Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01660659 |
| Other study ID # |
SCC 1284 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 2012 |
| Est. completion date |
August 2015 |
Study information
| Verified date |
May 2018 |
| Source |
London School of Hygiene and Tropical Medicine |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Personal exposure to Indoor Air Pollution (IAP) is a known risk factor of severe pneumonia,
which is the number one killer of children under five in developing countries. The main
source of IAP in developing countries is cooking fires, with an estimated 3 billion people
still reliant on biomass stoves for their daily cooking. This study will test the
effectiveness of an intervention aimed to reduce IAP, as well as help to quantify the
relationship between exposure (IAP) and infection (pneumococcal carriage).
In Phase I (adjunct pilot study L2010.99), 3 fuels and 5 stoves were tested to measure
harmful pollutant emissions. The preliminary results showed that the largest difference was
found in the fuels (briquettes cleaner than wood), with a smaller difference found between a
couple of the improved stoves and the traditional 3-stone. Re-testing of selected stove/fuel
combinations to confirm findings has just been completed. Phase II (this proposal) will test
the biomass briquettes in a randomized clinical trial to measure actual IAP reductions in
households. A proof of concept pneumococcal survey will also be conducted as a secondary
study to see whether reduced exposure to IAP affects pneumococcal carriage in babies and
mothers
Description:
Acute respiratory infections (ARI), specifically Severe Pneumonia, are the leading cause of
death in children under 5 years of age. Of the nearly 10 million children under 5 who die
each year, 1.9 million die from ARI, almost all of which occur in developing countries [1,
2]. Over the years, various studies have identified many risk factors associated with ARI,
including malnutrition, zinc deficiency, indoor air pollution (IAP) from solid fuels and
tobacco. Proven efficacious interventions have been developed and studied to address risk
factors related to nutrition and zinc deficiency but still little is known about IAP and
proven effective interventions. Furthermore, little is known about the quantifiable
relationship between IAP exposure and disease, specifically ARI.
IAP from cooking with biomass is one of the top ten global health risks [3]. 1.6 million
people are estimated to die every year from IAP exposure, of which half of them are children
under 5 years of age [4]. In developing countries, IAP is estimated to account for 3.7% of
the total burden of disease, making it the fourth most serious health risk factor after
malnutrition, STDs, and inadequate water and sanitation [5]. A recent meta-analysis found
that children under 5 years old living in households using biomass fuels had a 78% greater
chance of contracting pneumonia than did children in households with cleaner-burning fuels
[6]. In Africa, 94% of the rural population and 73% of the urban population use solid fuels
as their primary source of energy [7]. Not only does IAP disproportionally affect the poor,
but it also affects women and children who spend more time near the cooking fires and are
therefore are most exposed.
Because of the difficulty in measuring exposure, most observational studies use proxy
measures. These proxies include the type of fuel used, amount of time spent near the cooking
fires, or whether the child is carried on the mother's back during cooking. But because
variations in personal exposure in most countries depend on a variety of factors (e.g. fuel,
stove, housing, behavioral), proxy indicators are an insufficient method to effectively
capture variations in exposure [8]. This affects the understanding and knowledge of the
potential health gains that might result from reducing exposure by varying amounts.
Determining this exposure-disease relationship is crucial to understanding the possible
impacts that interventions may have on improving health [9]. Unfortunately, the amount of
research being done on pollutant exposure from IAP is negligible compared to the huge disease
burden associated with this exposure [10]. A lot more research needs to be conducted to help
the lives of the 3 billion affected from these harmful pollutants.
Interventional Research Interventional research has focused on developing more efficient
biomass stoves as an approach to reduce IAP, yet few studies have looked into alternative
biomass fuels. Though improved stoves have shown to reduce pollutant emissions in controlled
settings, it remains difficult to measure the true effectiveness of this intervention, i.e.
whether these stoves are actually reducing pollutants in local kitchens. The Water Boiling
Test (WBT) and Controlled Cooking Tests (CCT), both of which are conducted in controlled
environments, are based on the assumption that performing a simple cooking task produces
estimates that can be used when evaluating technology for developing populations [11].
However, because of the numerous behavioral and outside variables that can alter the
efficiency of a stove, these tests do not illustrate the true picture of how the technology
will perform among the population [12]. The Kitchen Performance Test (KPT) has been designed
to measure the effectiveness though because of its difficulties in implementation, it is
often not used to measure stove performance. Furthermore, there have been varying results in
the field effectiveness of reducing IAP with improved stoves [9]. Given the wide variability
in stoves and settings, it remains difficult to know what levels of IAP exposure reductions
can be expected.
Because of the uncertainties and challenges of reducing IAP with improved stoves, other
interventions to reduce pollutant levels need to be explored, such as the use of alternative
biomass fuel in lieu of wood. A study in 2003 in rural Kenya looked at modelling potential
reductions on disease following interventions including fuel, stove type and cooking
location. This study showed that the largest reduction was from switching fuels and not
stoves [3]. There are a handful of studies throughout developing countries that are currently
looking at using crop waste as an alternative fuel. But because crop waste varies greatly
with locality, separate testing needs be done on these different crop wastes and their
transformation into cooking fuel. In The Gambia and most of West and Central Africa,
groundnuts are a major cash crop and their shells are available in abundance. Recently, two
separate factories have been established in The Gambia to process these dried groundnut
shells into biomass briquettes, which will then be used as cooking fuel. During Phase I of
this study, the investigators have tested (and are currently retesting) the two available
biomass briquettes made from groundnut shells. Both the WBT and CCT are being conducted to
evaluate the performance of these fuels (in comparison to wood and charcoal) when used with
different stoves, as well as IAP emissions. These tests were conducted in accordance with the
protocol developed for the Shell Foundation and Household Energy Health Program [13, 14]. The
investigators also concurrently measured PM2.5 concentrations two ways: continuous PM2.5
concentrations using light-scattering, TSI 8520 DustTrak monitors and integrated PM2.5
concentrations using gravimetric Casella pumps, cyclones, and Teflon filters. CO
concentrations were also measured alongside the CCT using Drager CO 50/a-D Diffusion Tubes.
The Investigators preliminary analysis shows that the briquettes do burn much cleaner than
wood when used with each of the tested stoves. The investigators are currently retesting the
briquettes with the different stoves to assure the investigators have the cleanest stove/fuel
combination for Phase II.
For Phase II (this proposal), the investigators will test the effectiveness of the biomass
briquettes in the communities. It is possible the investigators will also use an improved
stove with the briquettes, though this decision will not be made until the final analysis is
complete in December/January. However, based on the preliminary analysis, the investigators
are leaning more towards briquettes with the traditional 3-stone. For simplicity sake,
briquettes are mentioned as the intervention throughout this document. Though RCTs usually
measure the efficacy of an intervention, this study is slightly different in that the
efficiency and efficacy have already been conducted in Phase I. This study will enable the
investigators to evaluate the true reduction of IAP emissions in the study population, as
well as the cost effectiveness of using briquettes compared to wood or charcoal. From the
preliminary research, the investigators found that the briquettes performed very similarly to
wood, and therefore do not anticipate difficulties in adopting the use of briquettes.
Using pneumococcal carriage as a proxy measure for a health outcome Pneumonia accounts for
~30% of deaths of children under the age of 5 in developing countries, most resulting from
Streptococcus pneumoniae (pneumococcus). Pneumococci generally colonizes the nasopharynx
within the first months of life, with carriage rates in children in developing countries 2-3
times higher than those found in children from developed countries[15, 16]. In one study in
The Gambia, it was found that pneumococcal carriage was greater than 80% during the third
month of life [17]. In another study in Bangladesh, it was found that 50% of the children had
been colonized by pneumococci at least once by the age of 8 weeks [18]. Though pneumococcal
carriage is present in many healthy people, it is an identifiable risk for disease,
predominantly affecting the young in developing countries.
Nasopharyngeal colonization is a necessary phase before infection with S pneumoniae can occur
[19]. Therefore, preventing colonization from ever happening can be an important measure to
preventing S pneumoniae. As IAP exposure is one major risk factor to developing ARI,
understanding how IAP exposure can affect the risk of infection for pneumococcal carriers can
help us better understand the quantitative relationship between IAP exposure and disease
(severe pneumonia). There have been previous studies looking at the impact tobacco smoke has
on carriage, but to date, there has yet to be any research done looking at carriage and IAP
exposure. This study may be instrumental in helping understand this complex exposure-disease
relationship. This component of the study is a Proof-of-Concept study, and is therefore
designed to illustrate the potential relationship between IAP exposure and ARI. If using
pneumococcal carriage as a proxy does show to be an effective tool in helping to quantify the
this relationship, it has the potential to lay the foundation for further research looking at
IAP and its affect on pneumococcal carriage.
