Population-based prevalence of bronchiectasis and associated comorbidities in South Korea

Early clinical remission and its role in lung function decline and exacerbation in adult Korean patients with asthma

INTRODUCTION

Despite advancements in asthma management, many patients continue to experience poor disease control, lung function decline, and frequent exacerbations. Clinical remission (CR) has been proposed as a novel treatment target and surrogate marker for long-term outcomes. This study evaluates whether early CR at 1 year after inhaled corticosteroid (ICS) initiation influences lung function decline and exacerbation risk in asthma.

METHODS

This retrospective cohort study evaluated 492 asthma patients treated with ICS at two teaching hospitals. Patients were classified into early CR and non-early CR groups. Early CR was defined based on a composite set of criteria, including sustained absence of exacerbations, no systemic corticosteroid use, symptom control and stable or improved lung function in the first year following ICS initiation. Study outcomes were the annual forced expiratory volume in one second (FEV1) decline and the moderate-to-severe exacerbations.

RESULTS

Early CR was significantly associated with slower annual FEV1 decline (4-component CR, adjusted β=31.6 mL/year, p=0.001; 3-component CR, adjusted β=15.7 mL/year, p=0.043). The benefits of early 4-component CR on attenuating annual FEV1 decline were more pronounced in specific phenotypes, including type-2 high asthma, persistent airflow limitation, severe asthma and patients requiring add-on long-acting muscarinic antagonists. Early 4-component CR had a reduced risk of moderate-to-severe (adjusted HR (aHR)=0.591, p=0.011) and severe exacerbations (aHR=0.508, p=0.025).

CONCLUSIONS

Achieving CR within 1 year of ICS initiation was associated with improved lung function preservation and reduced exacerbation risk. These findings suggest the importance of achieving early CR as a clinical target in asthma management.

Disease Severity and Activity in Bronchiectasis: A Paradigm Shift in Bronchiectasis Management

Bronchiectasis has an increasing prevalence and substantial clinical and economic burden. Therefore, physicians should identify patients with bronchiectasis at high risk of disease progression to ensure optimal management in advance. The heterogeneity of bronchiectasis means it is unlikely that any single parameter could identify highrisk patients; therefore, disease severity is usually assessed using validated composite tools, such as the Bronchiectasis Severity Index, FACED, and Bronchiectasis Aetiology Comorbidity Index, to predict long-term outcomes in bronchiectasis. Disease severity, however, implies an advanced process with lung destruction. Earlier intervention may prevent disease progression and improve outcomes. To identify patients at risk, rather than patients with established advanced disease, we need to shift our focus from disease severity to disease activity. Disease activity denotes the activation level of underlying pathophysiological processes and can be measured using clinical presentations and biomarkers. This review discusses a paradigm shift in bronchiectasis management, focusing on disease activity rather than severity, to prevent disease progression.

Analysis of factors influencing bronchiectasis patients with active pulmonary tuberculosis and development of a nomogram prediction model

Background

To identify the risk factors for bronchiectasis patients with active pulmonary tuberculosis (APTB) and to develop a predictive nomogram model for estimating the risk of APTB in bronchiectasis patients.

Methods

A retrospective cohort study was conducted on 16,750 bronchiectasis patients hospitalized at the Affiliated Hospital of Guangdong Medical University and the Second Affiliated Hospital of Guangdong Medical University between January 2019 and December 2023. The 390 patients with APTB were classified as the case group, while 818 patients were randomly sampled by computer at a 1:20 ratio from the 16,360 patients with other infections to serve as the control group. Relevant indicators potentially leading to APTB in bronchiectasis patients were collected. Patients were categorized into APTB and inactive pulmonary tuberculosis (IPTB) groups based on the presence of tuberculosis. The general characteristics of both groups were compared. Variables were screened using the least absolute shrinkage and selection operator (LASSO) analysis, followed by multivariate logistic regression analysis. A nomogram model was established based on the analysis results. The model's predictive performance was evaluated using calibration curves, C-index, and ROC curves, and internal validation was performed using the bootstrap method.

Results

LASSO analysis identified 28 potential risk factors. Multivariate analysis showed that age, gender, TC, ALB, MCV, FIB, PDW, LYM, hemoptysis, and hypertension are independent risk factors for bronchiectasis patients with APTB (p < 0.05). The nomogram demonstrated strong calibration and discrimination, with a C-index of 0.745 (95% CI: 0.715-0.775) and an AUC of 0.744 for the ROC curve. Internal validation using the bootstrap method produced a C-index of 0.738, further confirming the model's robustness.

Conclusion

The nomogram model, developed using common clinical serological characteristics, holds significant clinical value for assessing the risk of APTB in bronchiectasis patients.

Secondary Immunodeficiency and Non-cystic Fibrosis Bronchiectasis

Bronchiectasis is a chronic respiratory disease characterized by abnormal dilation of the bronchi that causes cough, sputum, and recurrent infections. As it may be associated with various respiratory or systemic diseases, a critical aspect of managing bronchiectasis is to identify the underlying cause. Immunodeficiency is a rare but important cause of bronchiectasis, and its treatability is a significant trait for bronchiectasis management. While primary immunodeficiencies in bronchiectasis are well recognized, secondary immunodeficiencies remain under-reported and under-researched. Secondary immunodeficiencies may result from various diseases and conditions, such as hematologic malignancies, human immunodeficiency virus infection, renal transplantation, or the use of immunosuppressive drugs, and may contribute to the occurrence of bronchiectasis. Recurrent pulmonary and/or extrapulmonary infections in bronchiectasis may indicate the presence of secondary immunodeficiency in patients with these underlying conditions. For treatment, examining the underlying condition, managing bronchiectasis adequately, and prophylactic antibiotics (e.g., macrolide) and/or supplementary immunoglobulin G therapy may provide potential benefits. Considering the projected increase in the prevalence of secondary immunodeficiencies and bronchiectasis, future guidelines and research on the diagnosis and optimized treatment are needed.

Epidemiology of bronchiectasis

Bronchiectasis is a chronic respiratory disease characterised by permanent enlargement of the airways associated with cough, sputum production and a history of pulmonary exacerbations. In the past few years, incidence and prevalence of bronchiectasis have increased worldwide, possibly due to advances in imaging techniques and disease awareness, leading to increased socioeconomic burden and healthcare costs. Consistently, a mortality increase in bronchiectasis patient cohorts has been demonstrated in certain areas of the globe, with mortality rates of 16-24.8% over 4-5 years of follow-up. However, heterogeneity in epidemiological data is consistent, as reported prevalence in the general population ranges from 52.3 to more than 1000 per 100 000. Methodological flaws in the designs of available studies are likely to underestimate the proportion of people suffering from this condition worldwide and comparisons between different areas of the globe might be unreliable due to different assessment methods or local implementation of the same method in different contexts. Differences in disease severity associated with diverse geographical distribution of aetiologies, comorbidities and microbiology might explain an additional quota of heterogeneity. Finally, limited access to care in certain geographical areas is associated with both underestimation of the disease and increased severity and mortality. The aim of this review is to provide a snapshot of available real-world epidemiological data describing incidence and prevalence of bronchiectasis in the general population. Furthermore, data on mortality, healthcare burden and high-risk populations are provided. Finally, an analysis of the geographical distribution of determinants contributing to differences in bronchiectasis epidemiology is offered.

Patient-managed interventions for adults with bronchiectasis: evidence, challenges and prospects

Bronchiectasis is a chronic lung condition which is characterised by recurrent chest infections, chronic sputum production and cough, and limited exercise tolerance. While bronchiectasis may be caused by various aetiologies, these features are shared by most patients with bronchiectasis regardless of the cause. This review consolidates the existing evidence on patient-managed interventions for adults with bronchiectasis, while also outlining areas for future research. Airway clearance techniques and hyperosmolar agents are key components of the bronchiectasis management and consistently recommended for clinical implementation. Questions around their prescription, such as optimal sequence of delivery, are still to be answered. Pulmonary rehabilitation and exercise are also recommended for patients with bronchiectasis. Relatively strong evidence underpins this recommendation during a clinically stable stage of the disease, although the role of pulmonary rehabilitation following an exacerbation is still unclear. Additionally, self-management programmes feature prominently in bronchiectasis treatment, yet the lack of consensus regarding their definition and outcomes presents hurdles to establishing a cohesive evidence base. Moreover, cough, a cardinal symptom of bronchiectasis, warrants closer examination. Although managing cough in bronchiectasis may initially appear risky, further research is necessary to ascertain whether strategies employed in other respiratory conditions can be safely and effectively adapted to bronchiectasis, particularly through identifying patient responder populations and criteria where cough may not enhance airway clearance efficacy and its control is needed. Overall, there is a growing recognition of the importance of patient-managed interventions in the bronchiectasis management. Efforts to improve research methodologies and increase research funding are needed to further advance our understanding of these interventions, and their role in optimising patient care and outcomes.

Prevalence of bronchiectasis in adults: a meta-analysis

BACKGROUND

Bronchiectasis, once considered an orphan disease, is receiving attention globally owing to its increasing prevalence, healthcare burden, and associated morbidity. However, the prevalence of bronchiectasis is unclear. This meta-analysis estimates the prevalence of bronchiectasis in adults, providing a valuable reference for future research.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched from inception to May 31, 2024 for studies reporting the prevalence of bronchiectasis. Study selection, data extraction, and overall analysis of risk of the retrieved studies were conducted independently by two authors. The tool for assessing the risk of bias in prevalence studies was used to evaluate overall risk. Stata software (version 15.1) was used to performed the meta-analysis. Subgroup and sensitivity analyses were conducted to identify the source of heterogeneity. Funnel plots combined with Egger's test were used to detect publication bias.

RESULTS

The pooled prevalence of bronchiectasis in adults from 15 studies covering 437,851,478 individuals was 680 per 100,000 (95% CI: 634-727 per 100,000). Subgroup analysis showed that the prevalence of bronchiectasis in the United States, Korea, and China was 478 per 100,000 (95% CI: 367-588 per 100,000), 886 per 100,000 (95% CI: 778-993 per 100,000), and 759 per 100,000 (95% CI: 35-2399 per 100,000), respectively; 467 per 100,000 (95% CI: 416-518 per 100,000) in males and 535 per 100,000 (95% CI: 477-592 per 100,000) in females; 3958 per 100,000 (95% CI: 117-12637 per 100,000), 4677 per 100,000 (95% CI: 427-8928 per 100,000), and 3630 per 100,000 (95% CI: 158-7103 per 100,000) among never-smokers, ever-smokers, and current smokers, respectively; 430 per 100,000 (95% CI: 411-450 per 100,000), 380 per 100,000 (95% CI: 374-386 per 100,000), and 351 per 100,000 (95% CI: 342-360 per 100,000) among individuals with body mass index<18.5, 18.5-24.9, and ≥ 25, respectively. Sixteen comorbidities were evaluated in patients with bronchiectasis, revealing a high rate.

CONCLUSION

Bronchiectasis is not a rare disease and requires more attention from scientific researchers.

TRIAL REGISTRATION

The protocol for this review was registered with PROSPERO: CRD42023409216. Registered 26 June 2023.

Incidence of bronchiectasis in patients with acromegaly: a cohort study

Objective

Associations between acromegaly and several respiratory diseases, such as obstructive lung disease or sleep apnea, have been suggested, but the relationship between bronchiectasis and acromegaly is unclear. We investigated whether acromegaly is related to the development of bronchiectasis.

Materials and methods

Using the Korean National Health Insurance System database between 2006 and 2016, we studied the relationship between acromegaly and bronchiectasis in patients with acromegaly (n=2593) and controls (1:5 age- and sex-matched subjects without acromegaly, n=12965) with a mean follow-up period of 8.9 years. Cox proportional hazards regression analysis was used to assess the risk of bronchiectasis in patients with acromegaly compared with controls after adjusting for age, sex, household income, place, type 2 diabetes, hypertension, and dyslipidemia.

Results

The mean age of the participants was 47.65 years, and male subjects comprised 45.62% of the cohort. The incidence rate of bronchiectasis in patients with acromegaly was 3.64 per 1,000 person-years and was significantly higher than that in controls (2.47 per 1,000 person-years) (log-rank test p = 0.002). In multivariable Cox proportional hazards regression modeling, the risk of bronchiectasis was significantly higher in patients with acromegaly than that in controls (HR: 1.49; 95% CI: 1.15-1.94, p = 0.0025) after adjusting for age, sex, household income, place, type 2 diabetes, hypertension, and dyslipidemia.

Conclusions

Our results suggest that acromegaly may be associated with bronchiectasis.

Application of the Lancet Commission COPD classification to COPD Cohort Population in South Korea

The Lancet Commissions on COPD recommended a new classification based on five main risk factors. Patients with COPD were prospectively enrolled in a Korean COPD subgroup study cohort between April 2012 and June 2022. Patients were classified according to the etiologies (Type 1: Genetically determined (COPD-G), Type 2: Abnormal lung development (COPD-D), Type 3: Infections (COPD-I), Type 4: Cigarette smoking (COPD-C), Type 5: Biomass and pollution (COPD-P)). The database enrolled 3476 patients. Among 3392 patients, 52 (2 %), 1339 (39 %), 2930 (86 %), and 2221 (65 %) were compatible with type 2 (COPD-D), 3 (COPD-I), 4 (COPD-C), and 5 (COPD-P), respectively. Most patients (71 %, 2405) had multiple risk factors contributing to their COPD. However, 93, 712, and 182 patients had only type 3 (COPD-I), 4 (COPD-C), and 5 (COPD-P), respectively. Type 3 (COPD-I) only patients were significantly younger, more often female, and had lower lung function. Both the rate and frequency of severe exacerbations were significantly higher in type 3 (COPD-I) only patients (p = 0.038 and p = 0.048, respectively). Compared with type 5 (COPD-P) only, type 3 (COPD-I) only was significantly associated with the risk of severe exacerbation (Odds ratio, 5.7 [95 % CI, 1.0-32.4]; P = 0.049, incident rate ratio, 8.7 [95 % CI, 1.7-44.0]; P = 0.009). Many patients were affected by multiple factors. Therefore, it is important to consider not only smoking history, but also other potential risk factors when evaluating patients with COPD. Further research is needed to explore the implications of this new COPD classification system for clinical practice and treatment strategies.

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.

Increased bronchiectasis risk and related risk factors in inflammatory bowel disease: a 10-year Korean national cohort study

Background

The association between inflammatory bowel disease (IBD) and an increased risk of bronchiectasis, as well as contributing factors, remains unclear. Additionally, whether bronchiectasis increases disease burden in IBD remains unknown. Therefore, this study aimed to: 1) assess whether IBD increases the risk of incident bronchiectasis; 2) compare the risk of bronchiectasis between individuals with Crohn's disease (CD) and those with ulcerative colitis (UC); 3) identify risk factors for bronchiectasis in individuals with IBD; and 4) examine the disease burden in individuals with IBD and bronchiectasis versus those without.

Methods

We conducted a population-based matched cohort study involving adults aged ≥20 years with IBD, using data acquired from the Korean National Health Insurance Service-National Sample Cohort database between 2002 and 2012.

Results

During the mean follow-up of 9.6 years, the incidence rate of bronchiectasis was 419.63 out of 100 000 person-years (PY) and 309.65 out of 100 000 PY in the IBD and matched cohorts (adjusted hazard ratio (aHR) 1.21, 95% CI 1.05-1.39), respectively. UC was associated with increased bronchiectasis risk (aHR 1.42, 95% CI 1.19-1.69), but CD was not. Multivariate Cox regression analyses showed that age, male sex, medical aid, underweight status, COPD and diabetes mellitus were associated with an increased risk of bronchiectasis in the IBD cohort (p<0.05). The mortality, emergency department visit and hospitalisation rates were significantly higher for individuals with IBD and bronchiectasis compared with those without bronchiectasis (p<0.05).

Conclusion

IBD is associated with increased risk of bronchiectasis, which results in a greater disease burden in individuals with IBD.

Usefulness of Impulse Oscillometry in Predicting the Severity of Bronchiectasis

BACKGROUND

Bronchiectasis is a chronic respiratory disease that leads to airway inflammation, destruction, and airflow limitation, which reflects its severity. Impulse oscillometry (IOS) is a non-invasive method that uses sound waves to estimate lung function and airway resistance. The aim of this study was to assess the usefulness of IOS in predicting the severity of bronchiectasis.

METHODS

We retrospectively reviewed the IOS parameters and clinical characteristics in 145 patients diagnosed with bronchiectasis between March 2020 and May 2021. Disease severity was evaluated using the FACED score, and patients were divided into mild and moderate/severe groups.

RESULTS

Forty-four patients (30.3%) were in the moderate/severe group, and 101 (69.7%) were in the mild group. Patients with moderate/severe bronchiectasis had a higher airway resistance at 5 Hz (R5), a higher difference between the resistance at 5 and 20 Hz (R5-R20), a higher resonant frequency (Fres), and a higher area of reactance (AX) than patients with mild bronchiectasis. R5 ≥0.43, resistance at 20 Hz (R20) ≥0.234, R5-R20 ≥28.3, AX ≥1.02, reactance at 5 Hz (X5) ≤-0.238, and Fres ≥20.88 revealed significant univariable relationships with bronchiectasis severity (p<0.05). Among these, only X5 ≤-0.238 exhibited a significant multivariable relationship with bronchiectasis severity (p=0.039). The receiver operating characteristic curve for predicting moderate- to-severe bronchiectasis of FACED score based on IOS parameters exhibited an area under the curve of 0.809.

CONCLUSION

The IOS assessed by the disease severity of FACED score can effectively reflect airway resistance and elasticity in bronchiectasis patients and serve as valuable tools for predicting bronchiectasis severity.

A systematic literature review of the clinical and socioeconomic burden of bronchiectasis

BACKGROUND

The overall burden of bronchiectasis on patients and healthcare systems has not been comprehensively described. Here, we present the findings of a systematic literature review that assessed the clinical and socioeconomic burden of bronchiectasis with subanalyses by aetiology (PROSPERO registration: CRD42023404162).

METHODS

Embase, MEDLINE and the Cochrane Library were searched for publications relating to bronchiectasis disease burden (December 2017-December 2022). Journal articles and congress abstracts reporting on observational studies, randomised controlled trials and registry studies were included. Editorials, narrative reviews and systematic literature reviews were included to identify primary studies. PRISMA guidelines were followed.

RESULTS

1585 unique publications were identified, of which 587 full texts were screened and 149 were included. A further 189 citations were included from reference lists of editorials and reviews, resulting in 338 total publications. Commonly reported symptoms and complications included dyspnoea, cough, wheezing, sputum production, haemoptysis and exacerbations. Disease severity across several indices and increased mortality compared with the general population was reported. Bronchiectasis impacted quality of life across several patient-reported outcomes, with patients experiencing fatigue, anxiety and depression. Healthcare resource utilisation was considerable and substantial medical costs related to hospitalisations, treatments and emergency department and outpatient visits were accrued. Indirect costs included sick pay and lost income.

CONCLUSIONS

Bronchiectasis causes significant clinical and socioeconomic burden. Disease-modifying therapies that reduce symptoms, improve quality of life and reduce both healthcare resource utilisation and overall costs are needed. Further systematic analyses of specific aetiologies and paediatric disease may provide more insight into unmet therapeutic needs.

Bronchiectasis management in adults: state of the art and future directions

Formerly regarded as a rare disease, bronchiectasis is increasingly recognised. A renewed interest in this disease has led to significant progress in bronchiectasis research. Randomised clinical trials (RCTs) have demonstrated the benefits of airway clearance techniques, inhaled antibiotics and long-term macrolide therapy in bronchiectasis patients. However, the heterogeneity of bronchiectasis remains one of the most challenging aspects of management. Phenotypes and endotypes of bronchiectasis have been identified to help find "treatable traits" and partially overcome disease complexity. The goals of therapy for bronchiectasis are to reduce the symptom burden, improve quality of life, reduce exacerbations and prevent disease progression. We review the pharmacological and non-pharmacological treatments that can improve mucociliary clearance, reduce airway inflammation and tackle airway infection, the key pathophysiological features of bronchiectasis. There are also promising treatments in development for the management of bronchiectasis, including novel anti-inflammatory therapies. This review provides a critical update on the management of bronchiectasis focusing on treatable traits and recent RCTs.

Impact of Rheumatoid Arthritis and Seropositivity on the Risk of Non-Cystic Fibrosis Bronchiectasis

BACKGROUND

Despite the coexistence of bronchiectasis and rheumatoid arthritis (RA) and the poor prognosis associated with the combination of conditions, to our knowledge, no longitudinal studies that comprehensively evaluated whether patients with RA have a higher risk of bronchiectasis compared with those without RA have been published. Whether seropositivity is associated with an increased risk of bronchiectasis in RA is the subject of ongoing controversy.

RESEARCH QUESTION

Does RA influence the development of bronchiectasis? Is seropositivity associated with an increased risk of bronchiectasis in RA?

STUDY DESIGN AND METHODS

The incidence of bronchiectasis was compared between individuals with RA (n = 50,651; seropositive rheumatoid arthritis [SPRA]: n = 35,879 and seronegative rheumatoid arthritis [SNRA]: n = 14,772) and 1:5 age- and sex-matched control patients (n = 253,255) enrolled between 2010 and 2017 in the Korean National Health Insurance Service database. The participants were followed from 1 year after RA diagnosis or the corresponding index date to the date of bronchiectasis incidence, censored date, or December 2019.

RESULTS

The cumulative incidence of bronchiectasis at 9 years of follow-up was approximately 7% in participants with RA. During a median follow-up of 4.3 years (interquartile range, 2.6-6.3 years), participants with RA showed a 2.12-fold higher risk of developing bronchiectasis than matched control participants, even after adjusting for potential confounders related to bronchiectasis development (95% CI, 2.00-2.25). In an analysis of RA serologic status using a fully adjusted model, participants with SPRA and those with SNRA showed 2.34-fold (95% CI, 2.20-2.49) and 1.56-fold (95% CI, 1.40-1.73) increased risks, respectively, compared with matched control participants.

INTERPRETATION

Individuals with RA had approximately twice the risk of developing bronchiectasis than matched control individuals, even after adjusting for potential confounders. The increased risk was more evident in individuals with SPRA than in those with SNRA, implying that rheumatic inflammation plays a major role in the development of RA-bronchiectasis overlap.

The Impact of Bronchiectasis on the Clinical Characteristics of Non-Severe Asthma

Current literature primarily delves into the relationship between bronchiectasis and severe asthma, and only a few studies have evaluated the impact of bronchiectasis in patients with non-severe asthma. Therefore, this study investigated the clinical impact of bronchiectasis in patients with non-severe asthma. A prospective observational study of 140 non-severe asthmatic patients with (bronchiectasis group) and without bronchiectasis (control group) was conducted between September 2012 and February 2022. The bronchiectasis and control groups were compared in terms of demographics, lung function, asthma control test (ACT) results, exacerbation history, and respiratory medications. Among 140 non-severe asthmatic subjects, approximately 15.7% (n = 22) had bronchiectasis. The most common type of bronchiectasis was cylindrical type (90.7%). The left lingular division was the most frequently involved lung lobe (20.4%). There were no significant differences in the demographics (age, sex, body mass index, smoking history, and comorbidities) or ACT results between the 2 groups. The bronchiectasis group used inhaled corticosteroids/long-acting β2-agonists (P = 0.074) and mucolytics (P < 0.001) more frequently than the control group. Compared to the control group, the bronchiectasis group had lower forced expiratory volume in 1 second (FEV1) (L) (1.9 ± 0.7 L vs. 2.3 ± 0.9 L, P = 0.039) and FEV1%predicted (67.2 ± 22.2%predicted vs. 77.1 ± 20.0%predicted, P = 0.038). The rate of hospital admission to a general ward in the preceding year was significantly higher in the bronchiectasis group compared to those of the control group (23.8% vs. 3.5%, P = 0.005) with an adjusted odds ratio of 6.308 (95% confidence interval, 1.401-28.392). Patients with non-severe asthma and bronchiectasis had lower lung function and more frequent exacerbations requiring hospitalization than those without bronchiectasis. More attention is needed for asthmatic patients with bronchiectasis, even if the asthma is not severe.

A phase 4 multicentre, 2×2 factorial randomised, double-blind, placebo-controlled trial to investigate the efficacy and safety of tobramycin inhalation solution for Pseudomonas aeruginosa eradication in bronchiectasis: ERASE

Chronic Pseudomonas aeruginosa (PA) infection significantly contributes to morbidity and mortality in bronchiectasis patients. Initiating antibiotics early may lead to the eradication of PA. Here we outline the design of a trial (ERASE; NCT06093191) assessing the efficacy and safety of inhaled tobramycin, alone or with oral ciprofloxacin, in bronchiectasis patients with a new isolation of PA. This multicentre, 2×2 factorial randomised, double-blind, placebo-controlled, parallel-group trial includes a 2-week screening period, a 12-week treatment phase (with a combination of ciprofloxacin or a placebo at initial 2 weeks) and a 24-week follow-up. 364 adults with bronchiectasis and a new PA isolation will be randomly assigned to one of four groups: placebo (inhaled saline and ciprofloxacin placebo twice daily), ciprofloxacin alone (750 mg ciprofloxacin and inhaled saline twice daily), inhaled tobramycin alone (inhaled 300 mg tobramycin and ciprofloxacin placebo twice daily) or a combination of both drugs (inhaled 300 mg tobramycin and 750 mg ciprofloxacin twice daily). The primary objective of this study is to assess the proportion of patients successfully eradicating PA in each group by the end of the study. Efficacy will be evaluated based on the eradication rate of PA at other time points (12, 24 and 36 weeks), the occurrence of exacerbations and hospitalisations, time to first pulmonary exacerbations, patient-reported outcomes, symptom measures, pulmonary function tests and the cost of hospitalisations. To date no randomised trial has evaluated the benefit of different PA eradication strategies in bronchiectasis patients. The ERASE trial will therefore generate crucial data to inform future clinical guidelines.

X -linked inheritance of primary ciliary dyskinesia and retinitis pigmentosa due to RPGR variant: A case report and literature review

Bronchiectasis is a chronic respiratory condition characterized by irreversible bronchial dilation, often caused by infection or inflammation. It can be associated with primary ciliary dyskinesia (PCD), a hereditary disorder affecting cilia function in various organs and flagella. PCD's genetic heterogeneity leads to varying disease severity. PCD may be more prevalent in Asia, but its diagnosis is often delayed in Japan. This study reviewed a case of PCD and retinitis pigmentosa (RP) with the relevant literature. The patient had a persistent cough, sputum, and diffuse bronchiectasis. He was diagnosed with a combination of PCD and RP, with the presence of an X-linked retinitis pigmentosa GTPase regulator (RPGR) variant confirmed through electron microscopy, retinal scan, and genetic testing. Although co-occurrence of bronchiectasis and RP is rare, PCD should be considered in cases of persistent wet cough in childhood or unidentified bronchiectasis aetiology. Ophthalmologists should consider concomitant PCD in RP patients.

The Economic Burden of Bronchiectasis: A Systematic Review

BACKGROUND

Bronchiectasis, a previously neglected condition, now has renewed research interest. There are a few systematic reviews that have reported on the economic and societal burden of bronchiectasis in adults, but none have reported on children. We undertook this systematic review to estimate the economic burden of bronchiectasis in children and adults.

RESEARCH QUESTION

What is the health care resource utilization and economic burden of bronchiectasis in adults and children?

STUDY DESIGN AND METHODS

We performed a systematic review identifying publications from Embase, PubMed, Web of Science, Cochrane (trials, reviews, and editorials), and EconLit about the economic burden and health care utilization in adults and children with bronchiectasis between January 1, 2001, and October 10, 2022. We used a narrative synthesis approach and estimated aggregate costs for several countries.

RESULTS

We identified 53 publications reporting on the economic burden and/or health care utilization of people with bronchiectasis. Total annual health care costs per adult patient ranged from 2021 $3,579 to $82,545 USD and were predominantly driven by hospitalization costs. Annual indirect costs including lost income because of illness (reported in only five studies) ranged from $1,311 to $2,898 USD. Total health care costs in children with bronchiectasis were $23,687 USD annually in the one study that estimated them. Additionally, one publication found that children with bronchiectasis missed 12 school days per year. We estimated aggregate annual health care costs for nine countries, ranging from $101.6 million per year in Singapore to $14.68 billion per year in the United States. We also estimated the aggregate cost of bronchiectasis in Australian children to be $17.77 million per year.

INTERPRETATION

This review highlights the substantial economic burden of bronchiectasis for patients and health systems. To our knowledge, it is the first systematic review to include the costs for children with bronchiectasis and their families. Future research to examine the economic impact of bronchiectasis in children and economically disadvantaged communities, and to further understand the indirect burden of bronchiectasis on individuals and the community, is needed.

Systemic sclerosis and risk of bronchiectasis: a nationwide longitudinal cohort study

BACKGROUND

The association between systemic sclerosis and the development of bronchiectasis is unclear. This study aimed to compare the risk of bronchiectasis between individuals with systemic sclerosis and those without using a nationwide longitudinal dataset.

METHODS

Using the Korean National Health Insurance Service dataset between 2010 and 2017, we identified 4845 individuals aged ≥ 20 years with systemic sclerosis and 24,225 without systemic sclerosis who were matched 1:5 by age and sex. They were followed up until the date of a bronchiectasis diagnosis, death, or December 31, 2019, whichever came first.

RESULTS

During a median follow-up period of 6.0 (interquartile range, 3.2-8.7) years, 5.3% of the systemic sclerosis cohort and 1.9% of the matched cohort developed bronchiectasis, with incidence rates of 9.99 and 3.23 per 1000 person-years, respectively. Even after adjusting for potential confounders, the risk of incident bronchiectasis was significantly higher in the systemic sclerosis cohort than in the matched cohort (adjusted hazard ratio 2.63, 95% confidence interval 2.22-3.12). A subgroup analysis of individuals with systemic sclerosis revealed that the risk of incident bronchiectasis was notably higher in younger individuals aged 20-39 years (P for interaction = 0.048) and in those without other coexisting connective tissue diseases (P for interaction = 0.006) than in their counterparts.

CONCLUSIONS

The risk of incident bronchiectasis is higher in individuals with systemic sclerosis than those without. Bronchiectasis should be considered one of the pulmonary manifestations related to systemic sclerosis.

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.

Impact of Allergic Disease on the Risk of Mycobacterial Disease

BACKGROUND

The association between allergic diseases and the risk of mycobacterial disease is unclear.

OBJECTIVE

To evaluate the association between allergic diseases and mycobacterial diseases.

METHODS

This was a population-based cohort study of 3,838,680 individuals, without prior mycobacterial disease, who participated in the 2009 National Health Screening Exam. We evaluated the incidence of mycobacterial disease (tuberculosis or nontuberculous mycobacterial infection) in participants with allergic disease (asthma, allergic rhinitis, or atopic dermatitis) and those without allergic disease. We followed the cohort up until the date of mycobacterial disease diagnosis, follow-up loss, death, or December 2018.

RESULTS

During a median follow-up of 8.3 (interquartile range, 8.1-8.6) years, 0.6% of participants developed mycobacterial disease. The incidence of mycobacterial disease was significantly higher in those with allergic diseases than in those without allergic diseases (1.0 vs 0.7/1000 person-years; P < .001), with an adjusted hazard ratio of 1.13 (95% CI, 1.10-1.17). Asthma (adjusted hazard ratio, 1.37; 95% CI, 1.29-1.45) and allergic rhinitis (adjusted hazard ratio, 1.07; 95% CI, 1.04-1.11) increased the hazard of mycobacterial disease, whereas atopic dermatitis did not. The association between allergic diseases and hazard of mycobacterial disease was more prominent in older (age ≥ 65 years, P for interaction = .012) and obese (body mass index ≥ 25 kg/m2, P for interaction < .001) participants.

CONCLUSION

Allergic diseases including asthma and allergic rhinitis were associated with an increased risk of mycobacterial disease, whereas atopic dermatitis was not.

Advances in pharmacotherapy for bronchiectasis in adults

INTRODUCTION

Bronchiectasis has become a growing concern of chronic airway disease because of the enormous socioeconomic burden. Four cardinal interdependent components - impaired airway defense, recurrent airway infections, inflammatory response, and airway damage, in conjunction with the underlying etiology, have collectively played a role in modulating the vicious vortex of the pathogenesis and progression of bronchiectasis. Current pharmacotherapy aims to target at these aspects to break the vicious vortex.

AREAS COVERED

The authors retrieve and review, in MEDLINE, Web of Science and ClinicalTrials.gov registry, the studies about pharmacotherapy for bronchiectasis from these aspects: antibiotics, mucoactive medications, bronchodilators, anti-inflammatory drug, and etiological treatment.

EXPERT OPINION

Future drug development and clinical trials of bronchiectasis need to pay more attention to the different phenotypes or endotypes of bronchiectasis. There is a need for the development of novel inhaled antibiotics that could reduce bacterial loads, improve quality-of-life, and decrease exacerbation risks. More efforts are needed to explore the next-generation neutrophil-targeted therapeutic drugs that are expected to ameliorate respiratory symptom burden, reduce exacerbation risks, and hinder airway destruction in bronchiectasis.

Epidemiological characteristics of nontuberculous mycobacteriosis and bronchiectasis: comparative study using national mortality statistics from 1970 to 2015 in Japan

Background

This study assessed longitudinal national data on mortality due to nontuberculous mycobacteriosis (NTMosis) and bronchiectasis and the association between the two diseases.

Methods

We analysed the national death statistics of Japan from 1970 to 2015. The International Classification of Disease (ICD) codes were used to extract the relevant data. Crude mortality, age-adjusted mortality and standardised mortality rates were calculated using vital statistics and the population in 2000. We also identified domestic publications related to NTMosis and bronchiectasis with an internet-based search system.

Results

The total number of bronchiectasis-related deaths remained at the same level, which was approximately 1000, for 45 years, although the number of deaths has consistently decreased in males but increased in females since the mid-1990s. A substantial increasing trend in females was also observed for NTMosis in the same period. The age-adjusted mortality data showed an increase in mortality in women due to NTMosis and confirmed the trend in bronchiectasis in women. The patterns in the number of domestic reports showed a recent slight increase in bronchiectasis and a marked increase in NTMosis.

Conclusions

The trends in bronchiectasis-related mortality differed by sex. The epidemiological trends in the two diseases were associated, especially in elderly females since the mid-1990s. It is suggested that pulmonary NTMosis without pre-existing bronchiectasis might be a leading cause of postinfectious bronchiectasis in Japan.

Gastroesophageal Reflux Disease Increases Susceptibility to Nontuberculous Mycobacterial Pulmonary Disease

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common comorbidity of nontuberculous mycobacteria (NTM) pulmonary disease (PD). Although GERD is associated with more symptoms and severe disease in patients with NTM PD, whether GERD is associated with an increased risk of NTM PD developing is unknown.

RESEARCH QUESTION

Does GERD influence the development of NTM PD? Are there any factors associated with an increased risk of NTM PD among patients with GERD? What is the impact of NTM PD on the health-care use of patients with GERD?

STUDY DESIGN AND METHODS

Data from the Korean National Health Insurance Service National Sample Cohort between 2002 and 2015 were used. The incidence and risk of NTM PD were compared between patients with GERD (GERD cohort; n = 17,424) and patients matched for age, sex, type of insurance, and Charlson Comorbidity Index (matched cohort; n = 69,696). Using the GERD cohort, the factors associated with incident NTM PD also were evaluated.

RESULTS

During a median follow-up duration of 5.1 years, the age- and sex-adjusted incidence of NTM PD was significantly higher in the GERD cohort (34.8 per 100,000 person-years [PY]) than in the matched cohort (10.5 per 100,000 PY; P < .001), with a subdistribution hazard ratio (HR) of 3.36 (95% CI, 2.10-5.37). Regarding risk factors associated with NTM PD, age of 60 years or older (adjusted HR, 3.57; 95% CI, 1.58-8.07) and bronchiectasis (adjusted HR, 18.69; 95% CI, 6.68-52.28) were associated with an increased risk of incident NTM PD in the GERD cohort. Compared with patients with GERD who did not demonstrate NTM PD, those with NTM PD showed higher all-cause (13,321 PY vs 5,932 PY; P = .049) and respiratory disease-related (5,403 vs 801; P = .011) ED visits or hospitalizations.

INTERPRETATION

GERD is associated with an increased incidence of NTM PD. Older age and bronchiectasis are risk factors for NTM PD in patients with GERD. NTM PD in patients with GERD is associated with increased health-care use.

Association between non-cystic fibrosis bronchiectasis and the risk of incident dementia: A nationwide cohort study

BACKGROUND

Chronic lung diseases, such as chronic obstructive pulmonary disease or asthma, are associated with an increased risk of dementia. However, few data are available regarding the risk of dementia in individuals with bronchiectasis.

OBJECTIVES

To explore the association between bronchiectasis and the risk of incident dementia using a longitudinal population-based cohort.

METHODS

A total of 4,068,560 adults older than 50 years without previous dementia were enrolled from the Korean National Health Insurance Service database in 2009. They were followed up until the date of the diagnosis of dementia or December 31, 2020. The study exposure was the diagnosis of bronchiectasis, and the primary outcome was incident dementia comprising Alzheimer's disease and vascular dementia.

RESULTS

During the median follow-up duration of 9.3 years, the incidence of all-cause dementia was 1.6-fold higher in individuals with bronchiectasis than in those without bronchiectasis (15.0 vs. 9.3/1000 person-years, p < .001). In the multivariable Cox regression analysis, the risk of all dementia was significantly higher in individuals with bronchiectasis than in those without bronchiectasis (adjusted hazard ratio [aHR] 1.09, 95% confidence interval [CI] 1.04-1.14). In a subgroup analysis by dementia type, individuals with bronchiectasis had an increased risk of Alzheimer's disease compared to those without bronchiectasis (aHR 1.07, 95% CI 1.01-1.12); the risk of vascular dementia did not significantly differ between the two groups (aHR 1.05, 95% CI 0.90-1.21).

CONCLUSION

Bronchiectasis was associated with an increased risk of dementia, especially Alzheimer's disease.

Cardiovascular and cerebrovascular-associated mortality in patients with preceding bronchiectasis exacerbation

BACKGROUND

Bronchiectasis is associated with an increased incidence of atherosclerotic cardiovascular disease (ASCaVD) and atherosclerotic cerebrovascular disease (ASCeVD). Its effect on associated mortality is unclear.

OBJECTIVES

This study investigated the effects of bronchiectasis exacerbation prior to ASCaVD or ASCeVD events on mortality in patients with bronchiectasis using a large population-based database.

METHODS

A retrospective cohort of patients with bronchiectasis who experienced ASCaVD (n = 1066) or ASCeVD (n = 825) was studied for the first time using a nationwide population-based database (National Health Insurance Service-National Sample Cohort, Korea, 2002-2015). We classified each cohort according to the presence of moderate bronchiectasis exacerbation within 1 year before the ASCaVD or ASCeVD event. We evaluated 90-day, 1-year, and all-cause mortalities risk.

RESULTS

Within 1 year before the index ASCaVD or ASCeVD event, 149 (13.9%) and 112 (13.6%) patients with bronchiectasis experienced moderate exacerbation(s), respectively. Mild exacerbations did not different in frequency between the survivors and nonsurvivors. In both cohorts, more nonsurvivors experienced moderate exacerbations than survivors. The odds ratios of 90-day and 1-year mortalities and hazard ratios of all-cause mortalities on experiencing moderate exacerbations were 2.27 [95% confidence interval (CI) = 1.26-4.10], 3.30 (95% CI = 2.03-5.38), and 1.78 (95% CI = 1.35-2.34) in the bronchiectasis-ASCaVD cohort and 1.73 (95% CI = 0.94-3.19), 1.79 (95% CI = 1.07-3.00), and 1.47 (95% CI = 1.10-1.95), in the bronchiectasis-ASCeVD cohort.

CONCLUSION

Hospitalization or emergency room visit for bronchiectasis exacerbation within 1 year before ASCaVD or ASCeVD is associated with an increased ASCaVD- or ASCeVD-associated mortality.

The incidence of bronchiectasis in chronic obstructive pulmonary disease

Bronchiectasis is a common comorbidity in chronic obstructive pulmonary disease (COPD). There are limited data regarding the incidence of bronchiectasis in COPD. The purpose of the study was to use a nationwide database to evaluate the incidence of bronchiectasis in COPD in Taiwan. We used a cohort of 2,000,000 individuals followed from 2005 to 2018. Patients with COPD diagnosed between January 1, 2011, and December 31, 2017, were selected, and those with bronchiectasis before COPD were excluded. In total, 134,366 patients with COPD were enrolled, and propensity score matching was used to ensure homogeneity of baseline characteristics between the COPD and non-COPD groups. The incidence rate of bronchiectasis was higher in the COPD group than in the non-COPD group (87.83 vs 69.80 per 10,000 person-years). The adjusted hazard ratio (1.9; 95% confidence interval 1.75-2.05; P < 0.001) of bronchiectasis indicated that the risk of bronchiectasis was 1.9 times higher for patients with COPD than for patients without COPD. In the COPD group, the age-stratified incidence rates of bronchiectasis increased with age (55.01, 80.92, 101.52, and 105.23 for 40-49, 50-59, 60-69, and over 70 years, respectively). The incidence of bronchiectasis was higher in patients with COPD than in the general population, the risk of bronchiectasis increased with age in COPD, and post-tuberculosis status was an important risk factor for bronchiectasis.

Impacts of Asthma in Patients With Bronchiectasis: Findings From the KMBARC Registry

PURPOSE

Although the coexistence of asthma and bronchiectasis is common, the impacts of asthma on bronchiectastic patients (BE) have not been well evaluated because this issue using bronchiectasis cohorts has been investigated in only a few studies.

METHODS

In the present study, 598 patients who were prospectively enrolled in the Korean bronchiectasis registry were evaluated. The clinical characteristics between BE with asthma and those without asthma were compared.

RESULTS

Asthma was found in 22.4% of BE. BE with asthma had a higher body mass index (BMI) (P = 0.020), more dyspnea (P < 0.001), larger sputum volume (P = 0.015), and lower forced expiratory volume in 1 second (FEV1) (P < 0.001) than those without asthma. BE with asthma had a higher rate of previous pneumonia (P = 0.017) or measles (P = 0.037) than those without asthma. Regarding treatment, BE with asthma used inhaled corticosteroids, long-acting muscarinic antagonists, and leukotriene receptor antagonists more frequently than those without asthma. Although intergroup differences were not observed in disease severity of bronchiectasis (P = 0.230 for Bronchiectasis Severity Index and P = 0.089 for FACED), the Bronchiectasis Health Questionnaire (BHQ) scores indicating the quality of life, were significantly lower in BE with asthma than in those without asthma (61.6 vs. 64.8, P < 0.001). In a multivariable model adjusting for age, sex, body mass index, forced expiratory volume in 1 second %predicted, sputum volume, modified Medical Research Council dyspnea scale ≥ 2, and the number of involved lobes, asthma was associated with lower BHQ scores (β-coefficient = -2.579, P = 0.014).

CONCLUSIONS

BE with asthma have more respiratory symptoms, worse lung function, and poorer quality of life than those without asthma. A better understanding of the impacts of asthma in BE will guide appropriate management in this population.

Association between exercise and risk of cardiovascular diseases in patients with non-cystic fibrosis bronchiectasis

BACKGROUND

Although cardiovascular comorbidities negatively impact survival in patients with bronchiectasis, there is limited evidence to recommend exercise in this population. We aimed to evaluate whether exercise habit changes are related to reduced cardiovascular disease risk and explore an optimal exercise amount.

METHODS

This study identified 165,842 patients with newly diagnosed bronchiectasis during 2010-2016 who underwent two health examinations and were followed up until December 2020. The exposure was the change in weekly habits of moderate- or vigorous-intensity physical activity between the two examinations, classified into non-exercisers and exercisers (further classified into new exercisers, exercise dropouts, and exercise maintainers). The amount of exercise was measured using metabolic equivalents of task (MET). The outcome was the incidence of myocardial infarction (MI) or stroke.

RESULTS

During a mean of 6.2 ± 2.1 follow-up years, 4,233 (2.6%) and 3,745 (2.3%) of patients with bronchiectasis had MI or stroke, respectively. Compared to non-exercisers, exercisers had a significantly lower risk of MI or stroke by 9-28% (p < 0.001 for both). Among exercisers, exercise maintainers showed the lowest risk of MI (adjusted hazard ratio [aHR], 0.72; 95% confidence interval [CI], 0.64-0.81) and stroke (aHR, 0.72; 95% CI, 0.64-0.82) compared to non-exercisers. Regarding exercise amount, a significant risk reduction was observed only in patients with bronchiectasis who exercised for ≥ 500 MET-min/wk.

CONCLUSION

Exercise was associated with a reduced risk of cardiovascular diseases in patients with bronchiectasis. In particular, the risk was lowest in exercise maintainers, and cardiovascular risk reduction was significant when exercising more than 500 MET-min/wk.

Prevalence of chronic rhinosinusitis and its relating factors in patients with bronchiectasis: findings from KMBARC registry

BACKGROUND/AIMS

Patients with bronchiectasis often present with respiratory symptoms caused by chronic rhinosinusitis (CRS). However, studies on the prevalence of CRS and its relationship with bronchiectasis are limited.

METHODS

The baseline characteristics of patients with bronchiectasis recruited from the Korean Multicenter Bronchiectasis Audit and Research Collaboration were analyzed. CRS diagnosis was determined by a physician, on the basis of medical records, upper airway symptoms, and/or radiologic abnormalities. Questionnaires for quality of life, fatigue, and depression were administered when patients were stable for a minimum of 4 weeks after the bronchiectasis exacerbation.

RESULTS

The prevalence of CRS was 7.1% (66/931). Patients with CRS were significantly younger than those without CRS (60.5 ± 10.7 years vs. 64.6 ± 9.3 years, p = 0.001). Idiopathic bronchiectasis was more common in patients with CRS compared to those without CRS (53.0% vs. 36.0%, p = 0.006). Lung function, inflammatory markers, exacerbations, bronchiectasis severity, and scores for quality of life, fatigue, and depression did not differ between the two groups. In a logistic regression analysis, CRS was associated with age of bronchiectasis diagnosis (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.94 to 0.99; p = 0.003) and idiopathic bronchiectasis (OR, 1.95; 95% CI, 1.12 to 3.34; p = 0.018).

CONCLUSION

The prevalence of CRS was relatively low. CRS was not associated with the severity or clinical outcomes of bronchiectasis. Early diagnosis and idiopathic etiology were associated with CRS. Our findings reflect the low recognition of CRS in the clinical practice of bronchiectasis and highlight the need for awareness of CRS by adopting objective diagnostic criteria.

Airway acidification impaired host defense against Pseudomonas aeruginosa infection by promoting type 1 interferon β response

Airway microenvironment played an important role in the progression of chronic respiratory disease. Here we showed that standardized pondus hydrogenii (pH) of exhaled breath condensate (EBC) of bronchiectasis patients was significantly lower than that of controls and was significantly correlated with bronchiectasis severity index (BSI) scores and disease prognosis. EBC pH was lower in severe patients than that in mild and moderate patients. Besides, acidic microenvironment deteriorated Pseudomonas aeruginosa (P. aeruginosa) pulmonary infection in mice models. Mechanistically, acidic microenvironment increased P. aeruginosa outer membrane vesicles (PA_OMVs) released and boosted it induced the activation of interferon regulatory factor3 (IRF3)-interferonβ (IFN-β) signalling pathway, ultimately compromised the anti-bacteria immunity. Targeted knockout of IRF3 or type 1 interferon receptor (IFNAR1) alleviated lung damage and lethality of mice after P. aeruginosa infection that aggravated by acidic microenvironment. Together, these findings identified airway acidification impaired host resistance to P. aeruginosa infection by enhancing it induced the activation of IRF3-IFN-β signalling pathway. Standardized EBC pH may be a useful biomarker of disease severity and a potential therapeutic target for the refractory P. aeruginosa infection. The study also provided one more reference parameter for drug selection and new drug discovery for bronchiectasis.

Risk Factors of Incident Lung Cancer in Patients with Non-Cystic Fibrosis Bronchiectasis: A Korean Population-Based Study

BACKGROUND

Patients with non-cystic fibrosis bronchiectasis have an increased risk of lung cancer, followed by higher mortality in this population. Because the risk factors of lung cancer have not been well identified, this study aimed to investigate the risk factors of lung cancer in individuals with newly diagnosed bronchiectasis.

METHODS

This cohort study using the Korean National Health Insurance Service database identified 7425 individuals with incident bronchiectasis among those who participated in the health screening exam in 2009. The cohort was followed from baseline to the date of incident: lung cancer, death, or until the end of the study period. We investigated the risk factors of lung cancer in participants with bronchiectasis using the Cox-proportional hazard models.

RESULTS

During median 8.3 years of follow-up duration, 1.9% (138/7425) developed lung cancer. In multivariable analyses, significant factors associated with increased risk of incident lung cancer included: males (adjusted hazard ratio [HR] = 3.54, 95% confidence interval [CI] = 2.17-5.79) than females, the overweight (adjusted HR = 1.55, 95% CI = 1.03-2.35) than the normal weight, current smokers (adjusted HR = 3.10, 95% CI = 2.00-4.79) than never smokers, participants living in the rural area (adjusted HR = 2.54, 95% CI = 1.68-3.85) than those living in the metropolitan area. Among comorbidities, chronic obstructive pulmonary disease was associated with an increased risk of lung cancer (adjusted HR = 1.46, 95% CI = 1.01-2.13) in participants with bronchiectasis. In contrast, mild alcohol consumption was associated with reduced risk of lung cancer (adjusted HR = 0.47, 95% CI = 0.29-0.74) in those with bronchiectasis.

CONCLUSION

This Korean population-based study showed that males, current smoking, overweight, living in rural areas, and comorbid chronic obstructive pulmonary disease are associated with increased risk of lung cancer in individuals with bronchiectasis.

Non-Cystic Fibrosis Bronchiectasis Increases the Risk of Lung Cancer Independent of Smoking Status

Rationale

It remains unclear whether non-cystic fibrosis bronchiectasis increases the risk of lung cancer, because smoking history was not considered in previous studies.

Objectives

To evaluate whether participants with bronchiectasis have a higher risk of incident lung cancer than those without bronchiectasis with information on smoking status.

Methods

This was a population-based cohort study of 3,858,422 individuals who participated in the 2009 National Health Screening Program. We evaluated the incidence of lung cancer in participants with bronchiectasis (n = 65,305) and those without bronchiectasis (n = 3,793,117). We followed the cohort up until the date of lung cancer diagnosis, date of death, or December 2018. Cox proportional hazard regression models were used to evaluate the relative risk of lung cancer between participants with bronchiectasis and those without bronchiectasis.

Results

The incidence of lung cancer in participants with bronchiectasis was significantly higher than in those without bronchiectasis (2.1 vs. 0.7 per 1,000 person-years; P < 0.001), with an adjusted hazard ratio (aHR) of 1.22 (95% confidence interval [CI], 1.14–1.30) in the model adjusting for potential confounders and accounting for the competing risk of mortality. Regardless of smoking status, the risk of lung cancer was significantly higher in participants with bronchiectasis than in those without bronchiectasis (aHR, 1.28 [95% CI, 1.17–1.41] for never-smokers; aHR, 1.26 [95% CI, 1.10–1.44] for ever-smokers). Although bronchiectasis did not increase the risk of lung cancer among participants with chronic obstructive pulmonary disease (COPD), it significantly increased the risk of lung cancer in participants without COPD (aHR, 1.19 [95% CI, 1.09–1.31]).

Conclusions

The presence of bronchiectasis was associated with a higher risk of lung cancer after considering the smoking status.

Increasing prevalence and burden of bronchiectasis in urban Chinese adults, 2013-2017: a nationwide population-based cohort study

Background

While the prevalence and disease burden of bronchiectasis are increasing, data in the world’s largest population are lacking. We aimed to investigate the prevalence and disease burden of bronchiectasis in Chinese adults.

Methods

We conducted a population-based study using data between 2013 and 2017 from the national databases of Urban Employee Basic Medical Insurance and Urban Resident Basic Medical Insurance in China. Data from over 380 million patients aged 18 years and older during the study period were analyzed, and a total of 383,926 bronchiectasis patients were identified. Primary outcomes included the age- and sex-specific prevalence of bronchiectasis. Annual visits and hospitalizations, as well as annual costs were also calculated.

Results

The prevalence of bronchiectasis in Chinese adults increased 2.31-fold, from 75.48 (62.26, 88.69) per 100,000 in 2013 to 174.45 (137.02, 211.88) per 100,000 in 2017. The increase was more remarkable for patients aged over 50 years in both genders. The per-capita total cost and hospitalization cost of patients with bronchiectasis increased 2.18-fold and 1.83-fold from 2013 to 2017, respectively, mostly driven by non-bronchiectasis costs. The average annual hospitalization ranged from 1.20 to 1.24 times during the 5 years.

Conclusion

The prevalence and disease burden of bronchiectasis in Chinese urban adults ≥ 18 years had increased significantly between 2013 and 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02023-8.

Association between Smoking Status and Incident Non-Cystic Fibrosis Bronchiectasis in Young Adults: A Nationwide Population-Based Study

Smoking traditionally has not been considered as a cause of bronchiectasis. However, few studies have evaluated the association between smoking and bronchiectasis. This study aimed to investigate the association between smoking status and bronchiectasis development in young adults. This study included 6,861,282 adults aged 20−39 years from the Korean National Health Insurance Service database 2009−2012 who were followed-up until the date of development of bronchiectasis, death, or 31 December 2018. We evaluated the incidence of bronchiectasis according to smoking status. During a mean of 7.4 years of follow-up, 23,609 (0.3%) participants developed bronchiectasis. In multivariable Cox regression analysis, ex-smokers (adjusted hazard ratio (aHR) = 1.07, 95% confidence interval (CI) = 1.03−1.13) and current-smokers (aHR = 1.06, 95% CI = 1.02−1.10) were associated with incident bronchiectasis, with the highest HR in ≥ 10 pack-years current smokers (aHR = 1.12, 95% CI = 1.06−1.16). The association of smoking with bronchiectasis was more profound in females than in males (p for interaction < 0.001), in younger than in older participants (p for interaction = 0.036), and in the overweight and obese than in the normal weight or underweight (p for interaction = 0.023). In conclusion, our study shows that smoking is associated with incident bronchiectasis in young adults. The association of smoking with bronchiectasis development was stronger in females, 20−29 year-olds, and the overweight and obese than in males, 30−40-year-olds, and the normal weight or underweight, respectively.

Healthcare Utilization and Medical Cost of Gastrointestinal Reflux Disease in Non-tuberculous Mycobacterial Pulmonary Disease: A Population-Based Study, South Korea, 2009–2017

Gastroesophageal reflux disease (GERD) is a common non-respiratory comorbidity in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD). However, little is known about the association between GERD and healthcare utilization and medical costs of NTM-PD. Thus, we evaluated this association using the Health Insurance Review and Assessment Service National Patient Sample. NTM-PD patients with GERD had significantly higher healthcare use and spent a higher total on medical costs (5,098 vs. 2,675 USD/person/year) than those without GERD (P <0.001 for all). Therefore, an appropriate management of GERD in NTM-PD patients can be an important factor to reduce the disease burden.

Research advances and clinical management of bronchiectasis: Chinese perspective

Bronchiectasis is a debilitating chronic suppurative airway disease that confers a substantial burden globally. Despite the notable prevalence, research on bronchiectasis in mainland China remains in its infancy. Nevertheless, there has been a significant leap in the quantity and quality of research, which has contributed to the ever-improving clinical practice. A nationwide collaborative platform has been established to foster multicentre studies, which will help increase the level of evidence further. Here, we summarise the status quo of clinical management and consider the research priorities for bronchiectasis that have been published previously. We also highlight the efforts of the Chinese medical communities to outline the core tasks that need to be addressed within the next decade.

Increased hospitalizations and economic burden in COPD with bronchiectasis: a nationwide representative study

With the increasing use of computed tomography, bronchiectasis has become a common finding in patients with chronic obstructive pulmonary disease (COPD). However, the clinical aspects and medical utilization of COPD with bronchiectasis (BE) remain unclear. We aimed to investigate the BE effect on prognosis and medical utilization in patients with COPD. Among 263,747 COPD patients, we excluded patients lacking chest X-ray, CT, or pulmonary function test codes and classified 2583 GOLD-C/D patients matched according to age, sex, and medical aid as having COPD-BE (447 [17.3%]) and COPD without BE (2136 [82.7%]). Patients with COPD-BE showed a higher rate of acute exacerbation requiring antibiotics than those without BE. Moreover, multivariable analysis showed that BE co-existence was a crucial factor for moderate-to-severe exacerbation (incidence rate ratio [IRR] 1.071; 95% CI 1.012-1.134; p = 0.019). Patients with COPD-BE had a significantly higher rate of exacerbations requiring antibiotics, as well as treatment cost and duration (meant as number of days using hospitalization plus outpatient appointment), than those with COPD without BE (52.64 ± 65.29 vs. 40.19 ± 50.02 days, p < 0.001; 5984.08 ± 8316.96 vs. 4453.40 ± 7291.03 USD, p < 0.001). Compared with patients with COPD without BE, patients with COPD-BE experienced more exacerbations requiring antibiotics, more hospitalizations, and a higher medical cost.

Female reproductive factors and incidence of non-tuberculous mycobacterial pulmonary disease among postmenopausal women in Korea

BACKGROUND

There are conflicting results regarding endogenous estrogen exposure and risk of incident non-tuberculous mycobacterial pulmonary disease (NTM-PD). In addition, the impact of hormone replacement therapy (HRT) on risk of NTM-PD is lacking. This study aimed to evaluate the impacts of endogenous estrogen exposure and HRT on risk of NTM-PD in postmenopausal women.

METHODS

This population-based cohort study consisted of 1,400,095 postmenopausal women without previous NTM-PD who participated in the 2009 national health screening exam in South Korea. The cohort was followed until the date of incident NTM-PD, death, or December 2018. We evaluated whether lifetime endogenous estrogen exposure and HRT were associated with incident NTM-PD. Endogenous estrogen exposure was evaluated using age at menarche, age at menopause, and reproductive period (duration between age at menarche and age at menopause).

RESULTS

During a median of 8.4 (interquartile range, 8.2-8.7) years of follow-up, 0.1% of participants (1,818/1,400,095) developed NTM-PD, with an incidence rate of 0.15/1000 person-years. Multivariable Cox regression analyses showed no significant relationship between endogenous estrogen exposure (age at menarche, age at menopause, and reproductive period) and risk of NTM-PD. In contrast, duration of HRT showed a significant dose-response relationship with incident NTM-PD even after adjustment of demographics and reproductive factors (adjusted hazard ratio [95% confidence interval]; 1.30 [1.12-1.51] in HRT for < 2 years, 1.28 [1.03-1.59] in 2-5 years, and 1.65 [1.33-2.05] in ≥ 5 years).

CONCLUSIONS

While there was no significant association with endogenous estrogen exposure, HRT was monotonically associated with increased risk of NTM-PD in postmenopausal women.

Female Reproductive Factors and the Risk of Bronchiectasis: A Nationwide Population-Based Longitudinal Study

Although the oestrogen level is thought to be involved in the occurrence of bronchiectasis, limited data are available on the relationship between female reproductive factors and the risk of bronchiectasis. We performed a population-based retrospective cohort study of 959,523 premenopausal women and 1,362,401 postmenopausal women without a previous history of bronchiectasis who participated in a health screening exam in 2009 in South Korea. In premenopausal women, compared with a later age at menarche (≥16 years), an earlier menarche (<12 years) was associated with a reduced risk of bronchiectasis with an adjusted hazard ratio (aHR) (95% confidence interval (CI)) of 0.74 (0.67–0.81). However, there were no significant associations between other reproductive factors (breastfeeding, parity, or oral contraceptive use) and the risk of bronchiectasis. In postmenopausal women, the risk of bronchiectasis (aHR (95% CI)) was lower in those with an earlier menarche (0.79 (0.72–0.87) for <12 years vs. ≥16 years), a later menopause (0.90 (0.84–0.96) ≥55 years vs. <40 years), and a longer reproductive period (0.90 (0.86–0.94) for ≥40 years vs. <30 years). There was no significant relationship between parity and the risk of bronchiectasis. Although breastfeeding <1 year (aHR (95% CI) = 0.92 (0.87–0.97) for <0.5 years and 0.93 (0.88–0.97) for 0.5–1 years) and oral contraceptive use <1 year (0.97 (0.94–0.99)) reduced the risk of bronchiectasis, hormone replacement therapy ≥5 years increased the risk of bronchiectasis (1.24 (1.18–1.30)). Female reproductive factors are risk factors for developing bronchiectasis, showing a higher risk associated with shorter endogenous oestrogen exposure regardless of the menopausal status.

Gastro-oesophageal reflux disease increases healthcare use and medical costs in patients with bronchiectasis: a Korean nationwide population-based study

BACKGROUND

Gastro-oesophageal reflux disease (GORD) is not only a common aetiology but also accompanying comorbidity of non-cystic fibrosis bronchiectasis (bronchiectasis). However, the association between GORD and the disease burden of bronchiectasis has not been well evaluated. Our study aimed to evaluate whether GORD is associated with increased healthcare use and medical costs in patients with bronchiectasis.

METHODS

We analyzed the data from 44,119 patients with bronchiectasis using a large representative Korean population-based claim database between 2009 and 2017. We compared the healthcare use [outpatient department (OPD) visits and emergency room (ER) visits/hospitalizations] and medical costs in patients with bronchiectasis according to the presence or absence of GORD.

RESULTS

The prevalence of GORD in patients with bronchiectasis tended to increase during the study period, especially in the 50s and older population. GORD was associated with increased use of all investigated healthcare resources in patients with bronchiectasis. Healthcare use including OPD visits (mean 47.6/person/year versus 30.0/person/year), ER visits/hospitalizations (mean 1.7/person/year versus 1.1/person/year), and medical costs (mean 3564.5 Euro/person/year versus 2198.7 Euro/person/year) were significantly higher in bronchiectasis patients with GORD than in those without GORD (p < 0.001 for all). In multivariable analysis, bronchiectasis patients with GORD showed 1.44-fold (95% confidence interval = 1.37-1.50) and 1.26-fold (95% confidence interval = 1.19-1.33) increased all-cause and respiratory-related ER visits/hospitalizations relative to those without GORD, respectively. After adjusting for potential confounders, the estimated total medical costs (mean 4337.3 versus 3397.4 Euro/person/year) and respiratory disease-related medical costs (mean 920.7 versus 720.2 Euro/person/year) were significantly higher in bronchiectasis patients with GORD than in those without GORD (p < 0.001 for both).

CONCLUSION

In patients with bronchiectasis, GORD was associated with increased healthcare use and medical costs. Strategies to reduce the disease burden associated with GORD are needed in patients with bronchiectasis.

Body Mass Index, Diabetes, and Risk of Tuberculosis: A Retrospective Cohort Study

Although both diabetes mellitus (DM) and underweight are associated with increased risk of tuberculosis (TB), there are limited data evaluating TB risk while considering two factors simultaneously—body mass index (BMI) and DM. A retrospective cohort study was performed with 10,087,903 participants of the Korean National Health Screening Program in 2009. The cohort was followed up to the date of TB incidence, death, or until December 31, 2018. We compared the incidence and risk of TB according to BMI category and DM. During the 7.3-year follow-up duration, the incidence of TB was 0.92 per 1,000 person-years in the normal weight without DM, 2.26 in the normal weight with DM, 1.80 in the underweight without DM, and 5.35 in the underweight with DM. Compared to the normal weight without DM, the normal weight with DM, the underweight without DM, and the underweight with DM showed a 1.51-fold (95% CI, 1.46–1.57), a 2.21-fold (95% CI, 2.14–2.28), and a 3.24-fold (95% CI, 2.95–3.56) increased risk of TB, respectively. However, compared to the normal weight without DM, the severely obese without DM and those with DM showed a 0.37 (95% CI, 0.36–0.38) and a 0.42 (95% CI, 0.36–0.48)-fold decreased risk of TB, respectively. There was no significant joint effect of BMI and DM on the risk of incident TB in the overall population; a synergistic effect of underweight and DM was evident in participants <65 years of age, current smokers, and heavy drinkers. In conclusion, being underweight or DM individually increases the risk of incident TB. Based on our study results, a focused screening of incident TB in patients with DM may be beneficial.

Developing a diagnostic bundle for bronchiectasis in South Korea: A modified Delphi Consensus Study

Background

A diagnostic bundle for bronchiectasis in South Korea is necessary because the etiologies of bronchiectasis and related diseases vary significantly among different regions and ethnicities.

Methods

A modified Delphi method was used to develop expert consensus statements on a diagnostic bundle for bronchiectasis in South Korea. Initial statements proposed by a core panel, based on international bronchiectasis guidelines, were discussed over one online meeting and two email surveys by a panel of experts (≥70% agreement).

Results

Twenty-one experts participated in the study, and 30 statements on a diagnostic bundle for bronchiectasis were classified as recommended, conditional, or not recommended. The expert panel agreed that 1) a standardized diagnostic bundle is useful in clinical practice, 2) diagnostic tests for specific diseases, including immunodeficiency and allergic bronchopulmonary aspergillosis, are necessary when clinically suspected, 3) initial diagnostic tests, including sputum microbiology and spirometry, are essential in all bronchiectasis patients, and 4) patients should be referred to specialized centers when rare causes such as primary ciliary dyskinesia are suspected.

Conclusion

In this Delphi survey, expert consensus statements were generated on which specific diagnostic, laboratory, microbiologic, and pulmonary function tests to obtain when managing patients with bronchiectasis in South Korea.

Long-Term Prognosis of Asthma-Bronchiectasis Overlapped Patients: A Nationwide Population-Based Cohort Study

Purpose

Asthma and bronchiectasis are common chronic respiratory diseases, and their coexistence is frequently observed but not well investigated. Our aim was to study the effect of comorbid bronchiectasis on asthma.

Methods

A propensity score-matched cohort study was conducted using the National Health Insurance Service-Health Screening Cohort database. From 2005 to 2008, 8,034 participants with asthma were weighted based on propensity scores in a 1:3 ratio with 24,099 participants without asthma. From the asthma group, 141 participants with overlapped bronchiectasis were identified, and 7,892 participants had only asthma. Clinical outcomes of acute asthma exacerbation(s) and mortality rates were compared among the study groups.

Results

The prevalence of bronchiectasis (1.7%) was 3 times higher in asthmatics than in the general population of Korea. Patients who had asthma comorbid with bronchiectasis experienced acute exacerbation(s) more frequently than non-comorbid patients (11.3% vs. 5.8%, P = 0.007). Time to the first acute exacerbation was also shorter in the asthmatics with bronchiectasis group (1,970.9 days vs. 2,479.7 days, P = 0.005). Although bronchiectasis was identified as a risk factor for acute exacerbation (adjusted odds ratio, 1.73; 95% confidence interval [CI], 1.05–2.86), there was no significant relationship between bronchiectasis and all-cause or respiratory mortality (adjusted hazard ratio [aHR], 1.17; 95% CI, 0.67–2.04 and aHR, 0.81; 95% CI, 0.11–6.08).

Conclusions

Comorbid bronchiectasis increases asthma-related acute exacerbation, but it does not-raise the risk of all-cause or respiratory mortality. Close monitoring and accurate diagnosis of bronchiectasis are required for patients with frequent exacerbations of asthma.

Survey of the management of patients with bronchiectasis: a pilot investigation in Asian populations

BACKGROUND/AIMS

Although international guidelines for bronchiectasis management have been published in Western countries, there is a lack of data about their application in Asian populations including patients with different phenotypes. We aimed to investigate the current status of bronchiectasis management in Asian populations.

METHODS

A nationwide questionnaire survey was performed of Asian respiratory specialists from South Korea, Japan, Taiwan, Singapore, Vietnam, and Sri Lanka. Participants were invited by e-mail to answer a questionnaire comprising 25 questions based on international guidelines for the management of bronchiectasis.

RESULTS

A total of 221 physicians participated in the survey. About half of them were Korean (50.2%), with the next most common nationalities being Japanese (23.1%), Taiwanese (13.6%), and Singaporean (7.7%). Only 18 (8.1%) responders had local guidelines for bronchiectasis. While 85 (38.5%) responders checked sputum acid-fast bacillus smear/culture about 1 to 3 times per year, only a small proportion of responders routinely performed a serum immunoglobulin test (36/221, 16.3%) or evaluated for allergic bronchopulmonary aspergillosis (41/221, 18.6%). Less than half (43.4%) of responders performed eradication treatment in patients with drug-sensitive Pseudomonas aeruginosa infection, mainly due to the limited availability of inhaled antibiotics (34.8%). In addition, 58.6% of responders considered physiotherapy such as airway clearance and pulmonary rehabilitation.

CONCLUSION

Discrepancies might exist between guideline recommendations and practice for bronchiectasis management in Asian populations, partly due to the limited availability of treatment in each country. The development of local guidelines that consider the phenotypes and situation will help to standardize and improve the management of bronchiectasis.

Clinical Characteristics of Patients with Post-Tuberculosis Bronchiectasis: Findings from the KMBARC Registry

The clinical characteristics of patients with post-tuberculosis (TB) bronchiectasis have not been well evaluated. We enrolled 598 patients with bronchiectasis who participated in the Korean prospective bronchiectasis registry and compared the characteristics of post-TB bronchiectasis (19.7%) with post-infectious (19.6%), idiopathic (40.8%), and other (19.9%) bronchiectasis. The patients with post-TB bronchiectasis had a lower body mass index, higher rate of chronic obstructive pulmonary disease, and lower rate of asthma than those in the other groups. The patients with post-TB bronchiectasis had more upper lobe involvement, more severe radiological extent, and worse lung function than those in the other groups. Long-acting muscarinic antagonist/long-acting ß agonist use and mucolytics were more commonly used in the patients with post-TB bronchiectasis than those in the other groups, while inhaled corticosteroid/long-acting ß agonist was less commonly used. There were no significant intergroup differences in bronchiectasis severity scores except for FACED, the number of exacerbations, and quality of life. Post-TB bronchiectasis is characterised by reduced lung function and higher rates of mucolytic use when compared with other bronchiectasis; thus, adequate bronchodilator use and airway clearance techniques may alleviate symptom burden in this population.

Prevalence of depression and its associated factors in bronchiectasis: findings from KMBARC registry

BACKGROUND

With the emergence of bronchiectasis as a common respiratory disease, epidemiological data have accumulated. However, the prevalence and impact of psychological comorbidities were not sufficiently evaluated. The present study examined the prevalence of depression and its associated factors in patients with bronchiectasis.

METHODS

This study involved a multicenter cohort of bronchiectasis patients recruited from 33 pulmonary specialist hospitals. The baseline characteristics and bronchiectasis-related factors at enrollment were analyzed. Depressive symptoms were assessed using the Patient Health Questionnaire (PHQ-9).

RESULTS

Of the 810 patients enrolled in the study, 168 (20.7%) patients had relevant depression (PHQ-9 score ≥ 10), and only 20 (11.9%) patients had a diagnosis of depression. Significant differences were noted in the depressive symptoms with disease severity, which was assessed using the Bronchiectasis Severity Index and E-FACED (all p < 0.001). Depressive symptoms inversely correlated with quality-of-life (r = - 0.704, p < 0.001) and positively correlated with fatigue severity score (r = 0.712, p < 0.001). Multivariate analysis showed that depression was significantly associated with the modified Medical Research Council dyspnea scale ≥ 2 (OR 2.960, 95% CI 1.907-4.588, p =  < 0.001) and high number of exacerbations (≥ 3) in the previous year (OR 1.596, 95% CI 1.012-2.482, p = 0.041).

CONCLUSIONS

Depression is common, but its association with bronchiectasis was underrecognized. It negatively affected quality-of-life and presented with fatigue symptoms. Among the bronchiectasis-related factors, dyspnea and exacerbation were closely associated with depression. Therefore, active screening for depression is necessary to optimize the treatment of bronchiectasis.

TRIAL REGISTRATION

The study was registered at Clinical Research Information Service (CRiS), Republic of Korea (KCT0003088). The date of registration was June 19th, 2018.