured at 12 and 24 months after intervention delivery.