109 research outputs found
The Effects of Electronic and Photonic Coupling on the Performance of a Photothermionic-Photovoltaic Hybrid Solar Device
This work presents a detailed analysis of the photothermionic-photovoltaic
hybrid solar device. The electrons in this hybrid device gain energy from both
the solar photons and thermophotons generated within the device, and hence the
device has the potential to offer a voltage boost compared to individual
photothermionic or photovoltaic devices. We show that the gap size between the
photothermionic emitter and the photovoltaic collector crucially affects the
device performance due to the strong dependence of the electronic and photonic
coupling strengths on this gap size. We also investigate how the current
matching constraint between the thermionic and photovoltaic stages can affect
the hybrid solar device performance by studying different hybrid device
configurations. Moreover, the hybrid devices are compared with the single
photothermionic solar device with a metallic collector. Interestingly, we
observe that the addition of a photovoltaic stage meant to enable the hybrid
device to capture the entire terrestrial solar spectrum does not necessarily
lead to higher overall conversion efficiency.Comment: 38 Pages, 11 Figure
Feasibility of introducing pulse oximetry for identifying hypoxaemia among children with pneumonia in paediatric outpatient settings in Bangladesh: Generating evidence and synthesising knowledge for influencing policy, programme planning and practice
BACKGROUND:
Pneumonia is the leading cause of childhood mortality, accounting for 16% of all
under-5 deaths globally. Hypoxaemia is common among children with pneumonia
and one of the strongest predictors of mortality. Since 2014, the World Health
Organization has recommended introducing pulse oximetry for hypoxaemia
identification and pneumonia classification in the Integrated Management of
Childhood Illness (IMCI) services, which is a global strategy developed explicitly for
outpatient management of common childhood illnesses, including pneumonia, in
low-resource and high-burden settings by minimally trained health care providers.
Unfortunately, there are few experiences of introducing pulse oximetry in paediatric
outpatient settings and integrating it with IMCI services by adopting a health system
strengthening approach.
Bangladesh is one of the South Asian countries with high burdens of childhood
pneumonia and hypoxaemia. Although Bangladesh has adopted the IMCI strategy
and scaled up it nationally, pulse oximetry is neither recommended nor routinely
used in IMCI services in Bangladesh. Successful introduction of a generic
recommendation, technology, or device, like pulse oximetry, in routine services,
demands an in-depth understanding of the problem and the context, followed by
context-specific adaptations, demonstrations, and feasibility assessments. Also, it
requires strategic and extensive engagement with policymakers and stakeholders to
promote country ownership and government leadership, which are prerequisites for
scalability and sustainability.
OBJECTIVES AND METHOD:
The overall goal of my PhD is to improve the management of childhood pneumonia
by introducing and integrating pulse oximetry in routine IMCI services in Bangladesh.
Furthermore, the aim is to support the Government of Bangladesh in taking an
evidence-based decision in this regard. Hence, I was engaged in a series of
discussions with the policymakers of the Ministry of Health and Family Welfare of
the Government of Bangladesh to understand their perspectives on the existing
evidence gaps and research priorities for making informed decisions regarding pulse
oximetry integration. Based on these consultations, I identified my PhD objectives.
RESULTS:
A. Estimating the burden of hypoxaemia among children with pneumonia:
I conducted a systematic review and meta-analysis by searching 11 bibliographic
databases and citation indices. I reported pooled prevalence of hypoxaemia
(SpO2<90%) by classification of clinical severity and by clinical settings by using the
random-effects meta-analysis models. I identified 2,825 unique records from the
databases, of which 57 studies met the eligibility criteria: 26 from Africa, 23 from
Asia, four from South America, and four from multiple continents. The prevalence
of hypoxaemia was 31% (95% CI, 26 to 36; 101,775 children) among all children
with WHO-defined pneumonia, 41% (95% CI, 33 to 49; 30,483 children) among
those with very severe or severe pneumonia, and 8% (95% CI, 3 to 16; 2,395
children) among those with non-severe pneumonia. The prevalence was much
higher in studies conducted in emergency and inpatient settings than those
conducted in outpatient settings. In 2019, we estimated that over 7 million children
(95% UR, 5 to 8 million) were admitted to the hospital with hypoxaemic pneumonia.
I also conducted a secondary analysis of data obtained from icddr,b-Dhaka Hospital,
a secondary level referral hospital located in Dhaka, Bangladesh. I included 2,646
children aged 2-59 months admitted with WHO-defined severe pneumonia during
2014-17. On admission, the prevalence of hypoxaemia among children hospitalised
with pneumonia was approximately 40% (95% CI, 38 to 42). Hypoxaemia was the
strongest predictor of mortality (AOR = 11.1; 95% CI, 7.3 to 16.9) and referral
(AOR = 5.9; 95% CI, 4.3 to 17.0) among other factors such as age, sex, history of fever
and cough or difficulty in breathing, and severe acute malnutrition. Among those
who survived, the median duration of hospital stay was 7 days (IQR, 4 to 11) in the
hypoxaemic group and 6 days (IQR, 4 to 9) in the non-hypoxaemic group, and the
difference was significant at p<0.001.
B. Understanding the context of managing children with pneumonia, including
hypoxaemia in Bangladesh:
I conducted a secondary analysis using data from the 2017-18 round of the
Bangladesh Demographic and Health Survey (BDHS), which adopts a nationally
representative sample of households. I included 456 deaths among children under 5 years of age in our analysis. Descriptive statistics were used to present the causes,
timing, and places of death with uncertainty ranges (UR). Pneumonia is the major
killer (19%, 95% CI, 15.3 to 22.7), accounting for approximately 24,268 (UR, 21,626
to 26,695) under-5 deaths per year. Among children aged 1-11 months, pneumonia
accounts for approximately 43% of deaths.
I further conducted a secondary analysis of the Bangladesh Health Facility Survey 2017, which was conducted with a nationally representative sample including all
administrative divisions and types of health facilities. More than 90% of the district
hospital and sub-district hospitals and three-fourths of primary level health centres
provide IMCI-based pneumonia management services. Pulse oximetry was
available in 27% of the district hospitals, 18% of the sub-district level hospitals and
none of the primary level health centres. Around 72% of the sub-district hospitals
had the availability of one of any of the four oxygen sources (oxygen concentrators,
filled oxygen cylinder with flowmeter, filled oxygen cylinder without flowmeter, and
oxygen distribution system), followed by district hospitals (66%). Almost none of the
primary level health centres had oxygen sources available on the day of the visit.
C. Assessing the feasibility of introducing pulse oximetry in routine IMCI
services:
Based on literature review and expert consultations, I developed a conceptual
framework, which guided the planning and implementation of a 4-step stakeholder
engagement process for introducing pulse oximetry in routine IMCI services in
Bangladesh. In the first step, a comprehensive desk review and key informant
interviews were conducted to identify stakeholder organisations and score them
based on their power and interest levels regarding IMCI implementation in
Bangladesh. In the second step, two national level, two district level and five sub-
district level sensitisation workshops were organised to orient all stakeholder
organisations having high power or high interest regarding the importance of using
pulse oximetry for pneumonia assessment and classification. In the third step,
national and district level high power-high interest stakeholder organisations were
involved in developing a joint action plan for introducing pulse oximetry in routine
IMCI services. In the fourth step, led by a formal working group under the leadership
of the Ministry of Health, we updated the National IMCI Implementation Package,
including all guidelines, training manuals, services registers and referral forms in
English and Bangla. Our engagement process contributed to the national decision
to introduce pulse oximetry in paediatric outpatient settings and update the
National IMCI Implementation Package demonstrating country ownership,
government leadership and multi-partner involvement, which are steppingstones
towards scalability and sustainability. However, our experience clearly delineates
that stakeholder engagement is a context-driven, time-consuming, resource-intensive, iterative, and mercurial process that demands meticulous planning,
prioritisation, inclusiveness, and adaptability.
Based on WHO’s global recommendation in 2014, the National IMCI Programme of
Bangladesh decided to introduce pulse oximetry in routine IMCI services in 2019 and
developed a short training package for IMCI service providers. They decided to test
the package in a relatively controlled setting for finalising the content and choice of
pulse oximetry device before the demonstration in routine outpatient settings and
subsequent scale-up. A cross-sectional study was conducted among children
admitted to a rural district hospital. We employed 11 nurses and seven paramedics
as assessors who received a one-day training on pulse oximetry. Each assessor
performed at least 30 pulse oximetry measurements on children with two types of
handheld devices. The assessors successfully established a stable SpO2 reading in
all attempts (n=1478) except one. The median time taken was 30 seconds (IQR, 22
to 42), and within 60 seconds, 92% of attempts were successful. The median time
was significantly (p<0.0001) higher among assessments conducted with a Lifebox
device (36 seconds, IQR, 25 to 50) than those with a Masimo device (27 seconds,
IQR, 20 to 35). Similarly, assessors aged >25 years are 4.8 (95% CI, 1.2 to 18.6) times
more likely to obtain a stable reading within 60 seconds. Regarding patient-related
factors, the odds of obtaining a stable SpO2 reading was 2.6 (95% CI, 1.6 to 4.2) times
higher among children aged 12-59 months than among children aged 2-11 months.
The National IMCI Programme of Bangladesh designed and developed a district
implementation model for introducing pulse oximetry in IMCI services through
stakeholder engagement and demonstrated the model in the Kushtia district by
adopting a health system strengthening approach. Between December 2020 and
June 2021, two assessment rounds were conducted based on WHO’s
implementation research framework and outcome variables in 12 facilities involving
22 IMCI service providers and 1860 children presenting with cough/difficulty in
breathing in the IMCI consultation rooms. WE OBSERVED THAT IMCI SERVICE PROVIDERS
PERFORMED PULSE OXIMETRY ON ALMOST ALL ELIGIBLE CHILDREN, OF WHICH 99% OF
ASSESSMENTS WERE SUCCESSFUL; 85% (95% CI, 83 TO 87) IN ONE ATTEMPT AND 69% (95%
CI, 67 TO 71) WITHIN ONE MINUTE. The adherence to standards of procedures related
to pulse oximetry was 92% (95% CI, 91 to 93), and agreement regarding identifying
hypoxaemia was 96% (95% CI, 95 to 97). The median performance time was 36
seconds (IQR, 20 to 75), which was longer among younger children (2-11 months: 44
seconds, IQR, 22 to 78; 12-59 months: 30 seconds, IQR 18 to 53, p<0.001) and among
those classified as pneumonia/severe pneumonia than as no pneumonia (41
seconds, IQR, 22 to 70; 32 seconds, IQR, 20 to 62, p<0.001). We observed
improvements in all indicators in the second round of assessments. Caregivers
showed positive attitudes towards using this novel technology for the assessment of
children.
CONCLUSION:
Based on context-specific experience generated through these studies, the
Government of Bangladesh decided to integrate pulse oximetry into routine IMCI
services throughout Bangladesh. Furthermore, the learnings synthesised through
these studies can also help convince the policymakers and managers of other LMICs
with similar burdens and contexts to introduce pulse oximetry in routine settings
providing outpatient-based paediatric services and contribute to achieving the target
of averting all preventable childhood pneumonia deaths by 2025
Towards a Business Intelligence Systems Development Methodology: Drawing on Decision Support and Executive Information Systems
Business Intelligence (BI) systems are important IT platforms providing decision support in many enterprises, but there is a lack of independent BI-specific systems development methodologies. Further, while BI has been acknowledged as a successor to Executive Information Systems (EIS), there is little empirical evidence underpinning this view. This paper presents a case study of a BI systems development project in a large Australian healthcare organisation to argue that the development challenges faced by BI systems developers are largely similar to the challenges addressed by EIS development methodologies, and that an EIS development methodology is a useful starting point for designing a development methodology specifically for BI systems
Impact of maternal and neonatal health initiatives on inequity in maternal health care utilization in Bangladesh
BackgroundDespite remarkable progress in maternal and child health, inequity persists in maternal care utilization in Bangladesh. Government of Bangladesh (GOB) with technical assistance from United Nation Population Fund (UNFPA), United Nation Children’s Fund (UNICEF) and World Health Organization (WHO) started implementing Maternal and Neonatal Health Initiatives in selected districts of Bangladesh (MNHIB) in 2007 with an aim to reduce inequity in healthcare utilization. This study examines the effect of MNHIB on inequity in maternal care utilization.MethodTwo surveys were carried out in four districts in Bangladesh- baseline in 2008 and end-line in 2013. The baseline survey collected data from 13,206 women giving birth in the preceding year and in end-line 7,177 women were interviewed. Inequity in maternal healthcare utilization was calculated pre and post-MNHIB using rich-to-poor ratio and concentration index.ResultsMean age of respondents were 23.9 and 24.6 years in 2008 and 2013 respectively. Utilization of pregnancy-related care increased for all socioeconomic strata between these two surveys. The concentration indices (CI) for various maternal health service utilization in 2013 were found to be lower than the indices in 2008. However, in comparison to contemporary BDHS data in nearby districts, MNHIB was successful in reducing inequity in receiving ANC from a trained provider (CI: 0.337 and 0.272), institutional delivery (CI: 0.435 in 2008 to 0.362 in 2013), and delivery by skilled personnel (CI: 0.396 and 0.370).ConclusionsOverall use of maternal health care services increased in post-MNHIB year compared to pre-MNHIB year and inequity in maternal service utilization declined for three indicators out of six considered in the paper. The reductions in CI values for select maternal care indicators imply that the program has been successful not only in improving utilization of maternal health services but also in lowering inequality of service utilization across socioeconomic groups. Maternal health programs, if properly designed and implemented, can improve access, partially overcoming the negative effects of socioeconomic disparities
HOW OFTEN IS LEFT MAIN OR LEFT ANTERIOR DESCENDING ARTERY THE CULPRIT VESSEL IN PATIENTS PRESENTING WITH NEW OR PRESUMED NEW LEFT BUNDLE BRANCH BLOCK AND SUSPECTED ACUTE CORONARY SYNDROME?
Determinants of caesarean section in Bangladesh: Cross-sectional analysis of Bangladesh demographic and health survey 2014 data
BACKGROUND:Caesarean section (CS) has been on the rise worldwide and Bangladesh is no exception. In Bangladesh, the CS rate, which includes both institutional and community-based deliveries, has increased from about 3% in 2000 to about 24% in 2014. This study examines the association of reported complications around delivery and socio-demographic, healthcare and spatial characteristics of mothers with CS, using data from the latest Bangladesh Demographic and Health Survey (BDHS). METHODS:The study is based on data from the 2014 BDHS. BDHS is a nationally representative survey which is conducted periodically and 2014 is the latest of the BDHS conducted. Data collected from 4,627 mothers who gave birth in health care institutions in three years preceding the survey were used in this study. RESULTS:Average age of the mothers was 24.6 years, while their average years of schooling were 3.2. Factors like mother being older, obese, residing in urban areas, first birth, maternal perception of large newborn size, husband being a professional, had higher number of antenatal care (ANC) visits, seeking ANC from private providers, and delivering in a private facility were statistically associated with higher rates of CS. CONCLUSIONS:Bangladesh health system urgently needs policy guideline with monitoring of clinical indications of CS deliveries to avoid unnecessary CS. Strict adherence to this guideline, along with enhance knowledge on the unsafe nature of the unnecessary CS can achieve increased institutional normal delivery in future; otherwise, an emergency procedure may end up being a lucrative practice
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