Feasibility intervention trial of two types of improved cookstoves in three resource-limited settings: study protocol for a randomized controlled trial
Feasibility intervention trial of two types of improved cookstoves in three resource-limited settings: study protocol for a randomized controlled trial
Elizabeth Klasen 1
J Jaime Miranda 0
Subarna Khatry 2 6
Diana Menya 5
Robert H Gilman 4 6
James M Tielsch 6
Caitlin Kennedy 6
Robert Dreibelbis 6
Neha Naithani 6
Sylvester Kimaiyo 5
Marilu Chiang 4
E Jane Carter 3
Charles B Sherman 3
Patrick N Breysse 7
William Checkley 0 1 6
COCINAS Trial Working Group
0 CRONICAS Center of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia , Lima , Peru
1 Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University , 1800 Orleans Ave, Suite 9121, Baltimore, MD 21205 , USA
2 Nepal Nutrition Intervention Project Sarlahi , Kathmandu , Nepal
3 The Warren Alpert Medical School, Brown University , Providence, RI , USA
4 Biomedical Research Unit, Asociacion Benefica PRISMA , Lima , Peru
5 School of Public Health, Moi University , Eldoret , Kenya
6 Department of International Health, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, MD , USA
7 Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University , Baltimore, MD , USA
Background: Exposure to biomass fuel smoke is one of the leading risk factors for disease burden worldwide. International campaigns are currently promoting the widespread adoption of improved cookstoves in resource-limited settings, yet little is known about the cultural and social barriers to successful improved cookstove adoption and how these barriers affect environmental exposures and health outcomes. Design: We plan to conduct a one-year crossover, feasibility intervention trial in three resource-limited settings (Kenya, Nepal and Peru). We will enroll 40 to 46 female primary cooks aged 20 to 49 years in each site (total 120 to 138). Methods: At baseline, we will collect information on sociodemographic characteristics and cooking practices, and measure respiratory health and blood pressure for all participating women. An initial observational period of four months while households use their traditional, open-fire design cookstoves will take place prior to randomization. All participants will then be randomized to receive one of two types of improved, ventilated cookstoves with a chimney: a commercially-constructed cookstove (Envirofit G3300/G3355) or a locally-constructed cookstove. After four months of observation, participants will crossover and receive the other improved cookstove design and be followed for another four months. During each of the three four-month study periods, we will collect monthly information on self-reported respiratory symptoms, cooking practices, compliance with cookstove use (intervention periods only), and measure peak expiratory flow, forced expiratory volume at 1 second, exhaled carbon monoxide and blood pressure. We will also measure pulmonary function testing in the women participants and 24-hour kitchen particulate matter and carbon monoxide levels at least once per period. Discussion: Findings from this study will help us better understand the behavioral, biological, and environmental changes that occur with a cookstove intervention. If this trial indicates that reducing indoor air pollution is feasible and effective in resource-limited settings like Peru, Kenya and Nepal, trials and programs to modify the open burning of biomass fuels by installation of low-cost ventilated cookstoves could significantly reduce the burden of illness and death worldwide. Trial registration: ClinicalTrials.gov NCT01686867
Improved cookstove; Ventilated cookstove; Behavior change; Adoption; Indoor air pollution; DLCO; Spirometry; Biomass fuel
Global burden of disease attributed to biomass fuel smoke
More than half of the world population burns solid fuels,
including wood, dung, crop waste, coal and charcoal,
indoors for cooking. Incomplete combustion of these
materials results in the production of hazardous
byproducts that directly affect health [
]. The World
Health Organization has identified indoor combustion
of biomass solid fuels as one of the leading risk factors
for disease burden worldwide. In 2010, more than 3.5
million deaths and 4.3% (108 million) of global
disabilityadjusted life years (DALYs) were attributed to biomass
fuel smoke . Biomass fuel smoke appears to affect all
household members adversely [
], women and children
tend to have the highest risk of exposure to high levels of
indoor air pollution due to their involvement in the
cooking process. In developing countries, biomass fuel
exposure has been associated with an increased risk of
respiratory infections including pneumonia [
], chronic obstructive pulmonary disease (COPD)
], cardiovascular events, low birth weight and
allcause mortality in both adults and children [
Biomass fuel exposure as a risk factor for chronic respiratory disease
COPD is one of the most important causes of morbidity
and mortality in people 40 years of age and older, and it
is a disease with a substantial and increasing
socioeconomic burden [
]. A large-scale, population-based
study conducted in five Colombian cities  found that
cooking for 10 years or more with a wood stove was an
independent risk factor for COPD after adjustment for
multiple confounders (odds ratio = 1.5, 95% CI 1.4, 2.4).
The burden of COPD deaths is also disproportionally
concentrated in low- and middle-income countries (LMIC),
which accounted for nearly 90% of global deaths from
COPD in 2001 [
]. In 2010, COPD ranked third in causes
of morbidity worldwide and was responsible for 2.9 million
] and 4.7% of global DALYs lost [
]. By 2020
it is projected that COPD will be the fourth leading
cause of DALYs lost in LMIC [
]. In China alone, for
example, COPD is expected to kill 65 million people
between 2003 and 2033 [
], and this number is
expected to increase with an aging population [
Approximately 50% of deaths from COPD in LMICs are
thought to be attributable to the open burning of
biomass fuels, and it is estimated that 75% of these deaths
occur in women .
Respiratory outcomes that may change acutely after exposure to biomass fuel smoke
Studies of the natural history of COPD usually require
large numbers of patients and long periods of follow up
to detect differences between interventions on incident
rates of COPD. In studies of shorter duration, the forced
expiratory volume at one second (FEV1) and the rate of
decline in FEV1 are the most widely used outcome
measurements in short observational studies and clinical
trials of COPD [
]. FEV1 is central to the definition of
COPD and classification of its severity [
longitudinal studies that focus only on the rate of FEV1
decline in response to an intervention may also require
several years to manifest or detect in a population-based
study. Another respiratory outcome that may change
more acutely after the installation of an improved
cookstove is peak expiratory flow (PEF). PEF is defined as the
highest flow achieved at the mouth during a forced vital
capacity maneuver [
]. PEF can be easily measured with
a spirometer or peak-flow meter and is commonly used
in environmental epidemiology studies to monitor acute
changes in lung function after occupational or
toxicological exposures [
]. Another measure that would
be expected to change rapidly with successful
implementation of an improved cookstove is carboxyhemoglobin
], which can be easily measured with non-invasive
techniques. A direct measure of carbon monoxide (CO)
exposure is exhaled CO measured in parts per million.
Exhaled CO levels rise and fall dependent on the
participant’s exposure to CO in the preceding 2 to 3 days and
therefore can accurately classify present exposure levels.
An important measure of lung function is diffusing
capacity of the lung for CO (DLCO). Measurement of
the DLCO provides information on pulmonary gas
transfer. Abnormalities in diffusing capacity of the lung
are probably one of the earliest indications of
emphysematous changes due to cigarette smoke or biomass fuel
exposure, and a significant decline in DLCO may even
precede the development of obstruction. However, there
is limited work on early changes in DLCO in response
to biomass fuel exposure. A challenge in measuring
DLCO in field studies has been the portability of testing
equipment and the availability of gas mixture; however,
new developments in technology have made this
equipment more portable and accessible. The current study
will provide us with an opportunity to pioneer the
measurement of DLCO in field studies, understand the
effects of chronic exposure to biomass fuels on DLCO
variability, and to determine if there are changes in DLCO
after intervention with an improved, ventilated cookstove.
Previous research on improved, ventilated cookstoves
Improved, ventilated cookstoves have been introduced
as a potential method to considerably reduce exposure
to indoor biomass fuel smoke [
]. However, in field
trials where reductions in environmental emissions were
achieved with improved cookstoves, a concomitant effect
on health outcomes has not always been evident. For
example, a large, randomized field trial of improved
cookstoves in Guatemala was unable to measure an
important reduction in physician-diagnosed childhood
pneumonia despite a reduction of 50% in personal
environmental emissions after intervention with an
improved chimney stove [
]. The authors attributed a
lack of an effect due to an insufficient exposure
reduction; however, they did not expand on reasons why
their intervention failed to achieve important
reductions in environmental emissions. Similar reductions in
indoor air pollution of 40 to 60% with improved
cookstove interventions have been reported in Peru, China,
and India [
Little is known about how the determinants of
improved cookstove adoption and sustained use, the role of
individual perceptions of improved cookstoves as they
are shaped and the perceived benefits and limitations of
specific cookstove designs affect environmental
exposures and health outcomes. The difficulty of improved
cookstove interventions is in eliciting a two-fold
behavioral change by the user to cease in the use of the
traditional stove and to uptake the new technology [
Mixed-methods approaches are thus needed to
understand the behavioral, cultural and social barriers to
successful improved cookstove adoption and for accurately
determining the potential of improved, ventilated
cookstoves as effective methods for removing biomass fuel
smoke and removing the burden of chronic respiratory
disease in LMICs [
]. We aim to fill this gap in
knowledge by conducting a comprehensive study that
encompasses evaluation of environmental, respiratory
and cardiovascular health outcomes, and behavioral
changes before and after an intervention with improved
cookstoves with a chimney vent to the exterior, and
analyze the influences on the primary cookstove user
that determine her preferences for specific stove designs,
motivators and barriers to adoption, and contextual data
on the key behaviors associated with cooking.
This study is a multi-country, feasibility intervention
trial of improved, ventilated cookstoves to inform a
future, large-scale field trial. We aim to characterize
environmental, health and respiratory outcomes in three
diverse resource-limited settings (Kenya, Nepal and
Peru) with the goal of providing a more robust
understanding of the improved cookstove adoption process
and factors related to sustained use of improved,
ventilated cookstoves. We will install two different types of
improved cookstoves with a chimney, in rural
households where biomass fuels are used almost exclusively
for cooking, and evaluate the intervention based on the
following specific aims:
1. Compare particulate matter (PM) and CO
concentrations between traditional cookstoves
(before intervention) and two types of improved
cookstoves with a chimney (after intervention).
2. Compare respiratory outcomes (spirometry, PEF,
exhaled CO and DLCO) in women aged 20 to 49
years between traditional cookstoves (before
intervention) and the improved cookstoves with a
chimney (after intervention).
3. Assess behaviors, preferences and attitudes that
shape improved cookstove adoption and
intervention compliance among users of three types
of cookstoves; evaluate the reasons for their
preferred choice of cookstove; and, assess the
potential for sustained maintenance and use of the
A secondary, health outcome aim is to compare blood
pressure in women aged 20 to 49 years between
traditional cookstoves (before intervention) and the
improved cookstoves with a chimney (after intervention).
Our study design will be a randomized crossover
intervention trial in which all participants will first have a run-in
observational period of four months with their traditional
cookstove prior to randomization into two intervention
arms (Figure 1). At baseline, we will obtain
sociodemographic information for each household, respiratory
outcomes and other health data for the participating
women. Qualitative methods, such as interviews and
direct observations, and quantitative questionnaires will be
used during the observational period to collect data on
fuel use, the cooking process, and the participant’s current
perception of their traditional cookstove. One of the
intervention arms will first have the commercially constructed,
ventilated cookstove installed in their kitchen (Figure 2).
They will then be followed for four months. At crossover,
we will install a locally constructed, ventilated cookstove
and follow the participants for another four months. The
other intervention arm will first receive the locally
constructed cookstove at the beginning of the first
fourmonth intervention period followed by installation of the
commercially constructed improved, ventilated cookstove
for the second four-month intervention period. The
materials and method of construction of the locally constructed
cookstove will vary by site (Figures 3, 4, 5).
During each of the two four-month intervention periods,
we will request that the woman participant exclusively uses
the improved, ventilated cookstove installed for that period.
We will assess the intervention adoption process,
compliance with cookstove use, respiratory health and blood
pressure monthly. Environmental measures will be taken at
least once at baseline and during each intervention period.
A = Traditional, open-fire cookstove
B = Locally constructed, improved cookstove
C = Commercially constructed, improved cookstove (Envirofit G-3300/3355)
1 – 4 months
5 – 8 months
9 – 12 months
PEF/FEV1, exhaled CO and blood pressure (grey and black); behavioral and compliance assessments (black)
Spirometry, environmental and behavioral assessments
Spirometry will be measured once during the baseline
period and at the end of the intervention periods. DLCO
will be measured once during the baseline period and at
the end of the intervention periods in Peru only.
Participants will participate in in-depth interviews every period
discussing their opinions of the current stove they are using
and previous stoves used. The cooking process will be
directly observed at least once per period to record
changes in cooking-related behaviors and practices. At
the end of the second four-month period, we will
crossover and install the second type of improved, ventilated
cookstove and follow all participants for another four
months. Following each four-month period a focus group
will be conducted with study staff. The study will require
12 consecutive months to complete at each site.
The trial will be implemented at the United States National
Heart, Lung and Blood Institutes and UnitedHealth Group
Centers of Excellence in Chronic Diseases in Kenya
(ASANTE Center of Excellence) and Peru (CRONICAS Center
of Excellence) and at the Nepal Nutrition Intervention
Project, Sarlahi (NNIPS) in Nepal. Partners include Johns
Hopkins University in Baltimore, USA and Brown University in
Providence, USA. All three field sites have local offices and
staff that provide sufficient and culturally sensitive
infrastructure for recruitment, intervention, data collection and
data entry for the implementation of this project. This
study was approved by the Institutional Review Boards of
Universidad Peruana Cayetano Heredia (Lima, Peru), Johns
Hopkins Bloomberg School of Public Health (Baltimore,
USA), A.B. PRISMA (Lima, Peru), Moi University (Eldoret,
Figure 5 Locally constructed, improved cookstove installed in Kenya.
Kenya), Institute of Medicine at Tribhuvan University
(Kathmandu, Nepal) and Lifespan/The Miriam Hospital
Study setting and populations
The study will take place in three rural, resource-limited
settings: the Ndanai sub-location of the Uasin Gishu
district in western Kenya, the southern district of Sarlahi in
Nepal, and the Vinchos district of Ayacucho in the
foothills of the Andes in Peru. Households in the three study
settings use biomass fuels almost exclusively as the
primary source of energy for cooking and heating. The site in
Kenya is located in a rural setting in Rift Valley, Kenya at
approximately 2,200 meters above sea level. Wood and
crop residues are the main sources of biomass fuel for this
population. The site in Nepal is located in the low-lying,
southern plains of the Sarlahi District (the Terai) at 300
meters above sea level. The study area encompasses 30
Village Development Committees with a total population
of approximately 190,000 inhabitants. More than 95% of
the population under study burn biomass fuels and
primary sources of biomass fuel include wood, dung and
crop waste. Its culture and geography are similar to other
areas of southern Nepal, northern India and Pakistan, and
western Bangladesh. The site in Ayacucho, Peru is located
in the Andes at altitudes ranging between 3,000 and 4,000
meters above sea level. Ayacucho is among the poorest
departments in Peru, with an extreme poverty rate of 45%,
an illiteracy rate of 43% among women. Among the poor
populations, 75% live in adobe huts and 91% burn biomass
fuels. Wood and dung make up the majority of the
biomass fuel burned by the population.
Each site will enroll 40 to 46 women for a total study
population of 120 to 138 participants. To be eligible for
enrollment, the woman must meet the following criteria:
be between 20 and 49 years of age; be the main household
cook; primarily use a traditional, open-fire cookstove
indoors in a structure with at least three walls and a roof;
be willing to have two types of improved cookstoves
installed and agree to use them during the intervention
period to which they are assigned; have household walls
of mud, brick, cement, or wood; be a full-time resident
of the intervention community capable of providing
informed consent; and participate in all study procedures.
The two types of improved, ventilated cookstove
incorporate the following characteristics: at least two burner
openings; a cleanable entrance and combustion chamber for
biomass fuel; a flue designed to draw air into the fire box
and pass it out through a chimney; a chimney, vented to
the exterior, of adequate height to create a draft; an exterior
port designed to prevent the backflow of smoke and an
access port for the chimney that permits cleaning. There are
multiple commercially constructed and locally constructed
models available with the above specifications. To assess
cookstove functionality over time and the multifaceted
determinants of use involved with an improved, ventilated
cookstove intervention we will install and compare both a
commercially-available and a locally-constructed cookstove
in each enrolled household.
We selected the Envirofit G-3300/3355 (www.envirofit.org)
for installation in every site and a site-specific
locallyconstructed improved, ventilated cookstove for use in
the trial. We piloted multiple locally-constructed
improved, ventilated cookstoves. The goal of this pilot
study was to compare ability to reduce indoor air
pollution, the reliability between cookstoves of the same
type, the functionality over time, preferences and
cultural compatibility, and cost.
The installation and explanation of the cookstoves will
be important for their acceptance and sustained
maintenance and use. During installation, complete
household assistance and observation during the process will
be encouraged. Education on the intervention will be
mandatory for participating women, although all family
members will be encouraged to attend.
Since this study was designed as a feasibility trial to
inform a future, large-scale field trial, we did not calculate
a sample size to demonstrate an intervention effect for
our primary outcomes. However, the study sample
should provide a sufficient indication of the relationship
between decreased indoor biomass fuel smoke exposure
and improved respiratory health outcomes across and
among interventions with improved cookstoves. In
addition, the sample size allows for the combination of
qualitative and quantitative data collection and monthly
respiratory and compliance follow-up.
We will collect the following sociodemographic data at
enrollment: household demographics, including the age
and sex of all persons; household construction including
the materials used for the walls, roof, and floor, number of
rooms and floors; household socioeconomic status;
information on cooking practices and types of fuels used with
traditional cookstoves; and exposure to tobacco smoke
(number of persons smoking in the home and amount).
We will also collect baseline data on respiratory
outcomes using a modified version of the study questionnaire
from the Burden of Obstructive Lung Disease (BOLD)
]. The baseline data will also include
anthropometric measurements (height and weight), total hemoglobin
(g/dL) measured non-invasively by fingertip arterial blood
sensor (Masimo Pronto or Pronto 7, Irvine, CA, USA), a
measurement of exhaled CO and blood pressure. We will
include a detailed questionnaire about personal history of
smoking and second-hand smoke.
In-depth interviews will begin during the traditional
cookstove observation period and continue through both
intervention periods. Their purpose is to collect
information on how participants view their current
cookstove, perceptions of indoor air quality, and the social
and cultural context in which cooking and stove
preference and use is embedded. All interviews will be led by
the participant with the interviewer guiding the direction
of the interview as they probe for relevant information
based on an interview guide. Interviews will occur at
least once per period in a setting of the respondent’s
choice, generally in the household. Interviews will be
conducted in the local language and are expected to last
between fifteen minutes and one hour.
Semi-structured interviews will be carried out monthly
throughout the intervention periods to closely follow the
adoption process as participants transition from one type
of improved, ventilated cookstove to the other, and
understand related opinions and behaviors. Questions will be
less open-ended than those in the in-depth interviews and
responses are expected to be shorter and more concise.
Structured observations will be used to determine typical
cooking times and lengths, type of foods cooked and
individuals present during stove use. During the
observation, a staff member will sit in an unobtrusive place in
the household in sight of the main cooking practices and
observe use and handling of existing stoves, types of
food prepared, and how cookstoves affect food
preparation and dynamics within the household, while taking
notes. Observations will be conducted either during
morning or evening cooking practices and are expected
to last from meal preparation to cooking completion.
Staff members will be instructed not to interact with the
participants except as necessary for politeness. All
household members present at the time of the
observation will be asked if they are comfortable being present
during the observation period, and if any household
member does not agree to observation, cooking practices
in that household will not be observed at that time.
Focus groups will be conducted with data collection
staff. Their perspectives and experiences with both
traditional and improved cookstoves in the course of trial
implementation will complement the perspectives of
participants gained from interviews. Focus groups will
occur following each study period of four months and
will be limited to individuals of the same general rank
within the project to avoid having supervisors and their
staff in the same discussion. Focus group participants
will be informed that their participation in the focus
group will not affect their employment with the study,
and they are free to decline to answer any question they
feel uncomfortable answering.
Longitudinal behavioral and compliance data
We will collect both quantitative and qualitative behavioral
data and cookstove use compliance data monthly during
the study periods. Compliance with improved cookstove
use will be assessed by asking women how many total
meals were cooked per day in the household in the
preceding two weeks and how many were cooked using the new
cookstove. We will ask how often a cookstove was used for
a purpose other than cooking, what proportion of those
times the cookstove was used, and what types of fuel
sources were used. We will also determine if the
intervention cookstove was not used during its corresponding
intervention period and the reasons for the decision. Any
modifications to the new cookstoves made by the families
and any damage or breakdown of the cookstove will also
be recorded during these monthly visits. We will also ask
about length of cooking time to better understand whether
the new stoves alter cooking time, which could be
important for understanding compliance and acceptance.
In addition to the structured survey data on compliance
and practices, we will use semi-structured interviewing
techniques to assess individual preference and attitudes
toward cookstoves and ways in which participants have
adapted existing cooking practices and stove-use practices.
Longitudinal qualitative interviews will provide an
opportunity to assess how individual attitudes towards
cookstoves, and ultimately acceptance of the new technology,
are shaped over time and with repeated use. We will also
assess changes in cooking practices over time. At the end
of the trial, we will ask participants to indicate their
preferred cookstove and to complete a final in-depth
interview regarding individual preference, experiences using all
three cookstove varieties, and the perceived benefits and
drawbacks of each stove.
To assess indoor air quality, we will measure 24-hour
indoor air PM and CO concentrations at least once during
the baseline period and again during each intervention
period. Before the start of every study period, all
environmental sampling equipment will undergo quality
control checks according to manufacturer instructions to
ensure quality performance across all machines. We plan
to measure particulate matter with the pDR-1000
(Thermo Scientific, Franklin, MA, USA) passive sampler
for a 24-hour period. This device incorporates a pulsed,
high output, near-infrared light-emitting diode source.
The intensity of the light scattered over the forward angle
by particles passing through the sensing chamber is
linearly proportional to airborne PM concentration. The
pDR-1000 detects particles of 0.3 to 2.0 μm in size more
efficiently than 2.0 to 10.0 μm [
]; however, there is a
high level of agreement between PM determined by the
pDR-1000 and gravimetric measurements of PM2.5
]. Therefore, PM measured with the pDR-1000 is a
good approximation for PM2.5. Every machine will be
calibrated to zero-air before deployment in the field. We will
measure relative humidity (RH) using the HOBO Data
Logger (Onset Corp., Bourne, MA, USA) to adjust PM by
RH . We will carry out the measurements of ambient
CO in the same 24-hour period as the PM measurements
with the EasyLog USB CO Monitor (Lascar Electronics,
Eerie, PA, USA). We will place the environmental
measurement setup approximately 1.0 to 1.5 m above the floor
and <1.0 m away from the current cookstove.
We will measure height and weight once at baseline for
each individual using standard techniques [
following will be measured, beginning at baseline, monthly
throughout the trial:
PEF and FEV1: the Piko-1 (nSpire Health, Inc.,
Longmont, CO, USA) will electronically measure
PEF and FEV1. We will obtain at least two PEF
measurements within 70 L/minute and at least two
FEV1 measurements within 0.90 L.
Exhaled CO levels and carboxyhemoglobin (% COHb):
a Micro CO (Micro Direct, Inc., Lewiston, ME, USA)
will electronically measure exhaled CO (ppm) and %
COHb. Any exhaled CO measurement over 10 ppm
will be repeated up to three times until two
measurements are obtained within ± 2 ppm. The
average of the obtained measurements will be reported.
Pulse oximetry: arterial saturation of oxygen,
perfusion index and pulse will be measured by
fingertip sensor with a Masimo Rad 5v (Masimo,
Irvine, CA, USA).
Blood pressure: systolic and diastolic blood pressure
will be recorded with Omron Healthcare 10 Series
(Omron Healthcare, Inc., Lake Forest, IL, USA).
The device has an internal calibration check system.
We will measure the following respiratory outcomes
at least once at the mid-point of each four month
Spirometry: we will use a flow-based spirometer (EasyOne Pro, ndd Zurich, Switzerland) to measure
lung function. We will record forced vital capacity
(FVC), FEV1, FEV1/FVC, PEF and flow-volume
curves. We will obtain at least three acceptable and
reproducible spirometric maneuvers in accordance
with the joint European Respiratory Society and
American Thoracic Society guidelines [
]. A field
supervisor will review flow-volume curves with
technicians on a daily basis to evaluate for quality.
De-identified flow-volume curves will be transmitted
on a weekly basis to Baltimore for additional
over-read and grading.
DLCO: this measurement will only be conducted in
Peru. We plan to measure DLCO as it is feasible
using the EasyOne Pro (ndd, Zurich, Switzerland).
We will follow standard criteria from the American
Thoracic Society for the measurement of DLCO
], and adjust values of DLCO for altitude,
hemoglobin and COHb levels.
The system for data collection in the field will be
primarily paper based. For the social and behavioral
component, we will collect detailed field notes from each
household visit and audio-recorded interviews that will
be transcribed by local field staff and translated into
English. Data processing and storage will be centralized
at the Data Coordinating Center in Peru. Data will be
stored at a central server in the Data Coordinating
Center and will be shared with all collaborators.
We plan to perform a one-year, community-based
feasibility trial in which we will install two types of improved
cookstoves with a chimney, in 40 to 46 rural households
of women aged 20 to 49 years, in three resource-limited
settings. Improved cookstoves have been investigated as
a solution to prevent or reduce lung disease in low- and
middle-income countries, especially in women and
children. However, previous research on improved
cookstoves has focused on exposure, fuel consumption and
health outcomes. To date, limited data exists on the
social, economic, and behavioral influences on successful
cookstove integration measured by exposure reduction
and positive health outcomes. As preferences for specific
stove designs, attitudes towards using new technologies,
and contextual data on the behaviors associated with
cooking may also vary by cultural context, a better
understanding of how use is adapted over time, how
individual perceptions of improved cookstoves are shaped,
and perceived benefits and limitations of improved
cookstoves is needed [
]. If this trial demonstrates that
reducing indoor air pollution is feasible and potentially
effective in resource-poor settings like Peru, Kenya and
Nepal, programs designed to modify the open burning
of biomass fuels by installation of low-cost, ventilated
cookstoves could significantly reduce the burden of
COPD illness and death.
Our study has some potential shortcomings. First, the
overall number of participants enrolled in this trial is
small. As the trial was designed as a feasibility study
spanning three countries with a longitudinal qualitative
component, the number of participants able to be
enrolled was restricted. However, as designed, the study
participants will serve as their own controls and we will
be able to evaluate their experiences with a locally
constructed, ventilated cookstove and a commercially
constructed, ventilated cookstove. Second, we may incur
bias in self-reported symptoms after installation of the
intervention due to participant awareness of the health
benefits associated with improved cookstoves. Another
potential limitation of the study is not testing a
movement up the fuel ladder to a cleaner fuel, such as
liquidpropane gas, biogas or electric cookstoves. However, a
cleaner fuel is not an appropriate intervention for our
intended populations at this time, as the selected rural
populations do not have the supply system or financial
ability to sustain an intervention aimed at upward
movement on the fuel ladder. Cleaner fuels are the way of the
future but to address the burden now, we must focus on
appropriate methodologies that utilize currently available
energy sources [
Institutional Review Board approval has been secured
for all sites and the trial has been registered with www.
clinicaltrials.gov. Data collection has begun at all sites.
CO: Carbon monoxide; COHb: Carboxyhemoglobin; COPD: Chronic
obstructive pulmonary disease; DALY: Disability-adjusted life year;
DLCO: Diffusing capacity of the lung for carbon monoxide; FEV1: Forced
expiratory volume at one second; FVC: Forced vital capacity; LMIC: Low- and
middle-income countries; PEF: Peak expiratory flow; PM: Particulate matter;
RH: Relative humidity.
The authors declare that they have no competing interests.
WC, JM, SKh and DM conceived the original study design. EK, MC, RG and
WC were responsible for conduct of the study in Peru; NN, SKh and JT were
responsible for conduct of the study in Nepal; and DM, SKi, JC and CS were
responsible for conduct of the study in Kenya. PB provided expert guidance
in the design and conduct of the environmental exposure assessment.
CK and RD provided expert guidance in the design and conduct of social
behavioral assessment. EK and WC led the writing of the manuscript.
WC had ultimate oversight over the study design and conduct of this trial.
All authors contributed equally to the development of the study design, and
conduct, and the writing of the manuscript. All authors read and approved
the final manuscript.
Members of the COCINAS Trial Working Group: Angela Huaman (A.B. PRISMA),
Mariela Levano (A.B. PRISMA), Delia Haustein (A.B. PRISMA), Evelyn Rhodes (Johns
Hopkins University), Laura Grajeda (Johns Hopkins University), Stephanie Levy
(Johns Hopkins University), Steven LeClerq (Johns Hopkins University), Robert
Wise (Johns Hopkins University), Priscah Mosol (Moi University), Francis
Ogaro (Moi University), Cosmas Apaka (Moi University), Joyce Baliddawa
The authors would like to thank Jerry Masiello (ndd), Emery Parsons (ndd),
Martin Segnel (ndd), Lorenz Sourlier (ndd), Phabiola Herrera (Johns Hopkins
University), Karina Romero (A.B. PRISMA), Juan Gabriel Espinoza (A.B. PRISMA),
and Grover Gomez (A.B. PRISMA). This study was supported by federal funds
of the National Heart, Lung, and Blood Institute, United States National
Institutes of Health, Department of Health and Human Services under
contract number HHSN268200900033C. Publication of this article was funded
in part by the Open Access Promotion Fund of the Johns Hopkins University
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