Clinical Trial Details
— Status: Recruiting
Administrative data
NCT number |
NCT05914363 |
Other study ID # |
28307 |
Secondary ID |
424/4 |
Status |
Recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
April 12, 2023 |
Est. completion date |
July 2024 |
Study information
Verified date |
April 2023 |
Source |
London School of Hygiene and Tropical Medicine |
Contact |
Rachel Pullan, PhD |
Phone |
+44 777 2241148 |
Email |
rachel.pullan[@]lshtm.c.uk |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The goal of this intervention study is to learn about the impact of household flooring on
health in rural Kenya, and test whether providing an improved (cement stabilised, washable)
floor improves the health of children and their care providers.
The main questions the study aims to answer are:
- What is the effect of providing a sealed, washable floor on the prevalence of infections
that cause diarrhoea, intestinal worms and sand flea infections?
- To what extent does the intervention reduce contamination of floors with pathogens
within the home?
- What is its effect of the intervention on the wellbeing of caregivers and children?
- Over the course of a year, do the new floors remain undamaged, with no cracks?
- Do participants living with the new floors, and the masons that helped to install the
floors, like them and feel they are practical and affordable?
The study will involve a trial, where half of the recruited households will be randomly
chosen to receive the new floor in addition to some support on how to care for the floor and
keep it clean. The other half of households will not receive anything at first, but at the
end of the research project will also receive a new floor.
Before the new floors are installed, the investigators will make several assessments in all
study households. These will include a survey to measure household characteristics; a stool
survey, to measure how many people are infected with diarrhoea-causing microorganisms and
parasitic worms; a jigger flea examination among children; wellbeing assessments among
children and caregivers; and soil sampling to identify microorganisms on the floor of the
household.
When households receive the new floor, participants will have to move out of their house for
up to 7 days during installation. Participants will also be asked to attend some group
meetings to discuss ways of taking care of the floor and keeping it clean.
Assessments will be repeated 12 months after the floor has been delivered, and additional
interviews will be held with a small number of randomly selected participants. Throughout the
12 months following delivery of the intervention, investigators will make unannounced visits
to households to check the condition of the floor. Participants will also be offered
treatment for parasitic worm infections after assessments have been completed at the start
and end of the project.
Description:
This study is a two-arm household cluster randomised controlled trial (RCT) evaluating the
impact of an improved household flooring intervention on enteric and parasitic infections
among participating households in two contrasting settings in western and coastal Kenya. The
flooring intervention will involve retrofitting a cement-stabilised earth floor that is
sealed, washable and durable and that covers the total interior floor space of a household
dwelling. A key pathway through which an improved floor is expected to reduce exposure to
enteric and parasitic infections is facilitating a more hygienic domestic environment. As
such the proposed intervention would also include a behaviour change component aiming to
promote sustained adoption of appropriate domestic hygiene behaviours. This proposed trial
would be the first of its kind to comprehensively assess the effects of combining improved
flooring technologies with tailored behaviour change programming on a wide range of parasitic
and enteric outcomes, providing an important step towards the establishment of
transformative, community-driven, integrated approaches to WASH-related disease control.
Exploring these relationships across contrasting contexts helps ensure findings will be of
relevance to settings outside Kenya where similar housing, WASH infrastructure and disease
risk are found. Results from this trial will help guide global and national environmental
health priorities, at a time when the WHO is re-evaluating global targets for NTD control and
elimination beyond 2020.
Beyond evaluating the intervention's effects on health outcomes there is a need to understand
how practical the intervention is, and to assess its feasibility and acceptability among
target communities, as these factors will affect how relevant the findings are to control
programmes. Results from the formative research indicate that there may be high levels of
heterogeneity in how household members interact with the floor and adapt their behaviours
such as cooking, animal husbandry and sleeping, all of which may play an important role in
mitigating the success of the intervention. As such a dedicated process evaluation will take
place alongside the RCT to explore implementation fidelity, intervention acceptability, and
how the intervention is integrated into households' daily routines.
- THE INTERVENTION * The first two activities will be conducted in the intervention arm at
month 0, and in the control arm at the end of the study after all data collection is
complete:
1. A low-cost, cement-stablised floor shall be installed in each room of the dwelling
(including kitchen area) to meet the following requirements: (i) non-absorbent,
durable and smooth; (ii) possess good wear resistance; (iii) acceptable appearance;
(iv) be affordable. The proposed structure will consist of a base layer made from
compacted cement-stabilized murram and a final sand and cement mortar finish.
All materials required to build the floor will be provided by the study. Floors
will be installed by trained masons supervised by the investigators, with the
support of additional laborers. Household members will not be expected to
contribute to labour or costs of laying floors, but they will need to vacate their
dwellings for up to 7 days whist floors are laid and cured. The logistics around
this will be discussed in detail with community leaders, and trial participants,
during initial community engagement activities.
2. Group meetings facilitated by the investigators will be held periodically post
intervention to allow households to provide peer support on routines or challenges
relating to living with the new floor and to give space to allow mutually accepted
norms and standards around floor cleaning and maintenance to be established among
intervention households. These group meetings will be complimented by individual
household meetings which will take place at 4 weeks and 8 weeks post intervention,
which will serve to help households develop and adhere to plans around floor
hygiene, personal storage, livestock housing, and cooking arrangements.
3. Annual mass treatment for STH infections (400 mg albendazole) and treatment of
tungiasis in those affected by heavy infections (at 0 and 12 months) according to
county DoH recommendations will be provided in both study arms.
- METHODS * this study will take place in two study sites; one within Kwale county (Dzombo
ward) and the other in Bungoma county (South Bukusu ward and Kabula ward). In each
cluster (i.e., household) all residents will be sampled immediately before and twelve
months post-installation of floors. Faecal samples will be collected from the sampled
population and will be assessed via multiplex PCR for enteric infections (in those aged
under 5 years) and via Kato Katz for STH infections (for those aged >1 year old).
Additional clinical examinations will be performed for tungiasis on all children aged
under 15 years immediately prior to installation of floors, and then at 12-months post
installation.
In addition to these primary outcomes, quality of life measures in enrolled children and
their caregivers will be recorded immediately before and twelve months post-installation of
floors, and environmental sampling will be conducted on floors and surfaces of all enrolled
households 12 months post-installation of floors. Alongside the trial, a process evaluation
will be undertaken to investigate intervention fidelity, acceptability, durability and
practicality. After the endline assessments, all control households will be offered an
improved floor.
Sample size and power calculations are based on the primary outcomes (prevalence of enteric
infections in children under 5 years of age; prevalence of at least STH infection in all
household members over 1 year old; prevalence of tungiasis infection in children under
fifteen years of age) and have been informed by existing data from Kenyan populations. These
include data from the national school-based deworming programme, community-based tungiasis
surveys, and the Global Enteric Multicenter Study (GEMS) study, which was a large
case-control study of moderate to severe diarrhoea in children younger than 5 study that
included Nyanza Province, Kenya.
Enrolled individuals will be clustered within households and calculations are thus based on
the principles of cluster randomised trials, assuming an ICC of 0.1 based on small cluster
size. Effect sizes for tungiasis and STH are based on expert opinion of the smallest
meaningful public health effect. Effect sizes for enteric pathogens are based on earlier WASH
efficiency studies. Tungiasis prevalence will be evaluated per-site while data on STH and
enteric infections will be pooled across-sites.
The primary outcome for which the largest sample size is required is STH prevalence, measured
in enrolled children and their caregivers. Expect STH prevalence is 15% in the control arm
and 10% in the intervention arm. Assuming five enrolled participants per household and a 15%
loss to follow up, 220 households per arm in total across two sites would provide 80% power
to observe this difference at 0.05 significance. This sample size is also sufficient to
detect at 80% power and 0.05 significance: (i) the expected difference in enteric infection
risk in children <5 years old - assuming one <5 year old child per household, and an expected
prevalence post-intervention of 70% in the control arm and 56% in the intervention arm; and
the expected difference in tungiasis prevalence in children <15 years at a site level -
assuming two children <15 per household and an expected prevalence post-intervention of 30%
in the control arm and 15% in the intervention arm.
Based on these estimates, the target sample size is 220 clusters (households) per arm - thus
ensuring 220 children (aged <5 years) and 440 children (aged <15 years) per arm in both
sites.
* ANALYSIS * Analysis of the primary and secondary outcomes for this research question will
be carried out on groups as randomised (intention-to-treat). Results will be presented as
appropriate effects sizes with a measure of precision (95% CIs), using generalised estimating
equations to account for clustering by household. Incidence of caregiver-reported
gastrointestinal illness will be analysed using interrupted time series methods.
Pre-specified faecal indicator bacteria and specific pathogens of interest will be quantified
in each study arm. Generalised linear models with robust standard errors will be used to
estimate differences in overall pathogen prevalence in the dwelling environment at endline.
Data from the caregiver questionnaire will be used to quantify scores on the EQ5D wellbeing
index (caregivers) and the EQ-5D-Y (children only). Generalised linear models with robust
standard errors will be used to estimate differences in wellbeing scores between study arms
at endline. Qualitative data. Data from in-depth interviews with caregivers will be used to
explore different pathways through which the intervention has changed caregiver and child
daily routines and if these changes have wrought any impact on wellbeing. Pre-identified
themes to explore include caregiver self-efficacy, social status, pride, and availability of
free time. Following transcription and translation, data will be coded and analysed
thematically using a case-memo approach. Results will be triangulated with data from the
quantitative caregiver wellbeing questionnaire.