Burden of asthma and COPD overlap (ACO) in Taiwan: a nationwide population-based study

COVID-19 and Long-term Risk of Ischemic Heart Disease in Asthma

Despite the importance of comorbid ischemic heart disease (IHD) in the prognosis of asthma, the long-term impact of coronavirus disease 2019 (COVID-19) on IHD in adults with asthma remains unclear. This study investigated the long-term effects of COVID-19 on the risk of IHD in individuals with asthma, particularly regarding COVID-19 severity. Using the Korean National Health Insurance Service claims database, we identified individuals with asthma who had recovered from COVID-19 between October 8, 2020, and December 31, 2021 (n = 8,011) and 1:1 propensity score-matched controls (n = 8,011). The incidence and risk of IHD were compared between the two groups. Overall, during a median follow-up of 95 days (interquartile range, 34-213 days; range, 1-448 days), which includes a median of 14 lag days, the COVID-19 cohort did not show a higher risk of IHD (hazard ratio [HR], 2.11; 95% confidence interval [CI], 0.99-4.48) compared to matched controls. However, when the severity of COVID-19 was considered, the severe COVID-19 cohort exhibited a higher risk of IHD (HR, 4.89; 95% CI, 1.86-12.84) than matched controls; in contrast, the non-severe COVID-19 cohort showed no significantly increased risk of IHD (HR, 1.64; 95% CI, 0.73-3.70). Severe COVID-19 is associated with an increased long-term risk of IHD in adults with asthma, emphasizing the importance of cardiovascular events monitoring to improve asthma treatment outcomes in the era of COVID-19.

Long-Term Impacts of COVID-19 on Severe Exacerbation and Mortality in Adult Asthma: A Nationwide Population-Based Cohort Study

BACKGROUND

In adults with asthma, the long-term impact of previous coronavirus disease 2019 (COVID-19) on severe exacerbations and mortality is unclear.

OBJECTIVE

We evaluated the long-term risk of severe exacerbation and mortality in adults with asthma who recovered from COVID-19.

METHODS

Using the Korean National Health Insurance claim-based database, we compared the risk of severe exacerbations (emergency room visits or hospitalization) and mortality in adults with asthma aged greater than 20 years who had recovered from COVID-19 between October 8, 2020, and December 16, 2021 (COVID-19 cohort, n = 10,739) with 1:1 propensity score-matched controls (n = 10,739).

RESULTS

During a median follow-up of 87 days (range, 15-448 days), the incidence rate of severe exacerbations in the COVID-19 cohort and the matched cohort was 187.3 and 119.3 per 10,000 person-years, respectively. The COVID-19 cohort had a higher risk of severe exacerbation compared with the matched cohort (hazard ratio = 1.57; 95% CI, 1.06-2.32). During a median follow-up of 360 days (range, 15-721 days), the incidence rate of death in the COVID-19 and matched cohorts was 128.3 and 73.5 per 10,000 person-years, respectively. The COVID-19 cohort had a higher risk of death (hazard ratio = 1.76; 95% CI, 1.33-2.30) compared with the matched cohort. When further analyzed by COVID-19 severity, severe COVID-19 was associated with a 5.12-fold (95% CI, 3.27-8.01) and 7.31-fold (95% CI, 5.41-9.88) increased risk of severe exacerbation and death, respectively, but non-severe COVID-19 was not.

CONCLUSIONS

Our study shows that severe COVID-19 is associated with an increased long-term risk of severe exacerbation and mortality among individuals with asthma.

Fatigue, Depression, and Anxiety in Patients with COPD, Asthma and Asthma-COPD Overlap

INTRODUCTION

Asthma and COPD are extremely common respiratory diseases that have a serious impact on people's lives around the world. A disease characterized by symptoms characteristic for asthma and COPD is called asthma-COPD overlap (ACO). Fatigue and certain psychological disorders such as anxiety and depression are important comorbidities in these diseases. The purpose of this study was to assess the prevalence of fatigue, anxiety, and depression in patients with asthma, COPD, and ACO and to also consider their mutual correlations.

MATERIAL AND METHODS

A total of 325 patients were enrolled in the study. There were 159 women and 166 men and their mean age was 63. Two standardized questionnaires were used: the Modified Fatigue Impact Scale (MFIS) and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

The mean total MFIS score for all patients was 33.03. Patients with asthma generally scored lower than patients with COPD and ACO. There were no statistical differences in the HADS for anxiety between the groups, although around half of the patients registered a score indicating some level of disorder. Patients with COPD and ACO were proven to suffer more from depression than patients with asthma. The HADS and MFIS scores were found to correlate significantly and positively.

CONCLUSIONS

Our study showed that patients with COPD, asthma, and ACO generally suffered from an increased level of fatigue and depression. Anxiety was high in all groups, but it was at a similar level for patients suffering from each of the three diseases under consideration. It is important to treat the physical symptoms as well as the psychological disorders since they greatly impact on the patient outcomes.

Self-Reported Physician Diagnosed Asthma with COPD is Associated with Higher Mortality than Self-Reported Asthma or COPD Alone - A Prospective 24-Year Study in the Population of Helsinki, Finland

Asthma and COPD are common chronic obstructive respiratory diseases. COPD is associated with increased mortality, but for asthma the results are varying. Their combination has been less investigated, and the results are contradictory. The aim of this prospective study was to observe the overall mortality in obstructive pulmonary diseases and how mortality was related to specific causes using postal questionnaire data. This study included data from 6,062 participants in the FinEsS Helsinki Study (1996) linked to mortality data during a 24-year follow-up. According to self-reported physician diagnosed asthma, COPD, or smoking status, the population was divided into five categories: combined asthma and COPD, COPD alone and asthma alone, ever-smokers without asthma or COPD and never-smokers without asthma or COPD (reference group). For the specific causes of death both the underlying and contributing causes of death were used. Participants with asthma and COPD had the highest hazard of mortality 2.4 (95% CI 1.7-3.5). Ever-smokers without asthma or COPD had a 9.5 (3.7-24.2) subhazard ratio (sHR) related to lower respiratory tract disease specific causes. For asthma, COPD and combined, the corresponding figures were 10.8 (3.4-34.1), 25.0 (8.1-77.4), and 56.1 (19.6-160), respectively. Ever-smokers without asthma or COPD sHR 1.7 (95% CI 1.3-2.5), and participants with combined asthma and COPD 3.5 (1.9-6.3) also featured mortality in association with coronary artery disease. Subjects with combined diseases had the highest hazard of overall mortality and combined diseases also showed the highest hazard of mortality associated with lower respiratory tract causes or coronary artery causes.Abbreviations: CigCigaretteCOPDChronic obstructive pulmonary diseaseCVDCardiovascular diseaseFEV₁Forced Expiratory Volume in one secondFVCForced Vital CapacityFinEsSFinland, Estonia, and Sweden study on chronic obstructive pulmonary diseasesHRHazard RatiosHRSubhazard RatioICD-10International Statistical Classifications of Diseases and Related Health Problems (Version 10).

Asthma Therapies on Pulmonary Tuberculosis Pneumonia in Predominant Bronchiectasis-Asthma Combination

Background: It is sometimes difficult to distinguish between asthma and bronchiectasis as their symptoms overlap, and these two diseases are associated with pulmonary tuberculosis (PTB) or pneumonia.

Objective: The purpose of this study is to determine the effects of bronchodilator drugs, steroids, antidepressants drugs, and antianxiety drugs on the risks of PTB or pneumonia in patients with bronchiectasis–asthma combination or bronchiectasis–asthma–chronic obstructive pulmonary disease combination—BCAS cohort.

Methods: After propensity score matching, we retrospectively studied patients with BCAS (N = 620) and without BCAS (N = 2,314) through an analysis. The cumulative incidence of PTB or pneumonia was analyzed through Cox proportional regression. After adjustment for sex, age, comorbidities, and medications [including long-acting beta2 agonist/muscarinic antagonists (LABAs/LAMAs), short-acting beta2 agonist/muscarinic antagonists (SABAs/SAMAs), leukotriene receptor antagonist, montelukast, steroids (inhaled corticosteroids, ICSs; oral steroids, OSs), anti-depressants (fluoxetine), and anti-anxiety drugs (benzodiazepines, BZDs)], we calculated the adjusted hazard ratios (aHR) and their 95% confidence intervals (95% CI) for these risks. Similar to OSs, ICSs are associated with an increased risk of PTB or pneumonia, lumping these two as steroids (ICSs/OSs).

Results: For the aHR (95% CI), with non-LABAs/non-OSs as the reference 1, the use of LABAs [0.70 (0.52–0.94)]/OSs [0.35 (0.29–0.44)] was associated with a lower risk of PTB or pneumonia. However, the current use of LABAs [2.39 (1.31–4.34)]/SABAs [1.61 (1.31–1.96)], steroids [ICSs 3.23 (1.96–5.29)]/OSs 1.76 (1.45–2.14)], and BZDs [alprazolam 1.73 (1.08–2.75)/fludiazepam 7.48 (1.93–28.9)] was associated with these risks. The current use of LAMAs [0.52 (0.14–1.84)]/SAMAs [1.45 (0.99–2.11)] was not associated with these risks.

Conclusion: The current use of LAMAs/SAMAs is relatively safe with respect to PTB or pneumonia risks, but LABAs/SABAs, steroids, and BZDs could be used after evaluation of the benefit for the BCAS cohort. However, we must take the possible protopathic bias into account.

Hospitalization for Heart Failure in the United States, UK, Taiwan, and Japan: An International Comparison of Administrative Health Records on 413,385 Individual Patients

BACKGROUND

Registries show international variations in the characteristics and outcome of patients with heart failure (HF), but national samples are rarely large, and case selection may be biased owing to enrolment in academic centers. National administrative datasets provide large samples with a low risk of bias. In this study, we compared the characteristics, health care resource use (HRU) and outcomes of patients with primary HF hospitalizations (HFH) using electronic health records (EHR) from 4 high-income countries (United States, UK, Taiwan, Japan) on 3 continents.

METHODS AND RESULTS

We used electronic health record to identify unplanned HFH between 2012 and 2014. We identified 231,512, 10,991, 36,900, and 133,982 patients with a primary HFH from the United States, the UK, Taiwan, and Japan, respectively. HFH per 100,000 population was highest in the United States and lowest in Taiwan. Fewer patients in Taiwan and Japan were obese or had chronic kidney disease. The length of hospital stay was shortest in the United States (median 4 days) and longer in the UK, Taiwan, and Japan (medians of 7, 9, and 17 days, respectively). HRU during hospitalization was highest in Japan and lowest in UK. Crude and direct standardized in-hospital mortality was lowest in the United States (direct standardized rates 1.8, 95% confidence interval 1.7%-1.9%) and progressively higher in Taiwan (direct standardized rates 3.9, 95% CI 3.8%-4.1%), the UK (direct standardized rates 6.4, 95% CI 6.1%-6.7%), and Japan (direct standardized rates 6.7, 95% CI 6.6%-6.8%). The 30-day all-cause (25.8%) and HF (7.2%) readmissions were highest in the United States and lowest in Japan (11.9% and 5.1%, respectively).

CONCLUSIONS

Marked international variations in patient characteristics, HRU, and clinical outcomes exist; understanding them might inform health care policy and international trial design.

Relationship between exposure to ozone and exacerbation requiring hospital admission among patients with asthma: a case-control study in central Taiwan

OBJECTIVE

The convergence of asthma and air pollutants in ageing populations is currently a growing health issue worldwide, and hence there is an essential need to investigate the association between exposure to air pollution, particularly ozone (O₃), and exacerbation requiring admission in patients with asthma.

SETTING

A case-control study at a tertiary referral hospital in central Taiwan.

PARTICIPANTS

We used an asthma cohort, which included 11 400 patients with asthma, for the period 2006-2018 at Taichung Veterans General Hospital.

PRIMARY AND SECONDARY OUTCOME MEASURES

We identified patients who had admitted for exacerbation as cases and selected patients with asthma without exacerbation, matching (1:4) the cases for age, gender and season of exacerbation, as controls. Data on hourly level of air pollutants were obtained from the Taiwan Environmental Protection Administration. We used conditional logistic regression and calculated adjusted ORs (adjORs) with 95% CIs.

RESULTS

We enrolled 11 400 participants with asthma, and 4.4% (501) of them had been admitted for exacerbation. Participants with asthma with exacerbation requiring hospitalisation were exposed to a higher level of O₃ 8-hour daily maximum (adjOR 1.009, 95% CI 1.001 to 1.016) and were more likely to have high Charlson Comorbidity Index (CCI ≥3; adjOR 2.198, 95% CI 1.729 to 2.794) and asthma-chronic obstructive pulmonary disease overlap (adjOR 4.542, 95% CI 3.376 to 6.611) compared with those without exacerbation. The aforementioned associations between exacerbation of asthma requiring hospitalisation and exposure to O₃ were similar when defined by either O₃ 1-hour daily maximum or O₃ 24-hour average. Moreover, the O₃ relevant exacerbation of asthma mainly existed in those aged older than 65 years and patients with medical comorbidities, including gastrointestinal diseases, cardiovascular diseases, neurological diseases, diabetes and renal disease.

CONCLUSIONS

Our findings highlight the need for vigilance of exposure to O₃ among elderly with asthma, particularly those with medical comorbidities. Further studies are warranted to investigate the underlying mechanisms.

The effects of medications for treating COPD and allied conditions on stroke: a population-based cohort study

Patients with chronic obstructive pulmonary disease (COPD) are at higher risk of stroke. This study aimed to investigate the clinical factors of stroke risk in COPD and allied conditions patients and associations between medications for treating COPD and allied conditions. The population-based study cohort comprised 24,173 patients diagnosed with COPD and allied conditions between 2000 and 2013, and 24,170 selected matched patients without COPD comprised the comparison cohort from a nationwide database. Cox-proportional hazard regression was performed to determine the impact of medical therapies, comorbidities, and other clinical factors on stroke risk. Of the 48,343 included patients, 1394 (2.9%) experienced stroke during follow-up, with a significant difference between COPD and allied conditions cohort (1003/4.2%) and comparison cohort (391/1.6%) (adjusted hazard ratio [aHR]: 2.72, p < 0.001). Cox-regression analysis revealed that COPD and allied conditions patients who were older (>65 years) (HR: 1.06); male (HR: 1.39); with hypertension (HR: 1.46), diabetes mellitus (HR: 1.33) and atrial fibrillation (HR: 1.63) had increased stroke risk. Mucolytics (HR: 0.44) and combination therapy with inhaled corticosteroids (ICS) and long-acting β2-agonists (LABA) (HR: 0.75) were associated with decreased stroke risk in COPD and allied conditions patients. Among COPD and allied conditions patients, major comorbidities increase risk of stroke. Therapy with mucolytic agents and combination ICS/LABA is associated with risk reduction.

Long-Term Survival and Medical Costs of Patients with Prolonged Mechanical Ventilation and Tracheostomy: A Nationwide Cohort Study

Few large-scale studies have focused on tracheostomy in patients with prolonged mechanical ventilation. This retrospective population-based study extracted data from the longitudinal National Health Insurance Research Database in Taiwan to compare long-term mortality between patients on prolonged mechanical ventilation with and without tracheostomy and their related medical expenditures. Data on newly developed respiratory failure in patients on ventilator support were extracted from 1 January 2002 to 31 December 2008. Of 10,705 patients included, 1372 underwent tracheostomy (n = 563) or translaryngeal intubation (n = 779). Overall survival of the patients with tracheostomy was followed for 5 years. Average survival was 4.98 years for the patients with tracheostomy and 5.48 years for the patients with translaryngeal intubation (not significant). Sex, age, premium-based monthly salary difference, occupation, urbanization level, chronic obstructive pulmonary disease, chronic heart failure, chronic renal disease, and cerebrovascular diseases were significantly associated with mortality for endotracheal intubation. Male sex, chronic heart failure, chronic renal disease, age ≥45 years, and low income were associated with significantly higher mortality. Although total medical expenditures were higher for the patients with tracheostomy, annual medical expenditures were not significantly different. There were no differences in long-term mortality between the two groups.

Current Knowledge of Asthma-COPD Overlap (ACO) Genetic Risk Factors, Characteristics, and Prognosis

Asthma-COPD overlap (ACO) is a newly identified phenotype of chronic obstructive airway diseases with shared asthma and COPD features. Patients with ACO are poorly defined, and some evidence suggests that they have worse health outcomes and greater disease burden than patients with COPD or asthma. Generally, there is no evidence-based and universal definition for ACO; several consensus documents have provided various descriptions of the phenotype. In addition, the mechanisms underlying the development of ACO are not fully understood. Whether ACO is a distinct clinical entity with its particular discrete genetic determinant different from asthma and COPD alone or an intermediate phenotype with overlapping genetic markers within asthma and COPD spectrum of obstructive airway disease remains unproven. This review summarizes the current knowledge of the genetic risk factors, characteristics, and prognosis of ACO.

Health expenditures of asthma-COPD overlap in Northern Jordan

Objective

To investigate the characteristics and medical expenditures of patients with Asthma- chronic obstructive pulmonary disease (COPD) overlap (ACO) compared to asthma and COPD patients.

Methods

This was a retrospective cohort study involving patients diagnosed with ACO, asthma or COPD as of January 2016. Medical records for patients attending King Abdullah University Hospital (KAUH), in northern Jordan, during the years 2015–2016 were used to identify eligible patients and all relevant clinical characteristics. Both respiratory and all-cause charges were extracted from KAUH billing system during the year 2016. Total, inpatient, outpatient, and pharmacy charges were described and compared across the three disease categories. Charges were measured in Jordanian Dinar (JOD, equal to 1.41 US Dollar).

Results

Of a total of 761, 87 ACO patients, 494 asthmatic patients and 180 COPD patients were identified and included in this study. The average total respiratory-related charges were significantly higher in patients with ACO compared to patients with asthma (601.4 versus 354.3 JODs; P value < 0.001). Average all-cause charges were higher in case of ACO and COPD compared to patients with asthma (1830.8 and 1705.4 versus 1251.7 JODs; P value < 0.001). ACO was a significant predictor of higher respiratory and all-cause related charges. Respiratory charges were also higher in older patients and those with higher disease severity.

Conclusions

ACO is a risk factor for incurring higher health expenditures in Jordan. Higher respiratory expenditures are also associated with older ages and higher disease severity.

Concurrent asthma and chronic obstructive pulmonary disease in adult ED patients: A national perspective

OBJECTIVES

Emergency department (ED) visits for Asthma and Chronic Obstructive Pulmonary Disease (COPD) are common. The designation of Asthma-COPD overlap (ACO) has been used to describe patients with features of both diseases. Studies show that ACO patients may be at increased risk of poor outcomes relative to patients with either disease alone. We sought to characterize ED visits and ED-related outcomes of patients with ACO compared to patients with Asthma or COPD alone.

METHODS

We conducted a secondary analysis of the National Hospital Ambulatory Medical Care Survey (NHAMCS, 2005-2018) characterizing ED visits in patients ≥35 years of age with Asthma Only, COPD Only or ACO. We performed univariable and multivariable analyses adjusting for demographics to assess relevant ED outcome variables.

RESULTS

From 2005 to 2018, there were an estimated 8.15, 17.78 and 0.56 million ED visits for Asthma Only, COPD Only and ACO, respectively. ACO patients were younger than COPD Only patients (mean age 50.18 versus 61.79; p < 0.001). ACO patients differed in terms of sex, race and ethnicity from patients with either disease alone. When triaged, Asthma Only (adjusted odds ratio (aOR) = 11.45; 95% confidence interval (CI), 1.20-109.38) patients were more likely to require immediate care than ACO patients. Although admission rates were comparable between groups, ACO patients had a decreased mean length of ED visit compared to both Asthma Only (p < 0.001) and COPD Only (p < 0.05) patients. COPD Only patients were less likely than ACO patients to be seen in the ED in the last 72 h (aOR = 0.22; 95% CI, 0.056-0.89), receive nebulizer therapy (aOR = 0.55; 95% CI, 0.31-0.97), bronchodilators (aOR = 0.24; 95% CI, 0.12-0.48) and systemic corticosteroids (aOR = 0.18; 95% CI, 0.091-0.35). Asthma Only patients were less likely than ACO patients to undergo any imaging (aOR = 0.55; 95% CI, 0.31-0.96) and receive antibiotics (aOR = 0.46; 95% CI, 0.23-0.93).

CONCLUSIONS

ACO patients appear to differ demographically from patients with either disease alone in the ED. After adjustment for these demographic differences, ACO patients appear to differ with respect to several ED variables, notably respiratory therapies; however, clinical outcomes including admission and mortality rates appear to be comparable between groups.

Syk-Targeted, a New 3-Arylbenzofuran Derivative EAPP-2 Blocks Airway Inflammation of Asthma-COPD Overlap in vivo and in vitro

Introduction

Asthma–chronic obstructive pulmonary (COPD) overlap (ACO) coexists with asthma and COPD syndrome characteristics, with more frequent exacerbations, heavier disease burden, higher medical utilization, and even lower quality of life. However, the ACO standard medications supported by evidence-based medicine have not yet appeared.

Methods

By using an ACO mouse model established previously and LPS-stimulated RAW264.7 macrophages in vitro, a potential therapeutic candidate, EAPP-2, was screened from derivatives of 3-arylbenzofuran, and its effect and mechanism on ACO inflammation were evaluated.

Results

EAPP-2 significantly alleviated airway inflammation in ACO mice and also inhibited the inflammatory reactions in LPS-induced RAW264.7 macrophages in vitro. Furthermore, EAPP-2 significantly inhibited the expression and phosphorylation of spleen tyrosine kinase (Syk), a common target regulating both eosinophils and neutrophils inflammation. In addition to this, EAPP-2 significantly down-regulates the expression of NF-κB, p-NF-κB, and NLRP3 in vivo and in vitro. Moreover, by using specific inhibitors in vitro, it was validated that EAPP-2 targeted on Syk and then regulated its downstream NF-κB and NLRP3.

Conclusion

EAPP-2 is shown to be a potentially useful therapeutic candidate for ACO, and its mechanism is at least partially achieved by targeting on Syk and then inhibiting NF-κB or NLRP3. Moreover, this study suggests that Syk may be a potentially effective target for ACO therapy.

Economic Burden of Asthma-Chronic Obstructive Pulmonary Disease Overlap among Older Adults in the United States

The objective of this study is to estimate the excess economic burden of Asthma-COPD Overlap (ACO) among older adults in the United States. We used a cross-sectional study design with data from a nationally representative survey of Medicare beneficiaries (Medicare Current Beneficiary Survey) linked to Medicare fee-for-service claims. Older adults with ACO had higher average total healthcare expenditures ($45,532 vs. $12,743) and higher out-of-pocket spending burden (19% vs. 8.5%) compared to those with no-asthma no-COPD (NANC). Individuals with ACO also had almost two, and 1.5 times higher expenditures compared to individuals with asthma only and COPD only, respectively. Multivariable regression models indicated that the adjusted associations of ACO to economic burden remained positive and statistically significant. In comparison with NANC, nearly three-quarters of the excess total healthcare expenditures and 83% of the out-of-pocket spending burden of older adults with ACO were explained by differences in predisposing, enabling, need, personal healthcare practices, and external factors among the two groups. The higher number of unique medications and the increased incidence of fragmented care were the leading contributors to the excess economic burden among older adults with ACO comparing to NANC individuals. Interventions that reduce the number of medications and fragmented care have the potential to reduce the excess economic burden among older adults with ACO.

Long-term prognosis of new adult-onset asthma in obese patients

Background

Obesity has been associated with poor outcomes of asthma in cross-sectional studies, but long-term effect of obesity on asthma remains unknown.

Aims

To study the effects of obesity, found at the time of diagnosis of adult-onset asthma, on 12-year prognosis by focusing on oral corticosteroid (OCS) use and respiratory-related hospital admissions.

Methods

Patients diagnosed with adult-onset asthma (n=203) were divided into three categories based on diagnostic body mass index (BMI) (<25 kg·m⁻², 25–29.9 kg·m⁻², ≥30 kg·m⁻²) and followed for 12 years as part of the Seinäjoki Adult Asthma Study. Self-reported and dispensed OCS were assessed for the 12-year period. Data on hospital admissions were analysed based on medical records.

Results

12 years after diagnosis, 86% of the patients who were obese (BMI ≥30 kg·m⁻²) at diagnosis remained obese. During the follow-up, no difference was found in weight gain between the BMI categories. During the 12-year follow-up, patients obese at diagnosis reported more frequent use of OCS courses (46.9% versus 23.1%, p=0.028), were dispensed OCS more often (81.6% versus 56.9%, p=0.014) and at higher doses (median 1350 (interquartile range 280–3180) mg versus 600 (0–1650) mg prednisolone, p=0.010) compared to normal-weight patients. Furthermore, patients who were obese had more often one or more respiratory-related hospitalisations compared to normal-weight patients (38.8% versus 16.9%, p=0.033). In multivariate logistic regression analyses, obesity predicted OCS use and hospital admissions.

Conclusions

In adult-onset asthma, patients obese at diagnosis mostly remained obese at long-term and had more exacerbations and respiratory-related hospital admissions compared to normal-weight patients during 12-year follow-up. Weight loss should be a priority in their treatment to prevent this outcome.

Obese patients with new adult-onset asthma often remain obese in the long-term and have more exacerbations and respiratory-related hospital admissions during follow-up. High priority should be given to weight loss during treatment to prevent this outcome.https://bit.ly/2G5HtRZ

Association between chronic obstructive pulmonary disease and ventricular arrhythmia: a nationwide population-based cohort study

The ventricular arrhythmia (VA)-chronic obstructive pulmonary disease (COPD) association and related risk factors remain unclear. Using 2001-2012 data from National Health Insurance Research Database, we retrospectively reviewed 71,838 patients diagnosed as having COPD and 71,838 age- and sex-matched controls. After adjustments for comorbidities, medication, urbanization level, and monthly income, patients with COPD had higher incidence rates of VA than did the controls (adjusted hazard ratio [aHR] [95% confidence interval (CI)]: 1.45 [1.25-1.68]). More hospitalization or emergency visits because of acute COPD exacerbation (aHRs [95% CIs] for first, second, and third visits: 1.28 [1.08-1.50], 1.75 [1.32-2.32], and 1.88 [1.46-2.41], respectively) and asthma-COPD overlap (aHR [95% CI]: 1.49 [1.25-1.79]) were associated with high VA risk in patients with COPD. In the multivariate analysis, heart failure (aHR [95% CI]: 2.37 [1.79-3.14]), diabetes (aHR [95% CI]:1.64 [1.29-2.08]), age ≥75 (aHR [95% CI]: 2.48 [1.68-3.67]), male (aHR [95% CI]: 1.69[1.34-2.12]), and class III antiarrhythmic drug use (aHR [95% CI]: 2.49 [1.88-3.28]) are the most significant risk factors of new onset of VA in patients with COPD.

Association of socioeconomic deprivation with asthma care, outcomes, and deaths in Wales: A 5-year national linked primary and secondary care cohort study

BACKGROUND

Socioeconomic deprivation is known to be associated with worse outcomes in asthma, but there is a lack of population-based evidence of its impact across all stages of patient care. We investigated the association of socioeconomic deprivation with asthma-related care and outcomes across primary and secondary care and with asthma-related death in Wales.

METHODS AND FINDINGS

We constructed a national cohort, identified from 76% (2.4 million) of the Welsh population, of continuously treated asthma patients between 2013 and 2017 using anonymised, person-level, linked, routinely collected primary and secondary care data in the Secure Anonymised Information Linkage (SAIL) Databank. We investigated the association between asthma-related health service utilisation, prescribing, and deaths with the 2011 Welsh Index of Multiple Deprivation (WIMD) and its domains. We studied 106,926 patients (534,630 person-years), 56.3% were female, with mean age of 47.5 years (SD = 20.3). Compared to the least deprived patients, the most deprived patients had slightly fewer total asthma-related primary care consultations per patient (incidence rate ratio [IRR] = 0.98, 95% CI 0.97-0.99, p-value < 0.001), slightly fewer routine asthma reviews (IRR = 0.98, 0.97-0.99, p-value < 0.001), lower controller-to-total asthma medication ratios (AMRs; 0.50 versus 0.56, p-value < 0.001), more asthma-related accident and emergency (A&E) attendances (IRR = 1.27, 1.10-1.46, p-value = 0.001), more asthma emergency admissions (IRR = 1.56, 1.39-1.76, p-value < 0.001), longer asthma-related hospital stay (IRR = 1.64, 1.39-1.94, p-value < 0.001), and were at higher risk of asthma-related death (risk ratio of deaths with any mention of asthma 1.56, 1.18-2.07, p-value = 0.002). Study limitations include the deprivation index being area based and the potential for residual confounders and mediators.

CONCLUSIONS

In this study, we observed that the most deprived asthma patients in Wales had different prescribing patterns, more A&E attendances, more emergency hospital admissions, and substantially higher risk of death. Interventions specifically designed to improve treatment and outcomes for these disadvantaged groups are urgently needed.

The prevalence and clinical features of chronic obstructive pulmonary disease patients with traits of asthma in Taiwan

BACKGROUND/PURPOSE

The application of the checkbox for identifying patients with traits of both chronic obstructive pulmonary disease (COPD) and asthma proposed by the 2015 Global Initiative for Asthma (GINA)/Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations has not been well studied although such identification is important in clinical practice. Thus, we aimed to investigate the prevalence and features of COPD coexistent with asthma traits diagnosed based on the 2015 GINA/GOLD strategies, and explore the gap between guidelines and routine practice in the diagnosis and pharmacological management of such condition in a COPD cohort.

METHODS

COPD subjects were enrolled retrospectively throughout Taiwan. A patient record form was completed for each participant and the data were analyzed.

RESULTS

Of 340 participants, the prevalence of COPD coexistent with traits of asthma was 39.4% and 30.3% based on guidelines and physician's judgment, respectively. Coexistent patients were characterized by blood eosinophilia, higher total immunoglobulin E (IgE) levels, preserved lung function, and the presence of gastro-esophageal reflux disease and atopic disease while total IgE level > 100 kU/L and the presence of atopic disease were predictors for coexistent patients. Gaps existed in the diagnosis (a weak agreement with kappa = 0.53) and treatment (non-adherence to the preferred therapy in 18.4% of physician-judged coexistent patients) in COPD patients with asthma traits. The exacerbation history was similar between coexistent and non-coexistent patients.

CONCLUSION

We found that measuring circulatory eosinophil and total IgE levels may raise clinicians' awareness of the presence of traits of asthma in the management of COPD.

Incidence of cancer after asthma development: 2 independent population-based cohort studies

BACKGROUND

Evidence regarding the risk of cancer development after asthma diagnosis is controversial and inconclusive.

OBJECTIVE

This study sought to determine whether asthma is associated with an increased risk for incident cancer.

METHODS

Two independent, population-based, longitudinal cohorts were examined, and estimated hazard ratios were determined using Cox regression. One group consisted of an unmatched cohort of 475,197 participants and a propensity score-matched cohort of 75,307 participants from the National Health Insurance Service-National Sample Cohort (NHIS-NSC; claims-based data from 2003 to 2015). The other group consisted of 5,440 participants from the Ansan-Ansung cohort (interview-based data from 2001 to 2014).

RESULTS

The NHIS-NSC matched cohort had 572,740 person-years of follow-up, 6,885 people with new asthma diagnoses, and 68,422 people without asthma diagnoses. Adults with asthma had a 75% greater risk of incident cancer overall. The excess risk for incident cancer was greatest during the first 2 years after asthma diagnosis, and this risk remained elevated throughout follow-up. Patients with nonatopic asthma had a greater risk of overall cancer than those with atopic asthma. A high cumulative dose of inhaled corticosteroids among asthma patients was associated with a 56% reduced risk of lung cancer, but had no effect on the risk of overall cancer. The results from the NHIS-NSC unmatched cohort and the Ansan-Ansung cohort were similar to the primary results from the NHIS-NSC matched cohort.

CONCLUSIONS

Asthma development was associated with an increased risk of subsequent cancer in 2 different Korean cohorts. Our findings provide an improved understanding of the pathogenesis of asthma and its relationship with carcinogenesis and suggest that clinicians should be aware of the higher risk of incident cancer among patients with asthma.

Associations among chronic obstructive pulmonary disease with asthma, pneumonia, and corticosteroid use in the general population

Purpose

To evaluate the association among chronic obstructive pulmonary disease (COPD) with asthma, steroid use, and pneumonia in the general population.

Methods

Using Taiwan’s National Health Insurance Research Database to identify patients with incident pneumonia, we established a COPD with asthma cohort of 12,538 patients and a COPD cohort of 25,069 patients. In both cohorts, the risk of incident pneumonia was assessed using multivariable Cox proportional hazards models.

Results

The adjusted hazard ratio (aHR) with 95% confidence interval (CI) for incident pneumonia was 2.38 (2.14, 2.66) in the COPD with asthma cohort, regardless of age, sex, comorbidities, and drug use. COPD cohort without inhaled corticosteroids (ICSs) use served as a reference. The aHR (95% CI) for COPD cohort with ICSs use was 1.34 (0.98, 1.83); that for COPD with asthma cohort without ICSs use was 2.46 (2.20, 2.76); and that for COPD with asthma cohort with ICSs use was 2.32 (1.99, 2.72). COPD cohort without oral steroids (OSs) use served as a reference; the aHR (95% CI) for COPD with asthma cohort without OSs use and with OSs use was 3.25 (2.72, 3.89) and 2.38 (2.07, 2.74), respectively.

Conclusions

The COPD with asthma cohort had a higher risk of incident pneumonia, regardless of age, sex, comorbidities, and ICSs or OSs use. COPD cohort with ICSs use did not have a notable risk of incident pneumonia. The COPD with asthma cohort had a higher risk of incident pneumonia, even without ICSs/OSs use.

The many faces of asthma-chronic obstructive pulmonary disease overlap

PURPOSE OF REVIEW

Asthma and chronic obstructive pulmonary disease (COPD) are common diseases that often overlap. The term asthma-COPD overlap (ACO) has been used to define this entity but there remain several speculations on its exact definition, impact, pathophysiology, clinical features, and management. We reviewed recent publications on ACO to obtain more insight of current knowledge and outline future needs.

RECENT FINDINGS

Criteria for ACO vary from one publication to another and the many variable features of these patients underline the need to reconsider the evaluation and approach of patients with overlapping features based on clinical traits and underlying biological mechanisms. Epidemiological studies reveal that ACO patients have generally an increased burden of illness and healthcare use in addition to poorer quality of life (QoL) compared with asthma and higher or equal to COPD. However, their long-term outcome seems better than patients with COPD alone. Various methods have been proposed to evaluate these patients but their usefulness compared to 'classical' investigation of obstructive lung diseases remains speculative and needs further evaluation. Furthermore, there are no formal studies that examined and compared the different treatment strategies of well-characterized patients with ACO as such patients are usually excluded from clinical trials.

SUMMARY

ACO is a common condition with variable features and a high burden of disease. There is no consensus on its definition, diagnostic, and clinical features and more research should be done on its optimal management and long-term outcomes.

Risk factors of chronic obstructive pulmonary disease exacerbations

Chronic Obstructive Pulmonary Disease (COPD) is a chronic respiratory disease characterised by persistent respiratory symptoms and airflow limitation. COPD has a major impact on public health, mainly because of its increasing prevalence, morbidity and mortality. The natural course of COPD is aggravated by episodes of respiratory symptom worsening termed exacerbations that contribute to disease progression. Acute Exacerbations of COPD (AECOPD) can be triggered by a multitude of different factors, including respiratory tract infections, various exposures, prior exacerbations, non-adherence to treatment and associated comorbidities. AECOPD are associated with an inexorable decline of lung function and a significantly worse survival outcome. This review will summarise the most important aspects regarding the impact of different factors that contribute to COPD exacerbations.

Global prevalence of asthma-COPD overlap (ACO) in the general population: a systematic review and meta-analysis

Background

Asthma-COPD overlap (ACO) is a term that encompasses patients with features of both asthma and COPD. To date, the global prevalence of ACO in the general population remains unknown. The objective of this study was to estimate the prevalence of ACO in the general population using a systematic review and meta-analysis.

Methods

A systematic search of ISI Web of Knowledge, MEDLINE/PubMed, and Scopus was performed up to May 2019 to identify studies reporting the prevalence of ACO. Reference lists from identified studies and relevant review articles were also searched. Eligibility criteria were studies reporting the prevalence of ACO, performed in general population, and published in English language. Pooled prevalence of ACO with 95% confidence interval (CI) was calculated using random effects Meta-analysis.

Results

A total of 27 studies were included in this meta-analysis. The Cochran Q test and I² statistics revealed substantial heterogeneity among studies. Based on the random-effects model, the pooled prevalence of ACO was 2.0% (95% CI: 1.4–2.6%) in the general population, 26.5% (95% CI: 19.5–33.6%) among patients with asthma, and 29.6% (95% CI: 19.3–39.9%) among patients with COPD. In addition, for included studies, the global prevalence of asthma-only was 6.2% (95% CI: 5.0–7.4%) and COPD-only was 4.9% (95% CI: 4.3–5.5%).

Conclusion

We estimated the global prevalence of ACO based on population-based studies and found that 2.0% of the general population is affected. However, the prevalence of ACO depends on its diagnostic criteria. Therefore, there is a vital need to better define the ACO diagnostic criteria, management and treatment. It is worth noting that the limitations of the present study include lack of studies in some region of the world and small number of studies included in the subgroup analyses.

Fungal Diseases in Taiwan-National Insurance Data and Estimation

The burden of fungal diseases based on the real-world national data is limited. This study aimed to estimate the Taiwan incident cases with selected fungal diseases in 2013 using the National Health Insurance Research Database (NHIRD) which covered 99.6% of the 23.4 million population. Over 80,000 incident cases were found and the majority were superficial infections including vulvovaginal candidiasis (477 per 100,000 adult women) and oral candidiasis (90 cases per 100,000 population). Common potentially life-threating fungal diseases were Pneumocystis pneumonia (5.35 cases per 100,000 population), candidemia (3.68), aspergillosis (2.43) and cryptococcal meningitis (1.04). Of the aforementioned cases cancer patients contributed 30.2%, 42.9%, 38.6% and 22.2%, respectively. Of 22,270 HIV-infected persons in NHIRD in 2013, four common diseases were Pneumocystis pneumonia (28.3 cases per 1000 HIV-infected patients), oral candidiasis (17.6), esophageal candidiasis (6.06) and cryptococcal meningitis (2.29). Of pulmonary aspergillosis 32.9% occurred in patients with chronic pulmonary diseases and 26.3% had a prior diagnosis of tuberculosis. There are some notable gaps related to insurance claim data. Cutaneous, urinary tract and eye fungal infections were not captured.

Statin use and Vital Organ Failure in Patients With Asthma-Chronic Obstructive Pulmonary Disease Overlap: A Time-Dependent Population-Based Study

Objective: The effects of statins on the risk of hepatic, renal, respiratory, and heart failure among patients with asthma–chronic obstructive pulmonary disease overlap (ACO) have not been reported.

Design: Time-dependent population-based study.

Setting: Patient data from 2000 to 2010 were retrieved from the Taiwan National Health Insurance Research Database.

Patients: We divided patients with ACO into cohorts of statin use (N = 1,211) and nonuse (N = 7,443).

Measurements and Main Results: The cumulative incidence rates of hepatic, renal, respiratory, and heart failure were analyzed through Cox proportional regression analysis with time-dependent variables. After adjustment for multiple confounding factors, including age, sex, comorbidities, and medications [statins, inhaled corticosteroid (ICS), or oral steroid (OS)], the adjusted hazard ratios (aHRs) [95% confidence intervals (CIs)] for hepatic, renal, respiratory, and heart failure were 0.50 (0.40–0.64), 0.49 (0.38–0.64), 0.61 (0.27–2.21), and 0.47 (0.37–0.60), respectively. The aHRs (95% CIs) for statin use with [ICS, OS] for hepatic, renal, and heart failure were [0.36 (0.20–0.66), 0.52 (0.39–0.70)]; [0.82 (0.51–1.34), 0.46 (0.33–0.63)]; and [0.66 (0.40–1.07), 0.48 (0.37–0.64)], respectively.

Conclusions: The ACO cohort with statin use exhibited lower risk of hepatic, renal, and heart failure than any other cohort, regardless of age, sex, comorbidities, or ICS or OS use. Regarding the combined use of statins and ICS, the risks of hepatic failure were lower. For the combined use of statins and OS, hepatic, renal, and heart failure were less frequent.

Association between asthma/chronic obstructive pulmonary disease overlap syndrome and healthcare utilization among the US adult population

Objectives: Asthma/chronic obstructive pulmonary disease (COPD) overlap (ACO) is a recently described phenomenon defined as the coexistence of both asthma and COPD. Both asthma and COPD are known to result in increased emergency department (ED) visits and hospitalizations, but it is unclear how the ACO population utilizes these same healthcare resources. The objective of this study was to compare healthcare utilization in the ACO population versus the general population, the asthma population and the COPD population. Methods: We conducted a pooled cross-sectional statistical analysis using the 2012-2015 National Health Interview Survey (NHIS) data. We focused on adults 18 years of age and older and excluded pregnant women. We employed an adjusted logit regression model, where the primary outcomes were dichotomous indicators on healthcare utilizations including ED visits and hospital stays. A key covariate was a four-category variable: 1) no asthma or COPD; 2) asthma only; 3) COPD only; and 4) ACO. Other covariates included age, sex, race, education level, marital status, household income level, medical insurance status, smoking status, body mass index (BMI) category, region, year and comorbidities (cancer, diabetes, hypertension, coronary heart disease and ulcer). Results: Adults with ACO were 134%, 53% and 21% more likely to have ED visits than the general population, asthma group and COPD group, respectively. For hospital stay, the ACO group was 120% and 86% more likely to be hospitalized than the general population and the asthma group respectively. In addition, adults with ACO were 61% and 130% more likely to have asthma exacerbations and asthma-related ED visits than the asthma group. Conclusions: ACO is a considerable risk factor for healthcare utilization versus the general population, the asthma population and the COPD population. Future focus should be placed on the ACO population to identify ways to reduce their healthcare utilization.

Effects of statins on anxiety and depression in patients with asthma-chronic obstructive pulmonary disease overlap syndrome

BACKGROUND

The effects of statins on anxiety and depression in patients with asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) have not been reported. This population-based study investigated these effects.

METHODS

Taiwan's National Health Insurance Research Database between 2000 and 2010. We enrolled two ACOS cohorts, one of statin users (n = 1252) and one of nonstatin users matched by age, sex, and index date (n = 7887). The cumulative incidence of anxiety and depression was analyzed using time-dependent Cox proportional regression analysis.

RESULTS

After adjustment for multiple confounding factors, including age, sex, comorbidities, and medications-statins, inhaled corticosteroids (ICSs), and oral steroids (OSs)-the ACOS cohort with statin use had significantly lower risks of anxiety and depression (anxiety: adjusted hazard ratio [aHR] = 0.34, 95% confidence interval [CI] = 0.28-0.42; depression: aHR = 0.36, 95% CI = 0.25-0.53). The aHRs (95% CIs) for statin use with ICSs or OSs were 0.32 (0.13-0.78) and 0.37 (0.24-0.57), respectively.

CONCLUSION

The ACOS cohort with statin use had lower risks of anxiety and depression, regardless of age, sex, commodities, or ICSs and OSs. The incidences of anxiety and depression were relatively low among users of statins with ICSs or OSs in the ACOS cohort.

Associations between statins and coronary artery disease and stroke risks in patients with asthma-chronic obstructive pulmonary disease overlap syndrome: A time-dependent regression study

BACKGOUND AND AIMS

We aimed at determining the effects of statin use on coronary artery disease (CAD) and stroke risks in patients with asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS).

METHODS

We retrospectively enrolled patients with ACOS treated with (N = 916) and without (N = 6338) statins. The cumulative incidence of CAD and stroke (ischemic and hemorrhagic) was analyzed through time-dependent Cox proportional regression. After adjustment for sex, age, comorbidities, inhaled corticosteroid steroid (ICS) use, and oral steroid (OS) use, we calculated the adjusted hazard ratios (aHRs) and their 95% confidence intervals (CIs) for CAD or stroke in the statin users (long-term [>600 days] and short-term [≤600 days]) compared with the non-users.

RESULTS

Among the statin users, aHRs (95% CIs) for CAD and stroke were 0.50 (0.41-0.62) and 0.83 (0.63-1.09), respectively; moreover, aHRs were 0.30 (0.09-0.99) and 0.90 (0.68-1.20) for ischemic and hemorrhagic stroke, respectively. aHRs (95% CIs) for CAD and stroke were 0.58 (0.47-0.71) and 0.93 (0.70-1.23), respectively, in the short-term users and 0.23 (0.13-0.41) and 0.42 (0.19-0.89), respectively, in the long-term users.

CONCLUSIONS

CAD risk was lower in all statin users, regardless of the duration of use, whereas ischemic stroke risk was lower only in the long-term statin users. No association was observed between hemorrhagic stroke risk and statin use.

Association between continuity of care and emergency department visits and hospitalization in senior adults with asthma-COPD overlap

OBJECTIVE

To investigate associations between continuity of care (COC) and emergency department (ED) visits and hospitalization for chronic obstructive pulmonary disease (COPD) or asthma among elderly adults with asthma-COPD overlap (ACO).

METHODS

A retrospective cohort study was performed using the Taiwan National Health Insurance research database. A total of 1141 ACO patients aged ≥65 years during 2005-2011 were observed and followed for 2 years. The Bice and Boxerman COC index (COCI) was used to evaluate COC by considering ambulatory care visits duo to COPD or asthma in the first year; ED visits and hospitalization for COPD or asthma were identified in the subsequent year, respectively. The COCI was divided into three levels (COCI < 0.3= low, 0.3 ≤ COCI<1=medium, COCI = 1=high). The Cox model was used to estimate the hazard ratio (HR) for ED visits and hospital admissions due to COPD or asthma.

RESULTS

The average COCI was 0.55. 21.3% patients received outpatient care from a single physician. Compared to patients with high COC, those with low and medium COC had a higher risk of ED visits (aHR = 2.80 and 2.69, P < .01) and admissions (aHR = 1.80 and 1.72, P < .05).

CONCLUSION

Increasing COC is beneficial for elderly patients with ACO in disease management. Policymakers could create effective pay-for-performance programs for the elderly ACO population to enhance COC and improve care outcomes.

Statin for Tuberculosis and Pneumonia in Patients with Asthma⁻Chronic Pulmonary Disease Overlap Syndrome: A Time-Dependent Population-Based Cohort Study

We investigated the effects of statins on tuberculosis (TB) and pneumonia risks in asthma⁻chronic pulmonary disease overlap syndrome (ACOS) patients. We extracted data of patients diagnosed as having ACOS during 2000⁻2010 from the Taiwan National Health Insurance Research Database and divided them into statin users and nonusers. All study participants were followed up from the index date until death, withdrawal from insurance, or TB and pneumonia occurred (31 December 2011). The cumulative TB and pneumonia incidence was analyzed using Cox proportional regression analysis with time-dependent variables. After adjustments for multiple confounding factors including age, sex, comorbidities, and use of medications [statins, inhaled corticosteroids (ICSs), or oral steroids (OSs)], statin use was associated with significantly lower TB [adjusted hazard ratio (aHR) 0.49, 95% confidence interval (CI) 0.34⁻0.70] and pneumonia (aHR 0.52, 95% CI 0.41⁻0.65) risks. Moreover, aHRs (95% CIs) for statins combined with ICSs and OSs were respectively 0.60 (0.31⁻1.16) and 0.58 (0.40⁻0.85) for TB and 0.61 (0.39⁻0.95) and 0.57 (0.45⁻0.74) for pneumonia. Thus, statin users had lower TB and pneumonia risks than did nonusers, regardless of age, sex, comorbidities, and ICS or OS use. Pneumonia risk was lower among users of statins combined with ICSs or Oss and TB risk was lower among the users of statins combined with OSs.

Asthma COPD overlap: Impact of associated comorbidities

Asthma and chronic obstructive pulmonary disease (COPD) are common chronic pulmonary conditions worldwide which often coexist. Patients with asthma COPD overlap (ACO) may have worse outcomes than those with either disease alone, for example, more respiratory symptoms and frequent exacerbations, and worse lung function. Additionally, there is a growing interest in factors that affect the disease including comorbid conditions. Indeed, recent studies have demonstrated higher rates of comorbid conditions in the ACO population, but the mechanisms behind these observations remain unclear. The objective of this review is to describe current knowledge and clinical implications of the overlapping features of asthma and COPD, and discuss the prevalence and impact of comorbidities, such as osteoporosis, cardiovascular disease, gastroesophageal reflux disease, and depression, in this subgroup of patients.

Pharmacological mechanism of roflumilast in the treatment of asthma-COPD overlap

Asthma-COPD overlap (ACO) is a type of incomplete obstructive airway disease that has a high incidence and mortality. Nevertheless, there is currently no clear definition of ACO and no effective intervention. The newly discovered phosphodiesterase-4 inhibitor, roflumilast, has shown initial efficacy for treating asthma, COPD, and ACO. The mechanism of roflumilast, however, remains unclear, and there has been no interpretation through systematic review to date. The determination of a definite mechanism of roflumilast will guide the clinician's decisions regarding medication use, standardized diagnosis, and treatment guidelines. For this reason, we have systematically reviewed the therapeutic mechanism of roflumilast for ACO and provided reference for the clinical application of roflumilast in ACO.