Association between Household Air Pollution Exposure and Chronic Obstructive Pulmonary Disease Outcomes in 13 Low- and Middle-Income Country Settings

Overcoming challenges of managing chronic obstructive pulmonary disease in low- and middle-income countries

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) ranks among the top three global causes of death, with 90% of fatalities concentrated in low- and middle-income countries (LMICs). The projected rise in COPD burden, especially in LMICs, emphasizes the need to address the challenges for effective control and reversal of this trend. We aimed to provide an overview, and propose potential solutions to these challenges.

AREAS COVERED

We highlight the challenges faced in managing COPD in LMICs and put forward the potential approaches to mitigate the same.

EXPERT OPINION

In LMICs, the effective management of COPD encounters numerous barriers. These include limited access to critical diagnostic services, inadequately trained healthcare personnel, shortages of inhaler medications, oxygen therapy, insufficient access to vaccines, and pulmonary rehabilitation programs. Compounding the above challenges is the late presentation due to misdiagnosis by health workers, and limited access to vital diagnostics. Moreover, the pharmacological armamentarium for optimal COPD therapy, notably inhaled therapies, face constraints in both access and affordability. We propose multi-level and multifaceted interventions to address the urgent need for enhanced respiratory care, human resource capacity building, relevant diagnostic approaches, increased access to medications, government, regional and global efforts to achieve optimal COPD management in LMICs.

Tuberculosis Is Associated with Chronic Hypoxemia among Kenyan Adults (CHAKA): A Case-Control Study

Rationale: Data on risk factors for chronic hypoxemia in low- and middle-income countries are lacking. Objectives: We aimed to quantify the association between potential risk factors and chronic hypoxemia among adults hospitalized in Kenya. Methods: A hospital-based, case-control study was conducted at Moi Teaching and Referral Hospital in Eldoret, Kenya. Adult inpatients were screened on admission and enrolled in a 1:2 case-to-control ratio. Cases were patients with chronic hypoxemia, defined as resting oxygen saturation as measured by pulse oximetry (SpO2) ⩽ 88% on admission and either 1-month postdischarge SpO2 ⩽ 88% or, if they died before follow-up, documented SpO2 ⩽ 88% in the 6 months before enrollment. Control subjects were randomly selected, stratified by sex, among nonhypoxemic inpatients. Data were collected using questionnaires and structured chart review. Regression was used to assess the associations between chronic hypoxemia and age, sex, smoking status, biomass fuel use, elevation, and self-reported history of tuberculosis and human immunodeficiency virus diagnosis. Odds ratios (ORs) and 95% confidence intervals (CIs) are reported. Results: We enrolled 108 chronically hypoxemic cases and 240 nonhypoxemic control subjects into our Chronic Hypoxemia among Kenyan Adults (CHAKA) cohort. In multivariable analysis, compared with control subjects, chronically hypoxemic cases had significantly higher odds of older age (OR, 1.2 per 5-year increase [95% CI, 1.1-1.3]), female sex (OR, 3.6 [95% CI, 1.8-7.2]), current or former tobacco use (OR, 4.7 [95% CI, 2.3-9.6]), and prior tuberculosis (OR, 11.8 [95% CI, 4.7-29.6]) but no increase in the odds of human immunodeficiency virus diagnosis and biomass fuel use. Conclusions: These findings highlight the potential impact of prior tuberculosis on chronic lung disease in Kenya and the need for further studies on posttuberculosis lung disease.

Emission of volatile organic compounds during open fire cooking with wood biomass: Traditional three-stone open fire vs. gasifier cooking stove in rural Kenya

Cooking with wood biomass fuels releases hazardous air pollutants, including volatile organic compounds (VOCs), that often disproportionally affect women and children. This study, conducted in Kwale and Siaya counties in Kenya, employed thermal desorption gas chromatography - mass spectrometry to analyse VOC emissions from cooking with a wood biomass three-stone open fire vs. top-lit updraft gasifier stove. In kitchens with adequate ventilation, total VOC levels increased from 35-252 μg∙m-3 before cooking to 2235-5371 μg∙m-3 during open fire cooking, whereas use of a gasifier stove resulted in reduced emissions from cooking by 48-77 % (506-2778 μg∙m-3). However, in kitchens with poor ventilation, there was only a moderate difference in total VOC levels between the two methods of cooking (9034-9378 μg∙m-3 vs. 6727-8201 μg∙m-3 for the three-stone open fire vs. gasifier stove, respectively). Using a non-target screening approach revealed significantly increased levels of VOCs, particularly benzenoids, oxygenated and heterocyclic compounds, when cooking with the traditional open fire, especially in closed kitchens, highlighting the effects of poor ventilation. Key hazardous VOCs included benzene, naphthalene, phenols and furans, suggesting potential health risks from cooking. In kitchens with good ventilation, use of the gasifier stove markedly reduced emissions of these priority toxic VOCs compared to cooking with an open fire. Thus, substituting open fires with gasifier stoves could help to improve household air quality and alleviate health risks. The study revealed that VOCs were present prior to cooking, possibly originating from previously cooked food (buildup) or the outside environment. VOC emissions were also exacerbated by reduced air flow in high humidity during rainfall, suggesting an area for further research. The findings underscore the importance of adopting cleaner cooking technologies and enhancing kitchen ventilation to mitigate the impacts of VOCs in developing countries.

Residential energy transition and chronic respiratory diseases

Obtaining clean energy is of prime importance for planetary health and sustainable development. We aimed to assess the association between residential energy transition and the risk of chronic respiratory diseases. Using data from the Global Health Observatory and Global Burden of Diseases, Injuries, and Risk Factors Study, we delineated the spatial distribution and temporal trends of the population using clean fuels for cooking at a global scale. In the China Health and Retirement Longitudinal Study, we performed rigorous and well-structured multistage analyses incorporating both cross-sectional and prospective data analyses to examine the associations between solid fuel use, residential energy transition, duration of solid fuel use, and the risk of chronic respiratory diseases. Despite great progress, huge disparities in access to clean energy persist globally. Residential energy transition was associated with a lower risk of chronic respiratory diseases. In the period of 2011-2013, compared with persistent solid fuel users, both participants who switched from solid to clean fuels (adjusted risk ratio [RR] 0.78, 95% confidence interval [CI] 0.62-0.98) and persistent clean fuel users (adjusted RR 0.71, 95% CI 0.57-0.89) had significantly lower risk of chronic respiratory diseases (p < 0.001 for trend). Consistent associations were observed in the period of 2011-2015 and 2011-2018. Household energy transition from solid to clean fuels could reduce the risk of chronic respiratory diseases. This is a valuable lesson for policy-makers and the general public to accelerate energy switching to alleviate the burden of chronic respiratory diseases and achieve health benefits, particularly in low- and middle-income countries.

Household Air Pollution Interventions to Improve Health in Low- and Middle-Income Countries: An Official American Thoracic Society Research Statement

Background: An estimated 3 billion people, largely in low- and middle-income countries, rely on unclean fuels for cooking, heating, and lighting to meet household energy needs. The resulting exposure to household air pollution (HAP) is a leading cause of pneumonia, chronic lung disease, and other adverse health effects. In the last decade, randomized controlled trials of clean cooking interventions to reduce HAP have been conducted. We aim to provide guidance on how to interpret the findings of these trials and how they should inform policy makers and practitioners.Methods: We assembled a multidisciplinary working group of international researchers, public health practitioners, and policymakers with expertise in household air pollution from within academia, the American Thoracic Society, funders, nongovernmental organizations, and global organizations, including the World Bank and the World Health Organization. We performed a literature search, convened four sessions via web conference, and developed consensus conclusions and recommendations via the Delphi method.Results: The committee reached consensus on 14 conclusions and recommendations. Although some trials using cleaner-burning biomass stoves or cleaner-cooking fuels have reduced HAP exposure, the committee was divided (with 55% saying no and 45% saying yes) on whether the studied interventions improved measured health outcomes.Conclusions: HAP is associated with adverse health effects in observational studies. However, it remains unclear which household energy interventions reduce exposure, improve health, can be scaled, and are sustainable. Researchers should engage with policy makers and practitioners working to scale cleaner energy solutions to understand and address their information needs.

Association between cooking fuel exposure and respiratory health: Longitudinal evidence from the China Health and Retirement Longitudinal Study (CHARLS)

The epidemiological evidences for the association between cooking fuel exposure and respiratory health were inconsistent, and repeated-measures prospective evaluation of cooking fuel exposure was still lacking. We assessed the longitudinal association of chronic lung disease (CLD) and lung function with cooking fuel types among Chinese adults aged ≥ 40 years. In this prospective, nationwide representative cohort of the China Health and Retirement Longitudinal Study from 2011 to 2018, 9004 participants from 28 provinces in China were included. CLD was identified based on self-reported physician diagnosis in 2018. Lung function was assessed by peak expiratory flow (PEF) in 2011, 2013 and 2015. Multivariable logistic and linear mixed-effects repeated-measures models were conducted to measure the associations of CLD and PEF with cooking fuel types. Three-level mixed-effects model was performed as sensitivity analysis. Among the participants, 3508 and 3548 participants used persistent solid and clean cooking fuels throughout the survey, and 1948 participants who used solid cooking fuels at baseline switched to clean cooking fuels. Use of persistent clean cooking fuels (adjusted odds ratio [aOR] = 0.73, 95 % confidence interval [CI]: 0.61, 0.88) and switch of solid fuels to clean fuels (aOR = 0.81, 95 % CI: 0.67, 0.98) were associated with lower risk of CLD. The use of clean cooking fuels throughout the survey and switch of solid fuels to clean fuels in 2013 were also significantly associated with higher PEF level. Similar results were observed in stratified analyses and different statistical models. The evidence from CHARLS cohort suggested that reducing solid cooking fuel exposure was associated with lower risk of CLD and better lung function. Given the recent evidence, improving household air quality will reduce the burden of chronic lung diseases.

Sex-differences in COPD: from biological mechanisms to therapeutic considerations

Chronic obstructive pulmonary disease (COPD) is a heterogeneous respiratory condition characterized by symptoms of dyspnea, cough, and sputum production. We review sex-differences in disease mechanisms, structure-function-symptom relationships, responses to therapies, and clinical outcomes in COPD with a specific focus on dyspnea. Females with COPD experience greater dyspnea and higher morbidity compared to males. Imaging studies using chest computed tomography scans have demonstrated that females with COPD tend to have smaller airways than males as well as a lower burden of emphysema. Sex-differences in lung and airway structure lead to critical respiratory mechanical constraints during exercise at a lower absolute ventilation in females compared to males, which is largely explained by sex differences in maximum ventilatory capacity. Females experience similar benefit with respect to inhaled COPD therapies, pulmonary rehabilitation, and smoking cessation compared to males. Ongoing re-assessment of potential sex-differences in COPD may offer insights into the evolution of patterns of care and clinical outcomes in COPD patients over time.

Household unclean fuel use, indoor pollution and self-rated health: risk assessment of environmental pollution caused by energy poverty from a public health perspective

The lack of access to clean energy remains one of the major challenges in the global energy sector. Access to clean, sustainable and affordable energy, outlined in the seventh Sustainable Development Goals (SDG 7) of the United Nations, plays a crucial role in advancing health (SDG 3), as unclean cooking energy may endanger people's health by causing air pollution. However, due to endogeneity problems such as reverse causality, the health consequences of environmental pollution caused by unclean fuel usage are difficult to be scientifically and accurately evaluated. This paper aims to systematically assess the health cost of unclean fuel usage based on tackling endogeneity, using the data from Chinese General Social Survey. The ordinary least squares model, ordered regression methods, instrumental variable approach, penalized machine learning methods, placebo test, and mediation models are applied in this research. Analytical results demonstrate that households' unclean fuel use significantly damages people's health. Specifically, the use of dirty fuel leads to an average of about a one-standard-deviation decline in self-rated health, demonstrating its notable negative effect. The findings are robust to a series of robustness and endogeneity tests. The impact mechanism is that unclean fuel usage reduces people's self-rated health through increasing indoor pollution. Meanwhile, the negative effect of dirty fuel use on health has significant heterogeneity among different subgroups. The consequences are more prominent for the vulnerable groups who are female, younger, living in rural areas and older buildings, with lower socio-economic status and uncovered by social security. Therefore, necessary measures should be taken to improve energy infrastructure to make clean cooking energy more affordable and accessible as well as to enhance people's health. Besides, more attention should be paid to the energy needs of the above specific vulnerable groups faced with energy poverty.

Selected updates on chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is preventable disease and yet it remains the third greatest cause of death worldwide. This review focuses on recent updates in COPD research which have had an impact on our understanding of the epidemiology and pathophysiology of COPD.

RECENT FINDINGS

Epidemiological studies of COPD have moved towards trying to understand the global impact of COPD particularly in low- and middle-income countries where disease prevalence continues to increase. In addition, we are beginning to uncover the impact of air pollution on COPD development with recent work showing a relationship between air pollution and COPD exacerbations. Advances in understanding early origins and early development of COPD have the potential to intervene earlier in the disease course to prevent disease progression. Although biomarkers such as peripheral blood eosinophilia have led to trials of biologic agents in COPD suggesting we may be entering an exciting new biologic era in COPD.

SUMMARY

Recent advances suggest there may be a relationship between air pollution and COPD exacerbations. This requires further research to influence environmental policy. New clinical trials of biologics targeting TH2 inflammation in COPD suggest that targeted treatments with biologics may be a possibility COPD.

Household air pollution and risk of pulmonary tuberculosis in HIV-Infected adults

BACKGROUND

In low- and middle-income countries countries, millions of deaths occur annually from household air pollution (HAP), pulmonary tuberculosis (PTB), and HIV-infection. However, it is unknown whether HAP influences PTB risk among people living with HIV-infection.

METHODS

We conducted a case-control study among 1,277 HIV-infected adults in Bukavu, eastern Democratic Republic of Congo (February 2018 - March 2019). Cases had current or recent (<5y) PTB (positive sputum smear or Xpert MTB/RIF), controls had no PTB. Daily and lifetime HAP exposure were assessed by questionnaire and, in a random sub-sample (n=270), by 24-hour measurements of personal carbon monoxide (CO) at home. We used multivariable logistic regression to examine the associations between HAP and PTB.

RESULTS

We recruited 435 cases and 842 controls (median age 41 years, [IQR] 33-50; 76% female). Cases were more likely to be female than male (63% vs 37%). Participants reporting cooking for >3h/day and ≥2 times/day and ≥5 days/week were more likely to have PTB (aOR 1·36; 95%CI 1·06-1·75) than those spending less time in the kitchen. Time-weighted average 24h personal CO exposure was related dose-dependently with the likelihood of having PTB, with aOR 4·64 (95%CI 1·1-20·7) for the highest quintile [12·3-76·2 ppm] compared to the lowest quintile [0·1-1·9 ppm].

CONCLUSION

Time spent cooking and personal CO exposure were independently associated with increased risk of PTB among people living with HIV. Considering the high burden of TB-HIV coinfection in the region, effective interventions are required to decrease HAP exposure caused by cooking with biomass among people living with HIV, especially women.

Investigating the temporal dynamics of sub-micron particles and particle-bound transition metals in indoor air of a metropolitan city

The present study portrays an association between particle-bound transition metals and children's health. The indoor air quality of the urban metropolitan city households was monitored for four PM sizes, namely PM1.0-2.5, PM0.50-1.0, PM0.25-0.50 and PM<0.25, in major seasons observed in the city; summer and winter. Further transition/heavy metals, viz. Cr, Cu, Fe, Mn, Ni, Pb and Zn, were analysed in PM1-2.5 samples. In order to evaluate the effect, health risk assessment was performed using mathematical and computational model for assessing dermal exposure and dose estimation (multiple path particle dosimetry model version3.0). The study principally targeted the children aged 2-15 years for the health risk assessment. According to the results, for the largest particle size i.e. PM1.0-2.5 the highest deposition was in the head region (49.1%) followed by pulmonary (43.6%) and tracheobronchial region (7.2%), whereas, for the smallest particle size i.e. PM<0.25 the highest deposition was obtained in the pulmonary region (73.0%) followed by the head (13.6%) and TB region (13.2%). Also, the most imperilled group of children with highest dose accumulation was found to be children aged 8-9 years for all particle sizes. Moreover, the dermal exposure dose as evaluated was found to be preeminent for Ni, Zn and Pb. Besides, seasonal variation gesticulated towards elevated concentrations in winter relative to the summer season. Altogether, the study will provide a conception to the researchers in the fields mounting season-specific guidelines and mitigation approaches. Conclusively, the study commends future work focussing on defining the effects of other chemical components on particles and associated transition metal composition along with proper extenuation of the same.

Combined effect of ozone and household air pollution on COPD in people aged less than 50 years old

OBJECTIVES

Air pollution has been suggested as an important risk factor for chronic obstructive pulmonary disease (COPD); however, evidence of interactive effects on COPD between different factors was sparse, especially for young adults. We aimed to assess the combined effects of ambient ozone (O3) and household air pollution on COPD in young individuals.

METHODS

We conducted a population-based study of residents aged 15-50 years in the low-income and middle-income regions of western China. We used multivariable logistic regression models to examine the associations between long-term ozone exposure and COPD in young individuals.

RESULTS

A total of 6537 young cases were identified among the participants, with a COPD prevalence rate of 7.8 (95% CI 7.2% to 8.5%), and most young COPD individuals were asymptomatic. Exposure to household air pollution was associated with COPD in young patients after adjustment for other confounding factors (OR 1.82, 95% CI 1.41 to 2.37). We also found positive associations of COPD with O3 per IQR increase of 20 ppb (OR 1.92, 95% CI 1.59 to 2.32). The individual effects of household air pollution and O3 were 1.68 (95% CI 1.18 to 2.46) and 1.55 (95% CI 0.99 to 2.43), respectively, while their joint effect was 3.28 (95% CI 2.35 to 4.69) with the relative excess risk due to interaction of 1.05 (95% CI 0.33 to 1.78).

CONCLUSIONS

This study concludes that exposure to ambient O3 and household air pollution might be important risk factors for COPD among young adults, and simultaneous exposure to high levels of the two pollutants may intensify their individual effects.

COPD in People with HIV: Epidemiology, Pathogenesis, Management, and Prevention Strategies

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by airflow limitation and persistent respiratory symptoms. People with HIV (PWH) are particularly vulnerable to COPD development; PWH have demonstrated both higher rates of COPD and an earlier and more rapid decline in lung function than their seronegative counterparts, even after accounting for differences in cigarette smoking. Factors contributing to this HIV-associated difference include chronic immune activation and inflammation, accelerated aging, a predilection for pulmonary infections, alterations in the lung microbiome, and the interplay between HIV and inhalational toxins. In this review, we discuss what is known about the epidemiology and pathobiology of COPD among PWH and outline screening, diagnostic, prevention, and treatment strategies.

Household Air Pollution and Risk of Pulmonary Tuberculosis in HIV-Infected Adults

Background

In developing countries, millions of deaths occur annually from household air pollution (HAP), pulmonary tuberculosis (PTB), and HIV-infection. However, it is unknown whether HAP influences PTB risk among people living with HIV-infection.

Methods

We conducted a case-control study among 1,277 HIV-infected adults in Bukavu, eastern Democratic Republic of Congo (February 2018 - March 2019). Cases had current or recent (<5y) PTB (positive sputum smear or Xpert MTB/RIF), controls had no PTB. Daily and lifetime HAP exposure were assessed by questionnaire and, in a random sub-sample (n=270), by 24-hour measurements of personal carbon monoxide (CO) at home. We used multivariable logistic regression to examine the associations between HAP and PTB.

Results

We recruited 435 cases and 842 controls (median age 41 years, [IQR] 33-50; 76% female). Cases were more likely to be female than male (63% vs 37%). Participants reporting cooking for >3h/day and ≥2 times/day and ≥5 days/weekwere more likely to have PTB (aOR 1·36; 95%CI 1·06-1·75) than those spending less time in the kitchen. Time-weighted average 24h personal CO exposure was related dose-dependently with the likelihood of having PTB, with aOR 4·64 (95%CI 1·1-20·7) for the highest quintile [12·3-76·2 ppm] compared to the lowest quintile [0·1-1·9 ppm].

Conclusion

Time spent cooking and personal CO exposure were independently associated with increased risk of PTB among people living with HIV. Considering the high burden of TB-HIV coinfection in the region, effective interventions are required to decrease HAP exposure caused by cooking with biomass among people living with HIV, especially women.

Smoking index and COPD duration as potential risk factors for development of osteoporosis in patients with non-small cell lung cancer - A retrospective case control study evaluated by CT Hounsfield unit

Objective

To investigate the effect of smoking index (calculated as number of cigarettes per day × smoking years) and chronic obstructive pulmonary disease (COPD) duration on osteoporosis (OP)evaluated by opportunistic chest CT in patients with non-small cell lung cancer (NSCLC).

Methods

A total of 101 patients diagnosed with NSCLC were included in our cohort study. Among them, 50 patients with a history of smoking and COPD were assigned to the experimental group, while 51 patients without a history of smoking and COPD were assigned to the control group. Hounsfield unit (HU) value was measured by conventional chest CT to investigate the bone mineral density; and the mean values of axial HU value in the upper, middle and lower parts of T4, T7, T10 and L1 vertebral bodies were measured as the study variables.

Results

There were no significant differences in gender, age, body mass index, type of lung cancer, clinical stage of lung cancer and comorbidities between the two groups (P = 0.938，P = 0.158，P = 0.722,P = 0.596,P = 0.813,P = 0.655). The overall mean HU values of T4, T7, T10, L1 in the experimental group were 116.60 ± 30.67, 110.56 ± 30.03, 109.18 (96.85-122.95), 94.63 (85.20-104.12) and 106.86 ± 22.26, respectively, which were significantly lower than those in the control group (189.55 ± 34.57, 174.54 ± 35.30, 172.73 (156.33-199.50), 158.20 (141.60-179.40) and 177.50 ± 33.49) (P ＜0.05). And in the experimental group, smoking index and COPD duration were significantly and negatively correlated with HU values (r = -0.627, -0.542, P ＜0.05, respectively).

Conclusion

Patients with NSCLC who have a history of smoking and COPD exhibit a notably lower HU value compared to the control groups. Additionally, it has been observed that the smoking index and duration of COPD may be influential factors affecting bone mineral density in NSCLC patients.

Health Equity and Respiratory Diseases in Low- and Middle-Income Countries

Over 80% of the morbidity and mortality related to acute and chronic respiratory diseases occur in low- and middle-income countries (LMICs), a reflection of vast disparities in care for these conditions. Over the next decade, the prevalence of respiratory diseases is expected to increase, as population growth in LMICs exceeds high-income countries (HICs). Pediatric morbidity and mortality from lower respiratory tract infections and asthma occur almost exclusively in LMICs, contributing to a greater loss of quality adjusted life years from these conditions when compared with HICs.

Patient experience with chronic obstructive pulmonary disease: a nationally representative demonstration study on quality and cost of healthcare services

Introduction

Due to insufficient data on patient experience with healthcare system among patients with chronic obstructive pulmonary disease (COPD), particularly in developing countries, this study attempted to investigate the journey of patients with COPD in the healthcare system using nationally representative data in Iran.

Methods

This nationally representative demonstration study was conducted from 2016 to 2018 using a novel machine-learning based sampling method based on different districts' healthcare structures and outcome data. Pulmonologists confirmed eligible participants and nurses recruited and followed them up for 3  months/in 4 visits. Utilization of various healthcare services, direct and indirect costs (including non-health, absenteeism, loss of productivity, and time waste), and quality of healthcare services (using quality indicators) were assessed.

Results

This study constituted of a final sample of 235 patients with COPD, among whom 154 (65.5%) were male. Pharmacy and outpatient services were mostly utilized healthcare services, however, participants utilized outpatient services less than four times a year. The annual average direct cost of a patient with COPD was 1,605.5 USDs. Some 855, 359, 2,680, and 933 USDs were imposed annually on patients with COPD due to non-medical costs, absenteeism, loss of productivity, and time waste, respectively. Based on the quality indicators assessed during the study, the focus of healthcare providers has been the management of the acute phases of COPD as the blood oxygen levels of more than 80% of participants were documented by pulse oximetry devices. However, chronic phase management was mainly missed as less than a third of participants were referred to smoking and tobacco quit centers and got vaccinated. In addition, less than 10% of participants were considered for rehabilitation services, and only 2% completed four-session rehabilitation services.

Conclusion

COPD services have focused on inpatient care, where patients experience exacerbation of the condition. Upon discharge, patients do not receive appropriate follow-up services targeting on preventive care for optimal controlling of pulmonary function and preventing exacerbation.

Cross-sectional validation of the COPD Assessment Test (CAT) among chronic obstructive pulmonary disease patients in rural Uganda

Measuring quality of life is a key component in the management of Chronic Obstructive Pulmonary Disease (COPD). The COPD assessment test (CAT), an easy to administer and shorter instrument than the standard Saint George's respiratory questionnaire (SGRQ), could be an alternative tool for measuring the quality of life of COPD patients in rural Uganda. A cross-sectional study was conducted between June and August 2022, consecutively recruiting 113 COPD patients aged > 40 years from the Low-Dose Theophylline for the management of Biomass-associated COPD (LODOT-BCOPD) study. Upon obtaining consent, participants answered an interviewer administered social demographic, CAT and SGRQ questionnaire. Internal consistency for both SGRQ and CAT was determined using Cronbach's alpha coefficient and values > 0.7 were considered acceptable while correlations were determined using Spearman's rank correlation. Limits of Agreement were visualised using Bland Altman and pair plots. Of the 113 participants, 51 (45.1%) were female. The mean age was 64 ± 12 years, 19 (16.8%) had history of smoking while majority (112 (99.1%)) reported use of firewood for cooking. There was a strong correlation of 0.791 (p < 0.001) between the CAT and SGRQ total scores with a high internal consistency of CAT, Cronbach's alpha coefficient of 0.924 (0.901-0.946). The agreement between the absolute CAT scores and the SGRQ scores was good with a mean difference of -0.932 (95% Confidence Interval: -33.49-31.62). In summary, CAT has an acceptable validity and can be used as an alternative to the SGRQ to assess the quality of life of COPD patients in rural Uganda.

Household Air Pollution and Adult Lung Function Change, Respiratory Disease, and Mortality across Eleven Low- and Middle-Income Countries from the PURE Study

BACKGROUND

Globally, household air pollution (HAP) is a major environmental hazard that affects respiratory health. However, few studies have examined associations between HAP and lung function decline and respiratory disease and mortality.

METHODS

We used data from the Prospective Urban and Rural Epidemiology study and examined adults residing in 240 rural communities in 11 low- and middle-income countries where HAP from cooking with solid fuels is common. Spirometry was conducted for 28,574 individuals at baseline and 12,489 individuals during follow-up (mean of 8 y between spirometry measures). In cross-sectional analyses, we compared lung function measurements [forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio] in those who used solid fuels for cooking in comparison with clean fuels. Using repeated measurements of lung function, we examined the percent change in lung function measures per year, comparing individuals by baseline fuel type and individuals who used solid fuels at baseline but switched to clean fuels during follow-up. We also examined associations with prospective health events (any respiratory diseases, respiratory disease hospitalizations, and all-cause mortality).

RESULTS

In adjusted cross-sectional models, use of solid fuel in comparison with clean fuels was associated with lower FEV1 of -17.5mL (95% CI: -32.7, -2.3) and FVC of -14.4mL (95% CI: -32.0, 3.2), but not FEV1/FVC. In longitudinal analyses, individuals who switched from solid fuels to clean cooking fuels during follow-up (n=3,901, 46% of those using solid fuel at baseline), showed no differences in the annual rate of change in FEV1 or FVC, but had small improvements in FEV1/FVC change (0.2% per year, 95% CI: 0.03, 0.3). Individuals who switched from solid to clean fuels had a decreased hazard ratio for respiratory events of 0.76 (95% CI: 0.57, 1.00) in comparison with persistent solid fuel users, which was not attenuated by lung function measures.

CONCLUSION

We observed modest associations between HAP exposure and lung function, lung function change, and respiratory disease and mortality. https://doi.org/10.1289/EHP11179.

An ensemble mixed spatial model in estimating long-term and diurnal variations of PM2.5 in Taiwan

Meteorology, human activities, and other emission sources drive diurnal cyclic patterns of air pollution. Previous studies mainly focused on the variation of PM_2.5 concentrations during daytime rather than nighttime. In addition, assessing the spatial variations of PM_2.5 in large areas is a critical issue for environmental epidemiological studies to clarify the health effects from PM_2.5 exposures. In terms of air pollution spatial modelling, using only a single model might lose information in capturing spatial and temporal correlation between predictors and pollutant levels. Hence, this study aimed to propose an ensemble mixed spatial model that incorporated Kriging interpolation, land-use regression (LUR), machine learning, and stacking ensemble approach to estimate long-term PM_2.5 variations for nearly three decades in daytime and nighttime. Three steps of model development were applied: 1) linear based LUR and Hybrid Kriging-LUR were used to determine influential predictors; 2) machine learning algorithms were used to enhance model prediction accuracy; 3) predictions from the selected machine learning models were fitted and evaluated again to build the final ensemble mixed spatial model. The results showed that prediction performance increased from 0.514 to 0.895 for daily, 0.478 to 0.879 for daytime, and 0.523 to 0.878 for nighttime when applying the proposed ensemble mixed spatial model compared with LUR. Results of overfitting test and extrapolation ability test confirmed the robustness and reliability of the developed models. The distance to the nearest thermal power plant, density of soil and pebbles fields, and funeral facilities might affect the variation of PM_2.5 levels between daytime and nighttime. The PM_2.5 level was higher in daytime compared with nighttime with little difference, revealing the importance of estimating nighttime PM_2.5 variations. Our findings also clarified the emission sources in daytime and nighttime, which serve as valuable information for air pollution control strategies establishment.

COPD in Africa: risk factors, hospitalisation, readmission and associated outcomes-a systematic review and meta-analysis

BACKGROUND

This review aims to synthesise available evidence on the prevalence of chronic obstructive pulmonary disease (COPD), associated risk factors, hospitalisations and COPD readmissions in Africa.

METHOD

Using the Met-Analyses and Systematic Reviews of Observational Studies guideline, electronic databases were searched from inception to 1 October 2021. The quality of studies was assessed using the Newcastle-Ottawa Scale. Evidence from retrieved articles was synthesised, and a random-effect model meta-analysis was conducted. The protocol was registered on PROSPERO.

RESULTS

Thirty-nine studies met the inclusion criteria, with 13 included in the meta-analysis. The prevalence of COPD varied between the Global Initiative for Chronic Obstructive Lung Disease (2%-24%), American Thoracic Society/European Respiratory Society (1%-17%) and Medical Research Council chronic bronchitis (2%-11%) criteria, respectively. Increasing age, wheezing and asthma were consistent risk factors for COPD from studies included in the narrative synthesis. Our meta-analysis indicated that prior tuberculosis ((OR 5.98, 95% CI 4.18 to 8.56), smoking (OR 2.80, 95% CI: 2.19 to 3.59) and use of biomass fuel (OR 1.52, 95% CI: 1.39 to 1.67)) were significant risk factors for COPD. Long-term oxygen therapy (HR 4.97, 95% CI (1.04 to 23.74)) and frequent hospitalisation (≥3 per year) (HR 11.48, 95% CI (1.31 to 100.79)) were risk factors associated with 30-day COPD readmission.

CONCLUSION

This study not only highlights specific risk factors for COPD risk in Africa but also demonstrates the paucity and absence of research in several countries in a continent with substantial COPD-related mortality. Our findings contribute towards the development of evidence-based clinical guidelines for COPD in Africa.PROSPERO registration numberCRD42020210581.

Awareness of COPD and Its Risk Factors Among the Adult Population of the Aseer Region, Saudi Arabia

Introduction

Epidemiological studies are urgently needed to assess the prevalence of COPD in the region to determine the baseline, against which the future trends in the risk factor levels can be assessed and preventive strategies be planned to promote health among the population. Therefore, this study was undertaken to assess the awareness of COPD and its risk factors in Saudi Arabia.

Materials and Methods

The cross-sectional study was conducted among the general adult population aged 18 years and above living in the Aseer region. A minimum sample of 385 was targeted, using the Raosoft sample size calculator. An online questionnaire was prepared in both English and Arabic language using Google forms and distributed among participants through social media.

Results

It was observed that less than one-third (116, 30.12%) of the study population had ever heard about COPD. Nearly one-third spent time with smokers. Among all, 223 (57.3%) respondents had never heard and 46 (11.9%) respondents did not know anything about COPD. The majority correctly knew that the lungs are the primary organ affected by COPD (92, 79.3%). Age, sex, marital status, income, and occupation showed a significant association with COPD awareness. Nearly 41.4% knew that COPD progresses exclusively with age, COPD is more expensive for society than lung cancer (49.0%), cigarette smoking affects COPD (34.5%), COPD is fully recoverable with short-term antibiotics (35.0%), COPD lasts more than 18 months (48.1%), COPD can worsen with smoke exposure (37.4%), lead to disability (46.7%) and quitting smoking has an important role in preventing COPD (34.0%).

Conclusion

The awareness regarding the disease was low among the respondents. Only one-third correctly knew that quitting smoking has an important role in preventing COPD. This study projects an urgent need of improving awareness of COPD and its risk factors in the general population.

Solid Fuel Use and the Progression of Multimorbidity in Middle-Aged Chinese Participants: A Prospective Cohort Study

Objectives: This study aimed to examine the association of solid fuel use for cooking and heating with the progression of multimorbidity. Methods: A total of 5,437 participants from the China Health and Retirement Longitudinal Study were included. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of the independent and joint effects of solid fuel use for cooking and heating with the progression of multimorbidity. Results: The proportion of participants reporting solid fuel use for both cooking and heating was 59.0% at baseline. Solid fuel use for both cooking and heating was associated with the progression of multimorbidity (adjusted OR: 1.42, 95% CI: 1.19-1.70), compared with clean fuel use for both. Conclusion: Solid fuel use for cooking and heating play an important role in the progression of multimorbidity. Therefore, solid fuel reduction should be considered in developing multimorbidity control and prevention programmes.

Recognising the importance of chronic lung disease: a consensus statement from the Global Alliance for Chronic Diseases (Lung Diseases group)

BACKGROUND

Chronic respiratory diseases are disorders of the airways and other structures of the lung, and include chronic obstructive pulmonary disease (COPD), lung cancer, asthma, bronchiectasis, interstitial lung diseases, occupational lung diseases and pulmonary hypertension. Through this article we take a broad view of chronic lung disease while highlighting (1) the complex interactions of lung diseases with environmental factors (e.g. climate change, smoking and vaping) and multimorbidity and (2) proposed areas to strengthen for better global patient outcomes.

CONCLUSION

We suggest new directions for the research agenda in high-priority populations and those experiencing health disparities. We call for lung disease to be made a research priority with greater funding allocation globally.

Associations of cooking fuel types and daily cooking duration with sleep quality in rural adults: Effect modification of kitchen ventilation

BACKGROUND

Associations of combined different cooking fuel types and cooking duration with sleep quality were scarcely reported. This study aimed to explore the associations of exposure to household air pollution (HAP) from different cooking fuel types and cooking duration with sleep quality and examine the effect modification of kitchen ventilation on these associations.

METHODS

A total of 28,135 eligible participants were obtained from the Henan rural cohort study. Sleep quality was assessed by the Pittsburgh sleep quality index (PSQI), and participants with a PSQI score > 5 were identified as having poor sleep quality. A questionnaire was used to collect the cooking fuel types, cooking frequency, cooking duration, and kitchen ventilation. The average daily cooking duration was calculated as the cooking frequency per week multiplied by the cooking duration for each meal divided by 7.

RESULTS

Both domestic fuel use and cooking duration were positively related to poor sleep quality. The solid fuel users with a cooking duration ≥1.5 h/day had a higher prevalence of poor sleep quality (OR: 1.390, 95% CI: 1.233, 1.567), relative to those who never cooked. Notably, the estimated OR and 95% CI for poor sleep quality of clean fuel users with a cooking duration <1.5 h/day plus mechanical or natural ventilation versus those who never cooked was 1.05 (0.933, 1.187) or 1.306 (1.163, 1.466) and these associations were modified by kitchen ventilation.

CONCLUSION

Positive associations of combined different cooking fuel types and cooking duration with the prevalence of poor sleep quality were attenuated by kitchen ventilation, implying that installing mechanical ventilation may be an effective measure to improve sleep quality in low- and middle-income countries. These results need to be confirmed by future studies, which measure HAP more accurately using personal monitoring devices or behavior diaries.

Development and validation of an interstitial lung disease exposure questionnaire for sub-Saharan Africa

Background

American Thoracic Society/European Respiratory Society guidelines recommend context-specific exposure assessments to diagnose interstitial lung disease (ILD). In sub-Saharan Africa, ILD diagnoses are rare, and locally validated ILD exposure questionnaires are not used.

Methods

A physician-administered ILD exposure questionnaire was developed using a four-step mixed-methods modified Delphi approach. First, ILD questionnaires from high-income countries and data from Pneumotox were reviewed, compiled and face-validated. Second, a local pilot group of ILD experts ranked item relevance using a Likert scale and suggested additions. Third, the questionnaire format and pilot rankings were addressed in a focus group discussion that was analysed using grounded theory. Finally, following focus group discussion modifications, the resulting items (with three duplicate item groups for evaluation of internal consistency) were ranked for importance by members of the Pan-African Thoracic Society (PATS).

Results

Face validation resulted in 82 items in four categories: "Smoking and Drugs", "Environmental Exposures", "Occupations" and "Medications". Pilot group (n=10) ranking revealed 27 outliers and 30 novel suggestions. Focus group (n=12) discussion resulted in 10 item deletions, 14 additions and 22 re-wordings; themes included desire for extensive questionnaires and stigma sensitivity. Final validation involved 58 PATS members (mean±sd age 46±10.6  years, 76% male, from 17 countries) ranking 84 items derived from previous steps and three duplicate question groups. The questionnaire was internally consistent (Cronbach's α >0.80) and ultimately included 73 items.

Conclusion

This mixed-methods study included experts from 17 countries in sub-Saharan Africa and successfully developed a 73-item ILD exposure questionnaire for sub-Saharan Africa. African pulmonary experts valued region-specific additions and ranked several items from existing ILD questionnaires as unimportant.

Previous tuberculosis disease as a risk factor for chronic obstructive pulmonary disease: a cross-sectional analysis of multicountry, population-based studies

Background

Risk factors for COPD in high-income settings are well understood; however, less attention has been paid to contributors of COPD in low-income and middle-income countries (LMICs) such as pulmonary tuberculosis. We sought to study the association between previous tuberculosis disease and COPD by using pooled population-based cross-sectional data in 13 geographically diverse, low-resource settings.

Methods

We pooled six cohorts in 13 different LMIC settings, 6 countries and 3 continents to study the relationship between self-reported previous tuberculosis disease and lung function outcomes including COPD (defined as a postbronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) below the lower limit of normal). Multivariable regressions with random effects were used to examine the association between previous tuberculosis disease and lung function outcomes.

Results

We analysed data for 12 396 participants (median age 54.0 years, 51.5% male); 332 (2.7%) of the participants had previous tuberculosis disease. Overall prevalence of COPD was 8.8% (range 1.7%–15.5% across sites). COPD was four times more common among those with previous tuberculosis disease (25.7% vs 8.3% without previous tuberculosis disease, p<0.001). The adjusted odds of having COPD was 3.78 times higher (95% CI 2.87 to 4.98) for participants with previous tuberculosis disease than those without a history of tuberculosis disease. The attributable fraction of COPD due to previous tuberculosis disease in the study sample was 6.9% (95% CI 4.8% to 9.6%). Participants with previous tuberculosis disease also had lower prebronchodilator Z-scores for FEV1(−0.70, 95% CI −0.84 to −0.55), FVC (−0.44, 95% CI −0.59 to −0.29) and the FEV1:FVC ratio (−0.63, 95% CI −0.76 to −0.51) when compared with those without previous tuberculosis disease.

Conclusions

Previous tuberculosis disease is a significant and under-recognised risk factor for COPD and poor lung function in LMICs. Better tuberculosis control will also likely reduce the global burden of COPD.

Association between waist circumference change and incident chronic obstructive pulmonary disease among Chinese adults: a 10-year cohort study

The aim of our study was to investigate waist circumference (WC) change and the risk of incident chronic obstructive pulmonary disease (COPD) among Chinese adults. A total of 8164 participants aged > 18 years who attended health examinations with repeat measurements of WC and lung function [forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁)] from 2010 to 2019 were recruited. WC change was categorized as ≤  - 2.5%, - 2.5 to 2.5%, 2.5% to 5% and > 5% according to sex. Modified Poisson regression models were used to assess the association of WC gain and the risk of COPD. During the 10-year follow-up, a total of 917 COPD cases were identified. From baseline to follow-up, the mean FEV₁ decreased from 3.20 to 2.79L among male participants and 2.28-1.95L among female participants. Compared with participants who did not have abdominal obesity, at either, baseline or follow-up, participants with abdominal obesity of both sexes after the follow-up were associated with a greater risk of COPD regardless of abdominal obesity at baseline. The risk of incident COPD increased 19% among male participants (RR = 1.19, 95%CI = 1.04-1.48) and 14% among female participants (RR = 1.14, 95%CI = 1.01-1.40) when WC gain increased > 5% during the 10-year follow-up. The COPD risk decreased 18% among male participants with a WC change ≤  - 2.5% (RR = 0.82, 95%CI = 0.67-0.99). The risk of incident COPD was positively associated with increasing WC among Chinese adults of both sexes.

Towards the elimination of chronic obstructive pulmonary disease: a Lancet Commission

Despite substantial progress in reducing the global impact of many non-communicable diseases, including heart disease and cancer, morbidity and mortality due to chronic respiratory disease continues to increase. This increase is driven primarily by the growing burden of chronic obstructive pulmonary disease (COPD), and has occurred despite the identification of cigarette smoking as the major risk factor for the disease more than 50 years ago. Many factors have contributed to what must now be considered a public health emergency: failure to limit the sale and consumption of tobacco products, unchecked exposure to environmental pollutants across the life course, and the ageing of the global population (partly as a result of improved outcomes for other conditions). Additionally, despite the heterogeneity of COPD, diagnostic approaches have not changed in decades and rely almost exclusively on post-bronchodilator spirometry, which is insensitive for early pathological changes, underused, often misinterpreted, and not predictive of symptoms. Furthermore, guidelines recommend only simplistic disease classification strategies, resulting in the same therapeutic approach for patients with widely differing conditions that are almost certainly driven by variable pathophysiological mechanisms. And, compared with other diseases with similar or less morbidity and mortality, the investment of financial and intellectual resources from both the public and private sector to advance understanding of COPD, reduce exposure to known risks, and develop new therapeutics has been woefully inadequate.

Personal and household PM2.5 and black carbon exposure measures and respiratory symptoms in 8 low- and middle-income countries

BACKGROUND

Household air pollution (HAP) from cooking with solid fuels has been associated with adverse respiratory effects, but most studies use surveys of fuel use to define HAP exposure, rather than on actual air pollution exposure measurements.

OBJECTIVE

To examine associations between household and personal fine particulate matter (PM_2.5) and black carbon (BC) measures and respiratory symptoms.

METHODS

As part of the Prospective Urban and Rural Epidemiology Air Pollution study, we analyzed 48-h household and personal PM_2.5 and BC measurements for 870 individuals using different cooking fuels from 62 communities in 8 countries (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Self-reported respiratory symptoms were collected after monitoring. Associations between PM_2.5 and BC exposures and respiratory symptoms were examined using logistic regression models, controlling for individual, household, and community covariates.

RESULTS

The median (interquartile range) of household and personal PM_2.5 was 73.5 (119.1) and 65.3 (91.5) μg/m³, and for household and personal BC was 3.4 (8.3) and 2.5 (4.9) x10^-5 m^-1, respectively. We observed associations between household PM_2.5 and wheeze (OR: 1.25; 95%CI: 1.07, 1.46), cough (OR: 1.22; 95%CI: 1.06, 1.39), and sputum (OR: 1.26; 95%CI: 1.10, 1.44), as well as exposure to household BC and wheeze (OR: 1.20; 95%CI: 1.03, 1.39) and sputum (OR: 1.20; 95%CI: 1.05, 1.36), per IQR increase. We observed associations between personal PM_2.5 and wheeze (OR: 1.23; 95%CI: 1.00, 1.50) and sputum (OR: 1.19; 95%CI: 1.00, 1.41). For household PM_2.5 and BC, associations were generally stronger for females compared to males. Models using an indicator variable of solid versus clean fuels resulted in larger OR estimates with less precision.

CONCLUSIONS

We used measurements of household and personal air pollution for individuals using different cooking fuels and documented strong associations with respiratory symptoms.

Burden of chronic obstructive pulmonary disease and its attributable risk factors in 204 countries and territories, 1990-2019: results from the Global Burden of Disease Study 2019

OBJECTIVE

To report the global, regional, and national burden of chronic obstructive pulmonary disease (COPD) and its attributable risk factors between 1990 and 2019, by age, sex, and sociodemographic index.

DESIGN

Systematic analysis.

DATA SOURCE

Global Burden of Disease Study 2019.

MAIN OUTCOME MEASURES

Data on the prevalence, deaths, and disability adjusted life years (DALYs) of COPD, and its attributable risk factors, were retrieved from the Global Burden of Disease 2019 project for 204 countries and territories, between 1990 and 2019. The counts and rates per 100 000 population, along with 95% uncertainty intervals, were presented for each estimate.

RESULTS

In 2019, 212.3 million prevalent cases of COPD were reported globally, with COPD accounting for 3.3 million deaths and 74.4 million DALYs. The global age standardised point prevalence, death, and DALY rates for COPD were 2638.2 (95% uncertainty intervals 2492.2 to 2796.1), 42.5 (37.6 to 46.3), and 926.1 (848.8 to 997.7) per 100 000 population, which were 8.7%, 41.7%, and 39.8% lower than in 1990, respectively. In 2019, Denmark (4299.5), Myanmar (3963.7), and Belgium (3927.7) had the highest age standardised point prevalence of COPD. Egypt (62.0%), Georgia (54.9%), and Nicaragua (51.6%) showed the largest increases in age standardised point prevalence across the study period. In 2019, Nepal (182.5) and Japan (7.4) had the highest and lowest age standardised death rates per 100 000, respectively, and Nepal (3318.4) and Barbados (177.7) had the highest and lowest age standardised DALY rates per 100 000, respectively. In men, the global DALY rate of COPD increased up to age 85-89 years and then decreased with advancing age, whereas for women the rate increased up to the oldest age group (≥95 years). Regionally, an overall reversed V shaped association was found between sociodemographic index and the age standardised DALY rate of COPD. Factors contributing most to the DALYs rates for COPD were smoking (46.0%), pollution from ambient particulate matter (20.7%), and occupational exposure to particulate matter, gases, and fumes (15.6%).

CONCLUSIONS

Despite the decreasing burden of COPD, this disease remains a major public health problem, especially in countries with a low sociodemographic index. Preventive programmes should focus on smoking cessation, improving air quality, and reducing occupational exposures to further reduce the burden of COPD.

Prevalence and incidence of chronic obstructive pulmonary disease in Latin America and the Caribbean: a systematic review and meta-analysis

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) remains one of the leading causes of morbidity and mortality worldwide, and its epidemiology in Latin America and the Caribbean is not well described. The aim of this study was to evaluate the prevalence and incidence of COPD in Latin America and the Caribbean.

METHODS

We searched systematically in Web of Science (WoS)/Core Collection, WoS/MEDLINE, WoS/Scielo, Scopus, PubMed, and Embase from 2010 to 2021. Studies assessing the prevalence and incidence of COPD according to the GOLD classification were included. The overall prevalence of COPD was calculated as a function of the general population using a random-effects model.

RESULTS

20 studies (19 cross-sectional and 1 cohort) met the inclusion criteria. The prevalence of COPD in the general population older than 35 years was 8.9%. The prevalence in men was 13.7% and in women 6.7%. The prevalence in smokers and ex-smokers was 24.3%. The incidence in the general population of COPD according to one study was 3.4% at 9 years of follow-up.

CONCLUSIONS

COPD is prevalent in Latin America, especially in men and in smokers and ex-smokers. Further prevalence and incidence studies in the general population are needed, as well as health policies and strategies to address the disease.

Association of ambient and household air pollution with lung function in young adults in an peri-urban area of South-India: A cross-sectional study

OBJECTIVE

Although there is evidence for the association between air pollution and decreased lung function in children, evidence for adolescents and young adults is scarce. For a peri-urban area in India, we evaluated the association of ambient PM_2.5 and household air pollution with lung function for young adults who had recently attained their expected maximum lung function.

METHODS

We measured, using a standardized protocol, forced expiratory volume in the first second (FEV₁) and forced vital capacity (FVC) in participants aged 20-26 years from the third follow-up of the population-based APCAPCS cohort (2010-2012) in 28 Indian villages. We estimated annual average PM_2.5outdoors at residence using land-use regression. Biomass cooking fuel (a proxy for levels of household air pollution) was self-reported. We fitted a within-between linear-mixed model with random intercepts by village, adjusting for potential confounders.

RESULTS

We evaluated 1,044 participants with mean age of 22.8 (SD = 1) years (range 20-26 years); 327 participants (31%) were female. Only males reported use of tobacco smoking (9% of all participants, 13% of males). The mean ambient PM_2.5 exposure was 32.9 (SD = 2.8) µg/m³; 76% reported use of biomass as cooking fuel. The adjusted association between 1 µg/m³ increase in PM_2.5 was -27 ml (95% CI, -89 to 34) for FEV₁ and -5 ml (95% CI, -93 to 76) for FVC. The adjusted association between use of biomass was -112 ml (95% CI, -211 to -13) for FEV₁ and -142 ml (95% CI, -285 to 0) for FVC. The adjusted association was of greater magnitude for those with unvented stove (-158 ml, 95% CI, -279 to -36 for FEV₁ and -211 ml, 95% CI, -386 to -36 for FVC).

CONCLUSIONS

We observed negative associations between ambient PM_2.5 and household air pollution and lung function in young adults who had recently attained their maximum lung function.

Assessing the Effects of Stove Use Patterns and Kitchen Chimneys on Indoor Air Quality during a Multiyear Cookstove Randomized Control Trial in Rural India

We conducted indoor air quality (IAQ) measurements during a multiyear cookstove randomized control trial in two rural areas in northern and southern India. A total of 1205 days of kitchen PM_2.5 were measured in control and intervention households during six ∼3 month long measurement periods across two study locations. Stoves used included traditional solid fuel (TSF), improved biomass, and liquefied petroleum gas (LPG) models. Intent-to-treat analysis indicates that the intervention reduced average 24 h PM_2.5 and black carbon in only one of the two follow-up measurement periods in both areas, suggesting mixed effectiveness. Average PM_2.5 levels were ∼50% lower in households with LPG (for exclusive LPG use: >75% lower) than in those without LPG. PM_2.5 was 66% lower in households making exclusive use of an improved chimney stove versus a traditional chimney stove and TSF-exclusive kitchens with a built-in chimney had ∼60% lower PM_2.5 than those without a chimney, indicating that kitchen ventilation can be as important as the stove technology in improving IAQ. Diurnal trends in real-time PM_2.5 indicate that kitchen chimneys were especially effective at reducing peak concentrations, which leads to decreases in daily PM_2.5 in these households. Our data demonstrate a clear hierarchy of IAQ improvement in real world, "stove-stacking" households, driven by different stove technologies and kitchen characteristics.

Mediating Factors Explaining the Associations between Solid Fuel Use and Self-Rated Health among Chinese Adults 65 Years and Older: A Structural Equation Modeling Approach

Exposure to indoor air pollution from cooking with solid fuel has been linked with the health of elderly people, although the pathway to their association is unclear. This study aimed to investigate the mediating effects between solid fuel use and self-rated health by using structural equation modeling (SEM) with the baseline data from Chinese Longitudinal Healthy Longevity Survey (CLHLS). We conducted a cross-sectional survey among 7831 elderly people aged >65 years from the CLHLS. SEM was used to analyze the pathways underlying solid fuel use and self-rated health. We estimated indirect effects of sleep quality (β = −0.027, SE = 0.006), cognitive abilities (β = −0.006, SE = 0.002), depressive symptoms (β = −0.066, SE = 0.007), systolic blood pressure (β = 0.000, SE = 0.000), and BMI (β = −0.000, SE = 0.000) on the association between solid fuel and the self-rated health using path analysis. Depressive symptoms emerged as the strongest mediator in the relationship between solid fuel use and self-rated health in the elderly. Interventions targeting sleep quality, cognitive abilities, depressive symptoms, systolic blood pressure, and BMI could greatly reduce the negative effects of solid fuel use on the health of the elderly population.

Global burden of chronic obstructive pulmonary disease attributable to ambient particulate matter pollution and household air pollution from solid fuels from 1990 to 2019

We aimed to estimate the spatiotemporal trends in the global burden of chronic obstructive pulmonary disease (COPD) attributable to both household air pollution from solid fuels (HAP) and ambient particulate matter (APM) from 1990 to 2019 and compared the possible differences between the burdens attributable to APM and HAP. The number of deaths, disability-adjusted life-years (DALYs), and years of life lost (YLLs) of COPD attributable to HAP from solid fuels and APM during 1990-2019 were extracted from the Global Burden of Diseases Study 2019. The proportion of YLLs in DALYs and average YLLs per COPD death were also calculated. Subgroup analyses by sex, age, and socio-demographic index (SDI) were conducted. The estimated annual percentage change (EAPC) was used to assess the temporal trend of age-standardized rate of mortality (ASMR) and DALYs (ASDR). Over the past 30 years, we observed a clear downward trend in COPD deaths attributable to HAP and an upward trend by 97.61% in COPD deaths attributable to APM. The global COPD burden attributable to APM in 2019 was higher than those due to HAP, except in low-SDI regions. For both HAP and APM, YLLs continued to predominate in DALYs of COPD, with an average YLLs per death of more than 10 years in different regions. The ASMR was higher in males and lower in high-SDI regions. The ASMR and ASDR attributable to HAP decreased globally in all age groups during 1990-2019, while those attributable to APM increased among people older than 80 years and in regions with lower SDI. Our study reveals an increasing trend in APM-attributable COPD burden over the past three decades. Comparatively, the global burden due to HAP decreased markedly, but it was still pronounced in low-SDI regions. Continued efforts on PM mitigation are needed for COPD prevention.

Chronic obstructive pulmonary disease in never-smokers: risk factors, pathogenesis, and implications for prevention and treatment

Chronic obstructive pulmonary disease (COPD) was traditionally thought to be caused by tobacco smoking. However, recognition of the importance of non-smoking-related risk factors for COPD has increased over the past decade, with evidence on the burden, risk factors, and clinical presentations of COPD in never-smokers. About half of all COPD cases worldwide are due to non-tobacco-related risk factors, which vary by geographical region. These factors include air pollution, occupational exposures, poorly controlled asthma, environmental tobacco smoke, infectious diseases, and low socioeconomic status. Impaired lung growth during childhood, caused by a range of early-life exposures, is associated with an increased risk of COPD. Potential mechanisms for the pathogenesis of COPD in never-smokers include inflammation, oxidative stress, airway remodelling, and accelerated lung ageing. Compared with smokers who develop COPD, never-smokers with COPD have relatively mild chronic respiratory symptoms, little or no emphysema, milder airflow limitation, and fewer comorbidities; however, exacerbations can still be frequent. Further research-including epidemiological, translational, clinical, and implementation studies-is needed to address gaps in understanding and to advance potential solutions to reduce the burden of COPD in never-smokers.

A high environmental composite quality factor score was associated with the risk of sick building syndrome among adults in northeast China

OBJECTIVES

Epidemiological evidence regarding the association between the combination of indoor and outdoor neighborhood pollution and sick building syndrome (SBS) among adults is limited and inconsistent. A cross-sectional study was conducted to investigate the association between the environmental composite quality factor score and SBS among adults.

METHODS

This study included 2594 females and 666 males aged 18-77 years enrolled from the Northeast China. The environmental composite quality factor score was computed based on factors potentially associated with SBS risk, including the outdoor neighborhood pollution sources (the housing on the street, the presence of pollutants within 100 m of the house (gutters, garbage stations, noise, chemical pollution, and dust pollution), and the presence of arterial roads, factories, and chimneys) and indoor pollution sources (redecoration, clean fuel used for heating/cooking, cooking oil fume (COF) outside kitchen, using of mosquito coil or repellent, and using of incense). We performed multivariate logistic regression analysis to calculate the odds ratios (ORs) and 95% confidence intervals (95%CIs) between environmental composite quality factor score, indoor pollution composite factor score, outdoor neighborhood pollution composite factor score, and SBS adjustment for covariates. Further, we also did the stratified analysis and constructed a weighted score to verify the results.

RESULTS

Compared with the lowest environmental composite quality factor score, the ORs of the highest scores were: 1.58 (95% CI, 1.20-2.27, P_trend = 0.001) for general symptoms; 1.73 (95% CI, 1.35-2.23, P_trend < 0.001) for mucosal symptoms and 1.75 (95% CI, 1.34-2.29, P_trend < 0.001) for dermal symptoms and 1.81 (95% CI, 1.36-2.42, P_trend < 0.001) for all of the three symptoms. We also observed similar patterns with the using of weighted scores and stratified analysis.

CONCLUSION

Higher exposure to indoor pollution sources and outdoor pollution sources near the residence may be associated with a higher risk of SBS in adults in northeast China.

Household air pollution and COPD: cause and effect or confounding by other aspects of poverty?

SETTING :

Household air pollution (HAP) and chronic obstructive pulmonary disease (COPD) are both major public health problems, reported to cause around 4 million and 3 million deaths every year, respectively. The great majority of these deaths, as well as the burden of disease during life is felt by people in low- and middle-income countries (LMICs).

OBJECTIVE AND DESIGN :

The extent to which HAP causes COPD is controversial; we therefore undertook this review to offer a viewpoint on this from the Global Initiative for COPD (GOLD).

RESULTS :

We find that while COPD is well-defined in many studies on COPD and HAP, there are major limitations to the definition and measurement of HAP. It is thus difficult to disentangle HAP from other features of poverty that are themselves associated with COPD. We identify other limitations to primary research studies, including the use of cross-sectional designs that limit causal inference.

CONCLUSION :

There is substantial preventable morbidity and mortality associated with HAP, COPD and poverty, separately and together. Although it may not be possible to define clear causal links between HAP and COPD, there is a clear urgency to reduce the avoidable burden of disease these inflict on the world’s poor.

Chronic obstructive pulmonary disease in sub-Saharan Africa

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and an important cause of death in sub-Saharan Africa (SSA). We conducted a systematic review and meta-analysis on the prevalence of and risk factors for COPD in SSA.METHODS: We conducted a protocol-driven systematic literature search in MEDLINE, EMBASE, CINAHL and Global Health, supplemented by a manual search of the abstracts from thoracic conference proceedings from 2017 to 2020. We did a meta-analysis of COPD prevalence and its association with current smoking.RESULTS: We identified 831 titles, of which 27 were eligible for inclusion in the review and meta-analysis. The population prevalence of COPD ranged from 1.7% to 24.8% (pooled prevalence: 8%, 95% CI 6-11). An increased prevalence of COPD was associated with increasing age, smoking and biomass smoke exposure. The pooled odds ratio for the effect of current smoking (vs. never smoked) on COPD was 2.20 (95% CI 1.62-2.99).CONCLUSION: COPD causes morbidity and mortality in adults in SSA. Smoking is an important risk factor for COPD in SSA, and this exposure needs to be reduced through the combined efforts of clinicians, researchers and policymakers to address this debilitating and preventable lung disease.

Women's COPD

Chronic obstructive pulmonary disease (COPD) is no longer a respiratory disease that predominantly affects men, to the point where the prevalence among women has equaled that of men since 2008, partly due to their increasing exposure to tobacco and to biomass fuels. Indeed, COPD has become the leading cause of death in women in the USA. A higher susceptibility of female to smoking and pollutants could explain this phenomenon. Besides, the clinical presentation appears different among women with more frequent breathlessness, anxiety or depression, lung cancer (especially adenocarcinoma), undernutrition and osteoporosis. Quality of life is also more significantly impaired in women. The theories advanced to explain these differences involve the role of estrogens, smaller bronchi, impaired gas exchange in the lungs and smoking habits. Usual medications (bronchodilators, ICS) demonstrated similar trends for exacerbation prevention and lung function improvement in men and women. There is an urgent need to recognize the increasing burden of COPD in women and therefore to facilitate global improvements in disease management (smoking cessation, pulmonary rehabilitation…) in half of the population. Nevertheless, important limitations to the treatment of women with COPD include greater under-diagnosis than in men, fewer spirometry tests and medical consultations. In conclusion there is an urgent need to recognize the increasing burden of COPD in women and therefore to facilitate globally improvements in disease management in this specific population.

Solid Fuel Exposure and Chronic Obstructive Pulmonary Disease in Never-Smokers

Background: Chronic obstructive pulmonary disease (COPD) is a public health challenge globally. The burden of COPD is high in never-smokers but little is known about its causes. We aimed to find the prevalence and correlates of COPD in never-smokers, with a special focus on solid fuel exposure.

Methods: We conducted a cross-sectional study in Western China. COPD was defined by FEV1/FVC < lower limits of normal (LLN). Descriptive statistics and multivariable logistic regression were used for analyses.

Results: Six thousand two hundred and seventy one patients were enrolled between June 2015 and August 2016. The prevalence of COPD in never-smokers was 15.0% (95% confidence interval 14.1–15.9). The common independent predictors of COPD in never-smokers included age ≥60 years, exposure to solid fuel, living in a rural area and a history of tuberculosis. Participants with solid fuel exposure were 69% more likely to have COPD (adjusted odds ratio 1.69, 95% CI 1.41–2.04) than those without such exposure. In addition, we found a positive association between small airway dysfunction and solid fuel exposure (OR 1.35, 95% CI 1.18–1.53).

Conclusions: This study confirmed the substantial burden of COPD among never-smokers and also defined the risk factors for COPD in never-smokers. Furthermore, we found a positive association between solid fuel exposure and COPD or small airway dysfunction.

Discriminative Accuracy of Chronic Obstructive Pulmonary Disease Screening Instruments in 3 Low- and Middle-Income Country Settings

IMPORTANCE

Most of the global morbidity and mortality in chronic obstructive pulmonary disease (COPD) occurs in low- and middle-income countries (LMICs), with significant economic effects.

OBJECTIVE

To assess the discriminative accuracy of 3 instruments using questionnaires and peak expiratory flow (PEF) to screen for COPD in 3 LMIC settings.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional analysis of discriminative accuracy, conducted between January 2018 and March 2020 in semiurban Bhaktapur, Nepal; urban Lima, Peru; and rural Nakaseke, Uganda, using a random age- and sex-stratified sample of the population 40 years or older.

EXPOSURES

Three screening tools, the COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE; range, 0-6; high risk indicated by a score of 5 or more or score 2-5 with low PEF [<250 L/min for females and <350 L/min for males]), the COPD in LMICs Assessment questionnaire (COLA-6; range, 0-5; high risk indicated by a score of 4 or more), and the Lung Function Questionnaire (LFQ; range, 0-25; high risk indicated by a score of 18 or less) were assessed against a reference standard diagnosis of COPD using quality-assured postbronchodilator spirometry. CAPTURE and COLA-6 include a measure of PEF.

MAIN OUTCOMES AND MEASURES

The primary outcome was discriminative accuracy of the tools in identifying COPD as measured by area under receiver operating characteristic curves (AUCs) with 95% CIs. Secondary outcomes included sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

Among 10 709 adults who consented to participate in the study (mean age, 56.3 years (SD, 11.7); 50% female), 35% had ever smoked, and 30% were currently exposed to biomass smoke. The unweighted prevalence of COPD at the 3 sites was 18.2% (642/3534 participants) in Nepal, 2.7% (97/3550) in Peru, and 7.4% (264/3580) in Uganda. Among 1000 COPD cases, 49.3% had clinically important disease (Global Initiative for Chronic Obstructive Lung Disease classification B-D), 16.4% had severe or very severe airflow obstruction (forced expiratory volume in 1 second <50% predicted), and 95.3% of cases were previously undiagnosed. The AUC for the screening instruments ranged from 0.717 (95% CI, 0.677-0.774) for LFQ in Peru to 0.791 (95% CI, 0.770-0.809) for COLA-6 in Nepal. The sensitivity ranged from 34.8% (95% CI, 25.3%-45.2%) for COLA-6 in Nepal to 64.2% (95% CI, 60.3%-67.9%) for CAPTURE in Nepal. The mean time to administer the instruments was 7.6 minutes (SD 1.11), and data completeness was 99.5%.

CONCLUSIONS AND RELEVANCE

This study demonstrated that screening instruments for COPD were feasible to administer in 3 low- and middle-income settings. Further research is needed to assess instrument performance in other low- and middle-income settings and to determine whether implementation is associated with improved clinical outcomes.

The burden of chronic obstructive pulmonary disease and its attributable risk factors in the Middle East and North Africa region, 1990–2019

Background

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease that is characterised by persistent respiratory symptoms and airflow limitation. The present study reported the burden of COPD, and its attributable risk factors, in the Middle East and North Africa (MENA) region between 1990 and 2019, by age, sex and socio-demographic index (SDI).

Methods

Data from the Global Burden of Disease (GBD) 2019 study were used to report the burden of COPD in the MENA countries. The prevalence, deaths, and disability-adjusted life-years (DALYs) were presented as counts and age-standardised rates per 100,000 population, with their associated 95% uncertainty intervals (UIs).

Results

In 2019, the regional age-standardised point prevalence and rates of death due to COPD were 2333.9 (2230.1, 2443.6) and 26.1 (22.2, 29.5) per 100,000, which represent a 30.6% (28.2%, 33.0%) increase and an 18.0% (2.8%, 30.9%) decrease, respectively, since 1990. The regional age-standardised DALY rate in 2019 was 649.1 (574.6, 717.7) per 100,000, which had decreased by 11.8% (0.9%, 21.1%) since 1990. Turkey had the highest age-standardised point prevalence in 2019 [3287.1 (3187.4, 3380.3)], while Afghanistan had the highest age-standardised death [40.4 (24.2, 52.6)] and DALY [964.5 (681.8, 1203.2)] rates. The regional age-standardised point prevalence, death and DALY rates in 2019 increased with advancing age and were higher in males in almost all age groups. There was a U-shaped association between SDI and the burden of COPD over the period 1990 to 2019. Moreover, in 2019 smoking (43.7%), ambient particulate matter pollution (22.8%) and occupational particulate matter (11.4%) had the largest proportion of attributable DALYs for both sexes.

Conclusions

COPD is one of the leading causes of death and disability in the MENA region, although the age-standardised burden has decreased over the last 30 years. Nevertheless, COPD accounted for a substantial number of deaths and DALYs, especially among the elderly. Programs targeting risk factors, like smoking, should be taken into consideration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02242-z.

Sex and gender in interstitial lung diseases

Sex and gender differences influence key domains of research, lung health, healthcare access and healthcare delivery. In interstitial lung diseases (ILDs), mouse models of pulmonary fibrosis are clearly influenced by sex hormones. Additionally, short telomeres, a biomarker of telomere regulation gene mutations, are impacted by sex, while heritability unexplained by genetic variation may be attributable to gendered environmental factors that drive epigenetic control. Diseases like idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, occupational ILDs, connective tissue-associated ILDs and lymphangioleiomyomatosis have different prevalence and prognosis between men and women. These differences arise from a complex interplay between biological sex and sociocultural gender influencing genetics, epigenomic modifiers, hormones, immune function, response to treatment and interaction with healthcare systems. Much work remains to be done to systematically integrate sex and gender analysis into relevant domains of science and clinical care in ILD, from strategic considerations for establishing research priorities to guidelines for establishing best clinical practices. Accounting for sex and gender in ILD is essential to the practice of individualised, patient-centred medicine.

Do improved biomass cookstove interventions improve indoor air quality and blood pressure? A systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis evaluates the most recent evidence to examine whether use of improved biomass cookstoves in households in low-middle income countries results in reduction in mean concentrations of carbon monoxide (CO) and particulate matter of size 2.5 μm (PM_2.5) in the cooking area, as well as reduction in mean systolic (SBP) and diastolic blood pressure (DBP) of adults using the cookstoves when compared to adults who use traditional three stone fire or traditional biomass cookstoves.

METHODS

We searched databases of scientific and grey literature. We included studies if published between January 2012 and June 2021, reported impact of ICS interventions in non-pregnant adults in low/middle-income countries, and reported post-intervention results along with baseline of traditional cookstoves. Outcomes included 24- or 48-h averages of kitchen area PM_2.5, CO, mean SBP and DBP. Meta-analyses estimated weighted mean differences between baseline and post-intervention values for all outcome measures.

RESULTS

Eleven studies were included; ten contributed estimates for HAP and four for BP. Interventions lead to significant reductions in PM_2.5 (-0.73 mg/m³, 95% CI: -1.33, -0.13), CO (-8.37 ppm, 95%CI: -13.20, -3.54) and SBP (-2.82 mmHg, 95% CI: -5.53, -0.11); and a non-significant reduction in DBP (-0.80 mmHg, 95%CI: -2.33, 0.73), when compared to baseline of traditional cookstoves. Except for DBP, greatest reductions in all outcomes came from standard combustion ICS with a chimney, compared to ICS without a chimney and advanced combustion ICS.

CONCLUSION

Among the reviewed biomass stove types, ICS with a chimney feature resulted in greatest reductions in HAP and BP.

Previous tuberculosis disease as a risk factor for chronic obstructive pulmonary disease: a cross-sectional analysis of multicountry, population-based studies

BACKGROUND

Risk factors for COPD in high-income settings are well understood; however, less attention has been paid to contributors of COPD in low-income and middle-income countries (LMICs) such as pulmonary tuberculosis. We sought to study the association between previous tuberculosis disease and COPD by using pooled population-based cross-sectional data in 13 geographically diverse, low-resource settings.

METHODS

We pooled six cohorts in 13 different LMIC settings, 6 countries and 3 continents to study the relationship between self-reported previous tuberculosis disease and lung function outcomes including COPD (defined as a postbronchodilator forced expiratory volume in one second (FEV₁)/forced vital capacity (FVC) below the lower limit of normal). Multivariable regressions with random effects were used to examine the association between previous tuberculosis disease and lung function outcomes.

RESULTS

We analysed data for 12 396 participants (median age 54.0 years, 51.5% male); 332 (2.7%) of the participants had previous tuberculosis disease. Overall prevalence of COPD was 8.8% (range 1.7%-15.5% across sites). COPD was four times more common among those with previous tuberculosis disease (25.7% vs 8.3% without previous tuberculosis disease, p<0.001). The adjusted odds of having COPD was 3.78 times higher (95% CI 2.87 to 4.98) for participants with previous tuberculosis disease than those without a history of tuberculosis disease. The attributable fraction of COPD due to previous tuberculosis disease in the study sample was 6.9% (95% CI 4.8% to 9.6%). Participants with previous tuberculosis disease also had lower prebronchodilator Z-scores for FEV₁ (-0.70, 95% CI -0.84 to -0.55), FVC (-0.44, 95% CI -0.59 to -0.29) and the FEV₁:FVC ratio (-0.63, 95% CI -0.76 to -0.51) when compared with those without previous tuberculosis disease.

CONCLUSIONS

Previous tuberculosis disease is a significant and under-recognised risk factor for COPD and poor lung function in LMICs. Better tuberculosis control will also likely reduce the global burden of COPD.

The rural Uganda non-communicable disease (RUNCD) study: prevalence and risk factors of self-reported NCDs from a cross sectional survey

Background

Non-communicable diseases (NCDs) are an increasing global concern, with morbidity and mortality largely occurring in low- and middle-income settings. We established the prospective Rural Uganda Non-Communicable Disease (RUNCD) cohort to longitudinally characterize the NCD prevalence, progression, and complications in rural Africa.

Methods

We conducted a population-based census for NCD research. We systematically enrolled adults in each household among three sub-counties of the larger Nakaseke Health district and collected baseline demographic, health status, and self-reported chronic disease information. We present our data on self-reported chronic disease, as stratified by age, sex, educational attainment, and sub-county.

Results

A total of 16,694 adults were surveyed with 10,563 (63%) respondents enrolled in the self-reported study. Average age was 37.8 years (SD = 16.5) and 45% (7481) were male. Among self-reported diseases, hypertension (HTN) was most prevalent (6.3%). 1.1% of participants reported a diagnosis of diabetes, 1.1% asthma, 0.7% COPD, and 0.4% kidney disease. 2.4% of the population described more than one NCD. Self-reported HTN was significantly higher in the peri-urban subcounty than in the other two rural sub-counties (p < 0.001); diagnoses for all other diseases did not differ significantly between sub-counties. Odds for self-reported HTN increased significantly with age (OR = 1.87 per 10 years of age, 95% CI 1.78–1.96). Male sex was associated with lower odds of reporting asthma (OR = 0.53, 95% CI 0.34–0.82) or HTN (OR = 0.31, 95% CI 0.26–0.40).

Conclusions

The RUNCD will establish one of the largest NCD patient cohorts in rural Africa. First analysis highlights the feasibility of systematically enrolling large numbers of adults living in a rural Ugandan district. In addition, our study demonstrates low levels of self-reported NCDs compared to the nation-wide established levels, emphasizing the need to better educate, characterize, and care for the majority of rural communities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12123-7.

Energy poverty influences urban outdoor air pollution levels during COVID-19 lockdown in south-central Chile

The effect of COVID-19 lockdowns on ambient air pollution levels in urban south-central Chile, where outdoor air pollution primarily originates indoors from wood burning for heating, may differ from trends in cities where transportation and industrial emission sources dominate. This quasi-experimental study compared hourly fine (PM_2.5) and coarse (PM₁₀) particulate matter measurements from six air monitors (three beta attenuation monitors; three low-cost sensors) in commercial and low/middle-income residential areas of Temuco, Chile between 2019 and 2020. The potential impact of varying annual meterological conditions on air quality was also assessed. During COVID-19 lockdown, average monthly ambient PM_2.5 concentrations in a commercial and middle-income residential neighborhood of Temuco were up to 50% higher (from 12 to 18 μg/m³) and 59% higher (from 22 to 35 μg/m³) than 2019 levels, respectively. Conversely, PM_2.5 levels decreased by up to 52% (from 43 to 21 μg/m³) in low-income areas. The fine fraction of PM₁₀ in April 2020 was 48% higher than in April 2017-2019 (from 50% to 74%) in a commercial area. These changes did not appear to result from meterological differences between years. During COVID-19 lockdown, higher outdoor PM_2.5 pollution from wood heating existed in more affluent areas of Temuco, while PM_2.5 concentrations declined among poorer households refraining from wood heating. To reduce air pollution and energy poverty in south-central Chile, affordability of clean heating fuels (e.g. electricity) should be a policy priority.