Association of hospital admission for bronchiectasis with air pollution: A province-wide time-series study in southern China

Exacerbations of bronchiectasis

Bronchiectasis presents a significant challenge due to its rising prevalence, associated economic burden and clinical heterogeneity. This review synthesises contemporary understanding and literature of bronchiectasis exacerbations, addressing the transition from stable state to exacerbations, underlining the importance of early and precise recognition, rigorous severity assessment, prompt treatment, and prevention measures, as well as emphasising the need for strategies to assess and improve early and long-term patient outcomes. The review highlights the interplay between stable state phases and exacerbations in bronchiectasis, introducing the concept of "exogenous and endogenous changes in airways homeostasis" and the "adapted island model" with a particular focus on "frequent exacerbators", a group of patients associated with specific clinical characteristics and worse outcomes. The pathophysiology of exacerbations is explored through the lens of microbial and nonmicrobial triggers and the presence and the activity of comorbidities, elaborating on the impact of both exogenous insults, such as infections and pollution, and endogenous factors such as inflammatory endotypes. Finally, the review proposes a multidisciplinary approach to care, integrating advancements in precision medicine and biomarker research, paving the way for tailored treatments that challenge the traditional antibiotic paradigm.

Bronchiectasis in Asia: a review of current status and challenges

Recent bronchiectasis studies from large-scale multinational, multicentre registries have demonstrated that the characteristics of the disease vary according to geographic region. However, most perspectives on bronchiectasis are dominated by data from Western countries. This review intends to provide an Asian perspective on the disease, focusing on the established registries in India, Korea and China. Asian patients with bronchiectasis are less likely to show female predominance and experience exacerbations, are more likely to be younger, have milder disease, and have fewer options for guideline-recommended treatment than those living in other global regions. Furthermore, Asian bronchiectasis patients demonstrate different comorbidities, microbiological profiles and unique endophenotypes, including post-tuberculosis and dry bronchiectasis. Notably, each Asian region reveals further geographic variations and inter-patient differences. Future studies are warranted to better characterise Asian patients with bronchiectasis.

Interannual evolution of the chemical composition, sources and processes of PM2.5 in Chengdu, China: Insights from observations in four winters

The air quality in China has improved significantly in the last decade and, correspondingly, the characteristics of PM2.5 have also changed. We studied the interannual variation of PM2.5 in Chengdu, one of the most heavily polluted megacities in southwest China, during the most polluted season (winter). Our results show that the mass concentrations of PM2.5 decreased significantly year-by-year, from 195.8 ± 91.0 µg/m3 in winter 2016 to 96.1 ± 39.3 µg/m3 in winter 2020. The mass concentrations of organic matter (OM), SO42-, NH4+ and NO3- decreased by 49.6%, 57.1%, 49.7% and 28.7%, respectively. The differential reduction in the concentrations of chemical components increased the contributions from secondary organic carbon and NO3- and there was a larger contribution from mobile sources. The contribution of OM and NO3- not only increased with increasing levels of pollution, but also increased year-by-year at the same level of pollution. Four sources of PM2.5 were identified: combustion sources, vehicular emissions, dust and secondary aerosols. Secondary aerosols made the highest contribution and increased year-by-year, from 40.6% in winter 2016 to 46.3% in winter 2020. By contrast, the contribution from combustion sources decreased from 14.4% to 8.7%. Our results show the effectiveness of earlier pollution reduction policies and emphasizes that priority should be given to key pollutants (e.g., OM and NO3-) and sources (secondary aerosols and vehicular emissions) in future policies for the reduction of pollution in Chengdu during the winter months.

Sociodemographic correlates with prevalence of comorbidities in patients with chronic obstructive pulmonary disease: a study from a Chinese National Survey

Background

An increase in the prevalence of comorbidities has been reported in patients with chronic obstructive pulmonary disease (COPD). However, contemporary estimates of the overall prevalence of the sociodemographic correlates of COPD comorbidities are scarce and inconsistent in China. This study aimed to investigate the prevalence of sociodemographic correlates of comorbidities in patients with COPD across China.

Methods

This was a cross-sectional study. We used data from the Enjoying Breathing Program between May 2020 and April 2022. Participants with COPD from 17 provinces (or equivalent) were included. Comorbidity clusters were stratified based on the number of comorbidities per person. Univariable and multivariable analyses were used to determine the sociodemographic associations of patients with COPD with specific clusters of comorbidities after adjusting for age, sex, and other prespecified covariates. Tetrachoric correlation analyses were performed to determine the associations between specific comorbidities.

Findings

A total of 3913 participants with COPD were included, of whom 1744 (44.7%) had at least one comorbidity; 25.4% had one comorbid disease, 12.9% had two, and 6.4% had three or more concurrent diseases. The most common comorbidities were hypertension (17.8%), asthma (9.9%), bronchiectasis (8.2%), diabetes (8.2%), and coronary artery disease (7.7%). In the logistic regression models adjusted for a broad set of factors, patients with COPD residing in the east region of China and having health insurance experienced a decreased likelihood of comorbidities (from OR = 0.70 [95% confidence interval [CI], 0.53-0.93] to OR = 0.50 [95% CI, 0.25-0.99]). However, patients over 80 years had increased risk (OR 1.43 [95% CI 1.01-2.03]), as did those in all Modified Medical Research Council (mMRC) grade categories (grade 1: OR = 1.30 [95% CI, 1.02-1.65]; grade 2: OR = 1.39 [95% CI, 1.07-1.8]; grade 3: OR = 1.67 [95% CI, 1.23-2.26]; and grade 4: OR = 1.81 [95% CI, 1.00-3.28]) and in Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2 classification (OR = 1.30 [95% CI, 1.03-1.65]) relative to their respective references. The associations observed in these subgroups were consistent regardless of the number of comorbidities per person. Tetrachoric correlations demonstrated negative associations in pairwise comparisons of the top five comorbidities, ranging from -0.03 to -0.31 (p < 0.001 in all groups).

Interpretation

In China, comorbidities are highly prevalent among patients with COPD, with older age, higher mMRC grade, and lung function decline being the major risk factors. Studies with larger sample sizes are required to elucidate the complex mechanisms underlying COPD comorbidities.

Funding

This study was funded by CAMS Innovation Fund for Medical Sciences (CIFMS) (2021-I2M-1-049 and 2022-I2M-C&T-B-107).

Double trouble: The interaction of PM2.5 and O3 on respiratory hospital admissions

The co-occurrence of fine particulate matter (PM2.5) and ozone (O3) pollution during the warm season has become a growing public health concern. The interaction between PM2.5 and O3 and its contribution to disease burden associated with co-pollution has not been thoroughly examined. We collected data on hospital admissions for respiratory diseases from a city-wide hospital discharge database in Beijing between 2013 and 2019. City-wide 24-h mean PM2.5 and daily maximum 8-h mean O3 were averaged from 35 monitoring stations across Beijing. Conditional Poisson regression was employed to estimate the interaction between warm-season PM2.5 and O3 on respiratory admissions. A model incorporating a tensor product term was used to fit the non-linear interaction and estimate the number of respiratory admissions attributable to PM2.5 and O3 pollution. From January 18, 2013 to December 31, 2019, 1,191,308 respiratory admissions were recorded. We observed multiplicative interactions between warm-season PM2.5 and O3 on upper respiratory infections (P = 0.004), pneumonia (P = 0.002), chronic obstructive pulmonary disease (P = 0.041), and total respiratory disease (P < 0.001). PM2.5-O3 co-pollution during warm season exhibited a super-additive effect on respiratory admissions, with a relative excess risk due to interaction of 1.65% (95%CI: 0.46%-2.84%). There was a non-linear pattern of the synergistic effect between PM2.5 and O3 on respiratory admissions. Based on the World Health Organization global air quality guidelines, 12,421 respiratory admissions would be reduced if both daily PM2.5 and O3 concentrations had not exceeded the target (PM2.5 15 μg/m3, O3 100 μg/m3). The number of respiratory admissions attributable to either PM2.5 or O3 pollution decreased by 48.7% from 2013 to 2019. Prioritizing O3 control during the warm season is a cost-effective strategy for Beijing. These findings underscore the significance of concurrently addressing both PM2.5 pollution and O3 pollution during the warm season to alleviate the burden of respiratory diseases.

Incidence of community-acquired pneumonia hospitalisation in persons with bronchiectasis during the COVID-19 lockdown in Denmark: a retrospective cohort study

BACKGROUND

Persons with bronchiectasis have a high risk of community-acquired pneumonia. Social distancing measures, implemented to prevent the spreading of SARS-CoV-2, could potentially reduce the incidence of other infectious diseases.

RESEARCH QUESTION

Was the COVID-19 lockdown period, along with accompanying social distancing measures, associated with reduced hospital admissions for community-acquired pneumonia and decreased overall mortality rates among individuals with bronchiectasis?

METHODS

Social distancing measures were introduced in Denmark by 12 March 2020 and were preserved until 20 May 2020 (social distancing period), after which the measures were gradually dismissed. The study included all adults (≥18 years) with bronchiectasis residing in Denmark. Confirmed cases of SARS-CoV-2 infection were excluded. We retrospectively investigated the incidence of community-acquired pneumonia hospital admission, death of all causes and respiratory antibiotic treatment in the 10-week social distancing period in 2020, compared with the same dates in 2019. 9344 persons were included in the study.

RESULTS

In the social distancing period, the incidence rate of pneumonia-hospitalisation per 10 000 person-weeks was 9.2 compared with 13.8 in the reference period. This reduction corresponds to an incidence rate ratio (IRR) of 0.67 (95% CI 0.51 to 0.88, p<0.01). Mortality was unchanged (IRR 0.90, 95% CI 0.61 to 1.32, p=0.58). Fewer persons received respiratory antibiotics (IRR 0.85, 95% CI 0.78 to 0.94, p<0.001).

CONCLUSION

The social distancing period was associated with a lower incidence of community-acquired pneumonia hospitalisations and respiratory antibiotic treatments in persons with bronchiectasis while all-cause mortality remained unchanged.

Impact of air pollution on healthcare utilization in patients with bronchiectasis

Introduction

Air pollutants are increasingly recognized to affect long-term outcomes in patients with bronchiectasis. We aimed to figure out the association between air pollutants and the risk of healthcare utilization in patients with bronchiectasis.

Methods

Data for 1,029 subjects with bronchiectasis in Seoul were extracted. The air pollutants included particulate matter of 10 μm or less in diameter (PM10), particulate matter of 2.5 μm or less in diameter (PM2.5), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and nitrogen dioxide (NO2). The outcome was all-cause healthcare uses, defined as outpatient visit, emergency department visit, or hospitalization. The concentration-response curves between each air pollutant and relative risks for healthcare utilization were obtained.

Results

There were significant correlations between air pollutant concentrations and the risk of healthcare utilization, particularly for PM10, NO2, SO2, and CO. This risk was observed even at concentrations below the recommended safe thresholds for the general population. The slopes for the association between PM10 and NO2 and the risk of healthcare use showed a logarithmic growth pattern, with the steepest increase up to 30 μg/m3 and 0.030 parts per million (ppm), respectively. The curves for SO2 and CO showed an inverted U-shaped pattern, with a peak at 0.0045 ppm and a slow upward curve, respectively. No specific trends were observed for PM2.5 and O3 and the risk of healthcare use.

Discussion

Increased concentrations of PM10, NO2, SO2, and CO were associated with increased healthcare utilization in patients with bronchiectasis. For patients with bronchiectasis, there were no safety thresholds for those air pollutants, and even low levels of air pollutant exposure can negatively impact bronchiectasis outcomes.

Validation of diagnostic coding for bronchiectasis in an electronic health record system in Hong Kong

BACKGROUND AND OBJECTIVE

Electronic medical record (EMR) databases can facilitate epidemiology research in various diseases including bronchiectasis. Given the diagnostic challenges of bronchiectasis, the validity of the coding in EMR requires clarification. We aimed to assess the validity of International Classification of Diseases, 9th Revision (ICD-9) code algorithms for identifying bronchiectasis in the territory-wide electronic medical health record system of Clinical Data Analysis and Reporting System (CDARS) in Hong Kong.

MATERIALS AND METHODS

Adult patients who had the diagnosis of bronchiectasis input from Queen Mary Hospital in 2011-2020 were identified using the ICD-9 code of 494 by CDARS. All patients who had high resolution computed tomography (HRCT) were reviewed by respiratory specialists to confirm the presence of bronchiectasis on HRCT.

RESULTS

A total of 19 617 patients who had the diagnostic code of bronchiectasis among all public hospitals in Hong Kong and 1866 in Queen Mary Hospital in the same period. Six hundred and forty-eight cases were randomly selected and validated using medical record and HRCT review by a respiratory specialist. The overall positive predictive value (PPV) was 92.7% (95% CI 90.7-94.7).

CONCLUSIONS

This was the first ICD-9 coding validation for bronchiectasis in Hong Kong CDARS. Our study demonstrated that using ICD-9 code of 494 was reliable to support utility of CDARS database for further clinical research on bronchiectasis.

Short-term association of CO and NO2 with hospital visits for glomerulonephritis in Hefei, China: a time series study

Objective

Recent studies suggest air pollution as an underlying factor to kidney disease. However, there is still limited knowledge about the short-term correlation between glomerulonephritis (GN) and air pollution. Thus, we aim to fill this research gap by investigating the short-term correlation between GN clinical visits and air pollution exposure.

Methods

Between 2015 and 2019, daily GN visit data from two grade A tertiary hospitals in Hefei City were collected, along with corresponding air pollution and meteorological data. A generalized linear model integrated with a distributed lag nonlinear model was employed to analyze the relationship between GN visits and air pollutants. Moreover, we incorporated a dual pollutant model to account for the combined effects of multiple pollutants. Furthermore, subgroup analyses were performed to identify vulnerable populations based on gender, age, and season.

Results

The association between 23,475 GN visits and air pollutants was assessed, and significant positive associations were found between CO and NO2 exposure and GN visit risk. The single-day lagged effect model for CO showed increased risks for GN visits from lag0 (RR: 1.129, 95% CI: 1.031-1.236) to lag2 (RR: 1.034, 95% CI: 1.011-1.022), with the highest risk at lag0. In contrast, NO2 displayed a more persistent impact (lag1-lag4) on GN visit risk, peaking at lag2 (RR: 1.017, 95% CI: 1.011-1.022). Within the dual-pollutant model, the significance persisted for both CO and NO2 after adjusting for each other. Subgroup analyses showed that the cumulative harm of CO was greater in the cold-season and older adult groups. Meanwhile, the female group was more vulnerable to the harmful effects of cumulative exposure to NO2.

Conclusion

Our study indicated that CO and NO2 exposure can raise the risk of GN visits, and female and older adult populations exhibited greater susceptibility.

Use of symptom diary in primary students: association of nitrogen dioxide with prevalence of symptoms

Air pollution is a global public health concern, and numerous studies have attempted to identify the health effects of air pollutants, including nitrogen dioxide (NO₂). In China, there are few studies investigating the relationship between NO₂ exposure and symptoms among children at an individual level. The aim of the study was to evaluate the acute effects of NO₂ on prevalence of symptoms of primary students. An environmental and health questionnaire survey was administered to 4240 primary students in seven districts of Shanghai. Daily symptoms, as well as the daily air pollution and meteorological data from each community, were recorded during the corresponding period. A multivariable logistic regression model was utilized to analyze the relationship between the prevalence of symptoms and NO₂ exposure in school-age children. A model with interaction items was adopted to estimate the interactive effects of NO₂ and confounding factors on symptoms. The average NO₂ level in central urban, industrial and rural areas were 62.07 ± 21.66, 54.86 ± 18.32 and 36.62 ± 21.23 μg m^-3, respectively. Our findings demonstrate that the occurrence of symptoms was significantly affected by NO₂ exposure in the short-term. The largest associations were observed for a 10 μg m^-3 increase in 5-day moving average (lag04) NO₂ concentration with prevalence of general symptoms (odds ratio [OR] = 1.15, 95% confidence interval [95% CI]: 1.07-1.22), throat symptoms (OR = 1.23, 95% CI: 1.13-1.35) and nasal symptoms (OR = 1.142, 95% CI: 1.02-1.27). Subgroup analysis showed that non-rural areas, boys, nearby environmental pollution source and history of present illness were all susceptible factors to the effects of NO₂ exposure. Furthermore, there were interactive effects between NO₂ exposure and area types on reported symptoms. NO₂ can increase the risk of symptoms in primary students in the short-term, which could be significantly enhanced in central urban and industrial areas.

Association between air pollution and hospital admissions for chronic respiratory disease in people aged over 65 years: a time series analysis in Ningbo, China, 2015-2017

PURPOSE

To provide essential information of environmental triggers leading to CRD.

METHODS

We investigated the short-term effects of ambient air pollutants on CRD-related hospitalizations in people aged ≥ 65 years in Ningbo. Data on 23,610 cases of CRD requiring hospitalization were collected from January 2015 to August 2017. After adjusting for temporal trends, seasonality, meteorological conditions, day of week (DOW), and public holidays, we used generalized additive Poisson distribution models to calculate the excess risks (ERs) and 95% confidence intervals (95% CIs) of CRD related hospitalizations.

RESULTS

Our results showed that fine particulate matter (PM_2.5), inhalable particulate matter (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO) were associated with CRD-related hospitalizations in people aged ≥ 65 years. We observed that each 10 μg/m³ increase (except for each 0.1 mg/m³ increase in CO) in the concentration of air pollutants, the percentage of CRD-related hospitalizations due to PM_2.5, PM₁₀, and SO₂ exposure at lag 07, NO₂ exposure at lag 03, and CO exposure at lag 0 increased by 2.13% (95% CI: 0.55%, 3.74%), 1.76% (95% CI: 0.70%, 2.83%), 8.24% (95% CI: 0.92%, 16.09%), 2.16% (95% CI: 0.26%, 4.05%), and 1.19% (95% CI: 0.26%, 2.12%), respectively. In addition, we found stronger effects of particulate matter in 75-84 years age group, on warmer days, and in asthmatics.

CONCLUSION

In conclusion, air pollution may have adverse effects on CRD-related hospitalizations among people aged ≥ 65 years in Ningbo. Therefore, public health measures should be taken to improve air quality.

Modelling of Temperature-Attributable Mortality among the Elderly in Lisbon Metropolitan Area, Portugal: A Contribution to Local Strategy for Effective Prevention Plans

Epidemiological studies on the impact of determining environmental factors on human health have proved that temperature extremes and variability constitute mortality risk factors. However, few studies focus specifically on susceptible individuals living in Portuguese urban areas. This study aimed to estimate and assess the health burden of temperature-attributable mortality among age groups (0-64 years; 65-74 years; 75-84 years; and 85+ years) in Lisbon Metropolitan Area, from 1986-2015. Non-linear and delayed exposure-lag-response relationships between temperature and mortality were fitted with a distributed lag non-linear model (DLNM). In general, the adverse effects of cold and hot temperatures on mortality were greater in the older age groups, presenting a higher risk during the winter season. We found that, for all ages, 10.7% (95% CI: 9.3-12.1%) deaths were attributed to cold temperatures in the winter, and mostly due to moderately cold temperatures, 7.0% (95% CI: 6.2-7.8%), against extremely cold temperatures, 1.4% (95% CI: 0.9-1.8%). When stratified by age, people aged 85+ years were more burdened by cold temperatures (13.8%, 95% CI: 11.5-16.0%). However, for all ages, 5.6% of deaths (95% CI: 2.7-8.4%) can be attributed to hot temperatures. It was observed that the proportion of deaths attributed to exposure to extreme heat is higher than moderate heat. As with cold temperatures, people aged 85+ years are the most vulnerable age group to heat, 8.4% (95% CI: 3.9%, 2.7%), and mostly due to extreme heat, 1.3% (95% CI: 0.8-1.8%). These results provide new evidence on the health burdens associated with alert thresholds, and they can be used in early warning systems and adaptation plans.

The Deteriorating Patient: Therapies Including Lung Transplantation

In this review paper, we discuss the characteristics that define severe bronchiectasis and which may lead to deterioration of noncystic fibrosis bronchiectasis. These characteristics were used to establish the current severity scores: bronchiectasis severity index (BSI), FACED, and E-FACED (exacerbation frequency, forced expiratory volume in 1 second, age, colonization, extension and dyspnea score). They can be used to predict mortality, exacerbation rate, hospital admission, and quality of life. Furthermore, there are different treatable traits that contribute to severe bronchiectasis and clinical deterioration. When present, they can be a target of the treatment to stabilize bronchiectasis.One of the first steps in treatment management of bronchiectasis is evaluation of compliance to already prescribed therapy. Several factors can contribute to treatment adherence, but to date no real interventions have been published to ameliorate this phenomenon. In the second step, treatment in deteriorating patients with bronchiectasis should be guided by the predominant symptoms, for example, cough, sputum, difficulty expectoration, exacerbation rate, or physical impairment. In the third step, we evaluate treatable traits that could influence disease severity in the deteriorating patient. Finally, in patients who are difficult to treat despite maximum medical treatment, eligibility for surgery (when disease is localized), should be considered. In case of end-stage disease, the evaluation for lung transplantation should be performed. Noninvasive ventilation can serve as a bridge to lung transplantation in patients with respiratory failure.