Preliminary results suggest that after 2 years, the Phase 1 program achieved a

46% reduction in diarrhoea in children under 5, a 73% reduction in household

air pollution for families cooking outdoors, and a 27.7% reduction in cookstove

emission exposure among children. If similar reductions are sustained

throughout Phase 2, this program may save more than 30 children’s lives a year,

and avert over 2,500 disability-adjusted life-years (DALYs) annually.

Cluster-randomized controlled trial to evaluate the Rwanda Ministry of Health and DelAgua Health “Tubeho Neza” large-scale distribution

of cookstoves and water filters in Western Province, Rwanda

ABSTRACT

DelAgua Health, a social enterprise, partnered with the Rwanda Ministry of

Health (MOH) in 2012 to distribute water filters and improved cookstoves to

the poorest 25% of families in Rwanda (socioeconomic Ubudehe levels 1 and

2). More than 100,000 low-income households in 72 of 96 randomly selected

sectors of Western Province received improved cookstoves and advanced

water filters in the fall of 2014.

The leading causes of death in children under 5 in Rwanda are ALRI (16%) and

diarrhoea (9%). There are over 22,000 deaths of children under 5 a year in

Rwanda (UNICEF 2014). The existing Tubeho Neza Phase 2 program in Rwanda

has reached nearly 460,000 people, including over 140,000 children under 5.

DelAgua Health has sponsored an independent evaluation of the health

impacts of this program, run by the London School of Hygiene and Tropical

Medicine, Emory University, Oregon Health Science University, and Portland

State University. The research team is undertaking a cluster-randomized trial

to evaluate the intervention in terms of coverage, use, exposure and health.

reduction in diarrhoea in children under 5

Phase 1

Phase 2 reached nearly

people, including

children under 5

46% 460,000 Potential for saving

and

per year

30 lives

140,000 2,500 DALYs

Distribution to the poorest

25% of Rwandan families,

more than

100,000 households

Thomas Clasen, JD, PhD

London School of Hygiene & Tropical

Medicine, Emory University

Corey Nagel, PhD, RN, MPH

Oregon Health and Science University

Evan Thomas, PhD, PE, MPH

Portland State University, DelAgua Health

1. BACKGROUND

Environmental contamination at the household level is a major cause of death

and disease, particularly among rural populations in low-income countries.

Household air pollution (HAP) contributes to acute lower respiratory infection

(ALRI), the leading cause of death in children under 5; among adults, HAP

is a risk factor for ischaemic heart disease, stroke, hypertension, chronic

obstructive pulmonary disease, lung cancer, trachea, bronchus, cerebrovascular

disease and cataracts (Gordon 2014; Smith 2014; Clark & Peel 2014).

Collectively, pneumonia and diarrhoea are responsible for an estimated 6.9

million deaths annually (The Lancet Diarrhoea and Pneumonia Interventions

Study Group 2012). In Rwanda, 99.0% of rural householders cook with biomass,

mainly on open three-stone fires, and only 2.2% have water on their premises

(Rwanda DHS).

Despite clear evidence that HAP and unsafe drinking water are important risk

factors, there is limited evidence of the health impact of improved cookstoves

that can deployed at scale among vulnerable populations (Smith 2011). Trials

are currently underway to explore the effectiveness of locally-made low-tech

rocket stoves (Dickinson 2015), improved biomass stoves (Boamah 2014),

imported Philips® gasifier stove (Dickenson 2015), biomass stoves with

chimney (Tielsch 2014), LPG stoves (Tielsch 2014; Boamah 2014) and ethanol

stoves. Significantly, however, these are all limited scale efficacy trials. Similarly,

although household water filters have been in more than a dozen efficacy

trials, evidence of their effectiveness is still limited (Clasen 2015). The up-front

cost of household filters and stoves has limited the extent to which they have

been scaled up, particularly in rural settings. Carbon credit financing offers

the potential to provide these technologies to vulnerable populations and to

encourage their actual adoption and use on a long-term basis (Hodge & Clasen

2014).

Inadequate and unsafe drinking water is the leading cause of diarrheal disease,

which alone accounts for more than 500,000 deaths annually in children under

5 years in low-income countries (Pruss 2014).

In Rwanda

99.0% of rural householders cook

with biomass

Only

2.2% have water on their

premises

2. INTERVENTION AND PILOT STUDIES

The intervention consists of the free distribution of cookstoves and water

filters and the continued monitoring and promotion of their use. The cookstove

is the EcoZoom™ Dura, a “rocket stove” that concentrates the combustion

process while channeling airflow to more completely burn the combustible fuel

provided. Comparison of cookstoves in Uganda, Kenya and Tanzania reported

that the EcoZoom (aka StoveTec) stove saved 39% to 54% of fuel compared

to open fires, cooked meals faster, and was participant’s most preferred stove

during controlled cooking of local dishes (Adkins 2010). The water filter is the

Vestergaard Frandsen Lifestraw Family™ 2.0, a point-of-use microbial water

treatment system designed for household use in resource-limited settings.

The unit treats up to 18,000 liters of water, which can supply a family of five

with clean drinking water for three to five years, and exceeds the World

Health Organization’s (WHO) “highly protective” standard for household

water treatment technologies (Clasen 2009). The intervention is promoted

by initial and regular follow-up visits by community health workers (CHWs)

hired by the MOH that are trained and compensated for their time on the

project by the implementer. Population representative household surveys are

undertaken semiannually to assess stove and filter coverage and use as part of

the implementer application to secure carbon credits through the UN-backed

Clean Development Mechanism.

The implementer first undertook a pilot intervention (Phase 1) to

approximately 2,200 households in 15 rural villages (Barstow 2014). We

undertook a five-month cluster randomized trial among 566 households in

three pilot villages to assess coverage and use, the impact of the water filter

on faecal indicator bacteria in household drinking water and the impact of the

stove on fine particulate matter (PM2.5) and carbon monoxide (CO) in reported

cooking areas (Rosa 2014). While reported filter use was high (89.2%), 25%

reported drinking from other sources at least once during 5 follow-up visits;

filter-mounted sensors also showed self-reports to exaggerate use (Thomas

2014). Overall, the intervention was associated with a 97.5% reduction in mean

faecal indicator bacteria (Williams mean 0.5 vs. 20.2 TTC/100 mL, p<0.001).

Two-thirds (66.7%) of intervention households identified the intervention

stove as their main cooking stove, but only 23.3% of intervention households

reported that their main cooking area was outdoors. Overall, the stoves were

associated with a 48% reduction of 24-h PM2.5 concentrations in the cooking

area (267 µg/m3 vs. 509 µg/m3, p=0.005). The reduction was 37% for those

cooking indoors (p=0.08) and 73% for those cooking outdoors (p<0.001) (Rosa

2014).

EcoZoom stove saves

39%–54% of fuel compared to open fires

LifeStraw filter can supply a family of 5 with clean drinking water for

3–5 years

Individual household visits play a crucial role in educating people about the benefits of the equipment.

Following the pilot RCT, 9 of the non-RCT pilot villages were matched with

control villages and followed for an additional 12 months to assess longer-

term intervention uptake and to test methods for assessing exposure and

health outcomes for a larger scale health impact evaluation. Households were

surveyed once in round 1, 12–18 months after first receiving the intervention,

and a second time six months later. In round 1, 113 intervention and 156

control households were enrolled and surveyed; 91 of these intervention and

144 of these control households were followed up approximately six months

later in round 2. Results from this follow-up study are preliminary and have

not yet been submitted to peer review. In both rounds, 82% of intervention

households still had the filter that was reported to be working properly, and

more than 95% of intervention houses still had the Ecozoom stove. In both

rounds, 90% of intervention households reported currently using the filter, 95%

of whom within the previous two days; usage was similar with the Ecozoom

stove, with at least 87% of intervention households reporting current usage

in both rounds, 95% of whom within the last two days. Among intervention

households that had drinking water in the house at time of visit, 74% in round

1 reported the water had been treated (99% using the filter), and 78% in round

2 (97% with the filter). Using combined data from both rounds, the filters were

associated with a 79% reduction in mean faecal indicator bacteria (geometric

mean 1.3 vs. 6.3 TTC/100 mL, p<0.001). The odds of having contaminated

drinking water (>=1 TTC/100mL) were 3.7 times higher in the control arm

than the intervention arm (p<0.001). In order to assess the impact of the

Ecozoom stove on reducing exposure to harmful cooking smoke, we measured

personal exposure to particulate matter (PM2.5) in cooks and children under

5 for a 48-hour period. Intervention cooks had a reduced exposure of 26.5%

(p=0.01) compared to controls (predicted mean 198.9 vs. 270.6 µg/m3), while

intervention children under 5 had a reduced exposure of 27.7% (p<0.001,

predicted mean 219.1 vs. 303.0 µg/m3).

While this study was not designed to assess health impact, primary caretakers

were asked to report on their child’s health in the previous seven days (n=338

children in round 1, 305 in round 2). One week prevalence of diarrhoea among

children under 5 was reduced by 46% (12.4% vs. 19.0%, p=0.04). No impact

has been observed in the prevalence of proxy indicators for ALRI. Though the

results of this follow up study are preliminary, indications are that the program

achieved high uptake and sustained use of a household water filter and

advanced cookstove 1–2 years following intervention delivery, with evidence

of water quality improvement, smoke exposure reductions, and improvements

in child health outcomes.

One week prevalence of diarrhoea among children

under 5 was reduced by

46%

3. CURRENT RESEARCH

Based on the initial results, the Rwanda MOH and DelAgua elected to scale

up the intervention to cover the poorest third of the population (ubudehe

1 and 2) throughout all of Western Province (Phase 2). The implementation

plan called for delivery to 72 of the 96 sectors (groups of villages that also

correspond with catchment areas for primary care clinics), with the balance to

be covered approximately one year later. As the MOH and DelAgua agreed to

select the initial round randomly to ensure equity, we took advantage of this

natural experiment to conduct a sector-level cluster-randomized controlled

trial to assess the impact of the intervention on health outcomes using records

maintained by the clinics and CHWs (the “clinic-level RCT”). At the same time,

we randomly selected 87 villages from each arm of the sector-level RCT for

a nested village-level RCT where we could assess coverage, uptake (use),

exposure and other measures of health outcomes (reported, CHW recorded,

instrumented and potential blood-based biomarkers) (the “village-level RCT”).

Following our baseline study, the implementer delivered the intervention to

approximately 100,000 eligible households within the 72 intervention sectors

(September–December 2014).

3.1 Clinic-level RCT

The main objective of the clinic-level RCT is to assess the impact of the

intervention on health. The study is among the largest RCTs ever conducted

in environmental health and includes all 96 sectors (~3700 villages and

approximately 140,000 ubudehe 1 and 2 households) in Western Province.

The main advantages of this trial over previous research are (i) its use of more

objective health data drawn from clinical records with no potential bias arising

from self-reported conditions recorded on multiple visits by enumerators; (ii)

its ability to investigate a wide variety of health outcomes potentially related

to water quality and HAP, including not only ALRI and diarrhoea (all cause

mortality, mortality attributed to respiratory disease or diarrheal disease,

tuberculosis, hypertension, low birthweight, premature birth and stillbirth),

and (iii) its assessment of a programmatically-delivered intervention at scale,

rather than a research-driven efficacy study. We worked closely with the MOH

on data entry using standard forms; they are enthusiastic about our using

routinely collected health data for research. The study is powered to detect a

10% difference in primary outcomes between intervention and control groups

after adjusting for clustering. Field teams will be visiting clinics to extract the

relevant data (February–May 2016). After an analysis period (June–September

2016), we will write up and submit the results of the clinic-level trial by the end

of 2016.

3.2 Village-level RCT

The village-level RCT will also provide data on health outcomes, including

diarrhoea and pneumonia. The main objective of the village-level RCT is

to assess the impact of the intervention, HAP and faecal contamination of

drinking water — the main exposures that the intervention aims to mitigate.

A sub-study is also designed to investigate possible biomarkers of enteric

and respiratory exposures and disease in an effort to develop more objective

criteria for assessing these health disorders and the interventions designed to

prevent them.

For the village-level RCT, we enrolled 1582 households with children <5 from

174 study villages, evenly distributed between intervention and control arms.

At baseline, we collected extensive information from study participants on

The study is among the

largest RCTs ever conducted in

environmental health

Leading causes of death in children under 5 in Rwanda are

ALRI (16%) &Diarrhoea (9%)

Devices are registered by smartphone and tallied to GPS co-ordinates of its location.

demographics, water sources and management practices, cooking fuels and

cooking practices. Diarrhoea is assessed based on 7- day self-reports; ALRI

is assessed using World Health Organization and Integrated Management

of Child Illness (IMCI) criteria for pneumonia case identification in resource-

limited settings. This includes severity indices that incorporate cough, difficulty

breathing and rapid respiration (Puumalainen et al., 2008). The village-level

RCT is powered to detect a 25% difference in diarrhoea or pneumonia.

A sub-sample of 2 households in each study village was randomly selected

to undergo extended health and exposure evaluation. This includes an

extensive panel of physiologic measurements to assess blood pressure,

carboxyhemoglobin (COHb) concentrations (through pulse oximetry and

exhaled CO), O2 saturation (SpO2) and levels of various biomarkers of HAP

exposure, enteric infection and ALRI. Blood pressure is assessed among

main cooks in these households using a blood pressure monitor with cuff.

Eligible adults for this sub-study consist of women at least 16 years of age

who are identified as the main cook for the household and children under-5

years-old who live in selected households. Personal level gravimetric PM2.5

exposures are obtained cumulatively over 48 hours from the main cook and

a child between 1.5 and 4 years using a wearable pump/filter that includes a

light sensor to assess time-specific location and compliance. This also allows

us to explore dose-response relationships and to contribute to the limited

knowledge on the relationship between exposure and disease.

Dried blood spot samples were obtained at baseline and the second follow up

round in order to assess the utility of various biomarkers and as indicators of

systemic inflammation, personal exposure to PM2.5, seroconversion to enteric

pathogens and specific mechanistic disease processes. Biomarkers offer the

potential for improving the consistency of diagnoses of these diseases and the

exposures from contaminated air and drinking water that contribute to their

high prevalence in low-income countries; in addition, they can help inform

and improve the reliability of standardized disease outcome classifications.

We anticipate assessing levels of various inflammatory biomarkers (including

interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-α) and

C-reactive protein (CRP) for the cookstove component; antibodies against

antigens for Giardia spp., Cryptosporidium spp., E. coli and other enteric

pathogens for our seroconverson study; and biomarkers reflecting intestinal

dysfunction and permeability to assess environmental enteropathy.

Each recipient has their photo taken and details recorded when they receive their equipment.

Pneumonia and diarrhoea are responsible for an estimated

6.9M deaths annually

3.3 Cellular Instrumentation Monitoring

Within the RCT, the study leverages cellular based remotely reporting sensors

on a sample of the stoves and water filters. The water filter sensor measures

the volume of water when a household adds water to the filter for treatment.

It records the time of this addition and also logs how much water is removed

for consumption, and when the household backwashes the filter to clean

it. The stove sensor monitors every time the stove is used, the combustion

temperature, and duration. This data is cross-correlated against household

surveys.

The use of sensors on water filters allowed us to examine objectively the

quantity of water being treated in the home and the consistency of filter

use. An intra-household evaluation of consistent use may suggest that some

households are not treating enough water to meet their daily needs, potentially

indicating non-exclusive use of the filter. This has potential implications for

health and environmental impacts and may be considered in further behavior

change messaging and impact evaluations. Likewise, any inconsistent use of the

cookstoves may be indicative of stove-stacking behavior. As behavior change

efforts are modified and expanded, the instrumentation may be an effective

tool for evaluating the effectiveness of this messaging.

Building on this study, we are presently conducting a randomized controlled

trial to assess the behavioral impact of instrumented monitoring on household

use of water filters and cookstoves among two groups: 1) Households blinded

to (hidden) sensors installed on their water filters (Blinded Arm); and 2)

Households informed about visible sensors mounted on water filters (Open

Arm). We are using an equivalence trial design, with the null hypothesis that

product usage will be equivalent between the Open and Blinded arms. Overall

equivalent usage rates would suggest negligible reactivity to instrumented

monitoring in terms of product adoption and frequency of use. Examining

the change in usage rate during monitoring periods would yield insight to the

extent on which reactivity to sensors diminishes over time.

3.4 Investigators and Ethics

The study is a collaboration among the London School of Hygiene & Tropical

Medicine (LSHTM), Emory University, Portland State University (PSU), the

University of Rwanda School of Public Health (RSPH), Oregon Health Sciences

University (OHSU) and the Rwanda Ministry of Health (MoH). The study is led

RWANDA

D.R.CONGO

Lake Kivu

UGANDA

TANZANIA

BURUNDI

Rubavu

Karongi

Risizi-Nyamasheke

KIGALI

Gicumbi

Huye-Gisagara

Muhanga

LEGEND

PHASE 2

PHASE 3

CONTROL SECTORS

Kibungo

SECTORS IN RWANDA SHOWING CONTROL AREAS, PHASE 2, AND PHASE 3

by Thomas Clasen, JD, PhD, jointly appointed as Professor of Environmental

Health at Emory and Reader in Water, Sanitation and Health at LSHTM. Dr.

Clasen served as principal investigator of randomized, controlled trials and

other field studies in more than 15 countries in Asia, Africa and Latin America.

Co-investigators include Evan Thomas, PhD, PE, MPH (PSU); Ghislaine Rosa,

PhD, MSc (LSHTM); Jeannine Condo, PhD (RSPH); Corey Nagel, PhD, RN

(OHSU); and PhD students (Miles Kirby, LSHTM; Christina Barstow, Colorado;

and Laura Zambrano, Emory).

The full study (including clinic-level and village-level RCTs) has been approved

by the Rwanda National Ethics Committee, the London School of Hygiene &

Tropical Medicine Ethics Committee, and the Emory University Institutional

Review Board. The study has also been registered on ClinicalTrials.gov

(NCT02239250).

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