Exacerbation-like respiratory symptoms in individuals without chronic obstructive pulmonary disease: results from a population-based study

Self-report underestimates the frequency of the acute respiratory exacerbations of COPD but is associated with BAL neutrophilia and lymphocytosis: an observational study

RATIONALE

Research studies typically quantify acute respiratory exacerbation episodes (AECOPD) among people with chronic obstructive pulmonary disease (COPD) based on self-report elicited by survey questionnaire. However, AECOPD quantification by self-report could be inaccurate, potentially rendering it an imprecise tool for identification of those with exacerbation tendency.

OBJECTIVE

Determine the agreement between self-reported and health records-documented quantification of AECOPD and their association with airway inflammation.

METHODS

We administered a questionnaire to elicit the incidence and severity of respiratory exacerbations in the three years preceding the survey among current or former heavy smokers with or without diagnosis of COPD. We then examined electronic health records (EHR) of those with COPD and those without (tobacco-exposed persons with preserved spirometry or TEPS) to determine whether the documentation of the three-year incidence of moderate to very severe respiratory exacerbations was consistent with self-report using Kappa Interrater statistic. A subgroup of participants also underwent bronchoalveolar lavage (BAL) to quantify their airway inflammatory cells. We further used multivariable regressions analysis to estimate the association between respiratory exacerbations and BAL inflammatory cell composition with adjustment for covariates including age, sex, height, weight, smoking status (current versus former) and burden (pack-years).

RESULTS

Overall, a total of 511 participants completed the questionnaire, from whom 487 had EHR available for review. Among the 222 participants with COPD (70 ± 7 years-old; 96% male; 70 ± 38 pack-years smoking; 42% current smoking), 57 (26%) reported having any moderate to very severe AECOPD (m/s-AECOPD) while 66 (30%) had EHR documentation of m/s-AECOPD. However, 42% of those with EHR-identified m/s-AECOPD had none by self-report, and 33% of those who reported m/s-AECOPD had none by EHR, suggesting only moderate agreement (Cohen's Kappa = 0.47 ± 0.07; P < 0.001). Nevertheless, self-reported and EHR-identified m/s-AECOPD events were both associated with higher BAL neutrophils (ß ± SEM: 3.0 ± 1.1 and 1.3 ± 0.5 per 10% neutrophil increase; P ≤ 0.018) and lymphocytes (0.9 ± 0.4 and 0.7 ± 0.3 per 10% lymphocyte increase; P ≤ 0.041). Exacerbation by either measure combined was associated with a larger estimated effect (3.7 ± 1.2 and 1.0 ± 0.5 per 10% increase in neutrophils and lymphocytes, respectively) but was not statistically significantly different compared to the self-report only approach. Among the 184 TEPS participants, there were fewer moderate to very severe respiratory exacerbations by self-report (n = 15 or 8%) or EHR-documentation (n = 9 or 5%), but a similar level of agreement as those with COPD was observed (Cohen's Kappa = 0.38 ± 0.07; P < 0.001).

DISCUSSION

While there is modest agreement between self-reported and EHR-identified m/s-AECOPD, events are missed by relying on either method alone. However, m/s-AECOPD quantified by self-report or health records is associated with BAL neutrophilia and lymphocytosis.

It is high time to discard a cut-off of 0.70 in the diagnosis of COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) has traditionally been diagnosed based on the criterion of an FEV1/FVC <0.70. However, this definition has limitations as it may only detect patients with later-stage disease, when pathologic changes have become irreversible. Consequently, it potentially omits individuals with early-stage disease, in whom the pathologic changes could be delayed or reversed.

AREAS COVERED

This narrative review summarizes recent evidence regarding early-stage COPD, which may not fulfill the spirometric criteria but nonetheless exhibits features of COPD or is at risk of future COPD progression.

EXPERT OPINION

A comprehensive approach, including symptoms assessment, various physiologic tests, and radiologic features, is required to diagnose COPD. This approach is necessary to identify currently underdiagnosed patients and to halt disease progression in at- risk patients.

Low smoking exposure and development and prognosis of COPD over four decades: a population-based cohort study

BACKGROUND

A diagnosis of COPD is mainly considered in individuals with >10 pack-years of smoking. We tested the hypothesis that low smoking exposure, below the critical threshold of 10 pack-years, increases risk of COPD and leads to poor prognosis.

METHODS

We followed non-obstructed adult smokers from the Copenhagen City Heart Study for COPD, defined as a forced expiratory volume in 1 s (FEV1)/forced vital capacity <0.70 and FEV1 <80% predicted, and for related clinical outcomes. First, we followed individuals for 5 years according to baseline smoking for risk of developing COPD, and thereafter for up to four decades for severe exacerbations and death.

RESULTS

In 6098 non-obstructed smokers, 1781 (29%) developed COPD after 5 years of follow-up: 23% of individuals with <10 pack-years of smoking at baseline, 26% of those with 10-19.9 pack-years, 30% of those with 20-39.9 pack-years and 39% of those with ≥40 pack-years. During four decades of follow-up, we recorded 620 exacerbations and 5573 deaths. Compared to individuals without COPD with <10 pack‑years of smoking, multivariable adjusted hazard ratios (HRs) for exacerbations were 1.94 (95% CI 1.36-2.76) in those without COPD and ≥10 pack-years, 2.83 (95% CI 1.72-4.66) in those with COPD and <10 pack-years, 4.34 (95% CI 2.93-6.43) in those with COPD and 10-19.9 pack-years, 4.39 (95% CI 2.98-6.46) in those with COPD and 20-39.9 pack-years and 4.98 (95% CI 3.11-7.97) in those with COPD and ≥40 pack-years. Corresponding HRs for all-cause mortality were 1.20 (95% CI 1.10-1.32), 1.31 (95% CI 1.13-1.53), 1.59 (95% CI 1.40-1.79), 1.81 (95% CI 1.62-2.03) and 1.81 (95% CI 1.55-2.10).

CONCLUSION

Low smoking exposure below the critical threshold of 10 pack-years increases risk of COPD in middle-aged adults within 5 years, and these individuals have increased risk of severe exacerbation and early death over four decades.

Understanding Early COPD

Whereas COPD is currently defined as the presence of spirometric obstruction, the pathologic changes in individuals at risk including chronic mucus hypersecretion and emphysema have been recognized for centuries. At the same time, we have struggled to define criteria that would help us identify patients at an early stage, prior to the development of pulmonary function abnormality. The concept of GOLD 0 was introduced in the hopes that symptoms would help to identify those at greatest risk for progression. While symptoms are a risk factor, in particular chronic bronchitis, the term was abandoned as the majority of individuals at risk who progress to COPD do not have symptoms. Since then, the related terms pre-COPD and early COPD have been introduced. They are similar in that the term pre-COPD identifies individuals based on symptoms, physiologic, or radiographic abnormality that do not meet criteria for COPD but are clearly at risk. The term early COPD extends that concept further, focusing on individuals who have early physiologic or radiographic abnormality but at the same time are young, thereby excluding those with late mild disease who may be less likely to progress. Whereas individuals with early COPD are now being recruited for observational studies, we are still challenged with determining the best way to identify patients at risk who should undergo additional testing as well as developing specific therapies for patients with early-stage disease.

Clinical features and 1-year outcomes of chronic bronchitis in participants with normal spirometry: results from the ECOPD study in China

BACKGROUND

Evidence regarding clinical features and outcomes of individuals with non-obstructive chronic bronchitis (NOCB) remains scarce, especially in never-smokers. We aimed to investigate the clinical features and 1-year outcomes of individuals with NOCB in the Chinese population.

METHODS

We obtained data on participants in the Early Chronic Obstructive Pulmonary Disease Study who had normal spirometry (post-bronchodilator forced expiratory volume in 1 s/forced vital capacity ≥0.70). NOCB was defined as chronic cough and sputum production for at least 3 months for two consecutive years or more at baseline in participants with normal spirometry. We assessed the differences in demographics, risk factors, lung function, impulse oscillometry, CT imaging and frequency of acute respiratory events between participants with and without NOCB.

RESULTS

NOCB was present in 13.1% (149/1140) of participants with normal spirometry at baseline. Compared with participants without NOCB, those with NOCB had a higher proportion of men and participants with smoke exposure, occupational exposure, family history of respiratory diseases and worse respiratory symptoms (all p<0.05), but there was no significant difference in lung function. Never-smokers with NOCB had higher rates of emphysema than those without NOCB, but airway resistance was similar. Ever-smokers with NOCB had greater airway resistance than those without NOCB, but emphysema rates were similar. During 1-year follow-up, participants with NOCB had a significantly increased risk of acute respiratory events compared with participants who did not have NOCB, after adjustment for confounders (risk ratio 2.10, 95% CI 1.32 to 3.33; p=0.002). These results were robust in never-smokers and ever-smokers.

CONCLUSIONS

Never-smokers and ever-smokers with NOCB had more chronic obstructive pulmonary disease-related risk factors, evidence of airway disease and greater risk of acute respiratory events than those without NOCB. Our findings support expanding the criteria defining pre-COPD to include NOCB.

Bronchodilators in Tobacco-Exposed Persons with Symptoms and Preserved Lung Function

BACKGROUND

Many persons with a history of smoking tobacco have clinically significant respiratory symptoms despite an absence of airflow obstruction as assessed by spirometry. They are often treated with medications for chronic obstructive pulmonary disease (COPD), but supporting evidence for this treatment is lacking.

METHODS

We randomly assigned persons who had a tobacco-smoking history of at least 10 pack-years, respiratory symptoms as defined by a COPD Assessment Test score of at least 10 (scores range from 0 to 40, with higher scores indicating worse symptoms), and preserved lung function on spirometry (ratio of forced expiratory volume in 1 second [FEV1] to forced vital capacity [FVC] ≥0.70 and FVC ≥70% of the predicted value after bronchodilator use) to receive either indacaterol (27.5 μg) plus glycopyrrolate (15.6 μg) or placebo twice daily for 12 weeks. The primary outcome was at least a 4-point decrease (i.e., improvement) in the St. George's Respiratory Questionnaire (SGRQ) score (scores range from 0 to 100, with higher scores indicating worse health status) after 12 weeks without treatment failure (defined as an increase in lower respiratory symptoms treated with a long-acting inhaled bronchodilator, glucocorticoid, or antibiotic agent).

RESULTS

A total of 535 participants underwent randomization. In the modified intention-to-treat population (471 participants), 128 of 227 participants (56.4%) in the treatment group and 144 of 244 (59.0%) in the placebo group had at least a 4-point decrease in the SGRQ score (difference, -2.6 percentage points; 95% confidence interval [CI], -11.6 to 6.3; adjusted odds ratio, 0.91; 95% CI, 0.60 to 1.37; P = 0.65). The mean change in the percent of predicted FEV1 was 2.48 percentage points (95% CI, 1.49 to 3.47) in the treatment group and -0.09 percentage points (95% CI, -1.06 to 0.89) in the placebo group, and the mean change in the inspiratory capacity was 0.12 liters (95% CI, 0.07 to 0.18) in the treatment group and 0.02 liters (95% CI, -0.03 to 0.08) in the placebo group. Four serious adverse events occurred in the treatment group, and 11 occurred in the placebo group; none were deemed potentially related to the treatment or placebo.

CONCLUSIONS

Inhaled dual bronchodilator therapy did not decrease respiratory symptoms in symptomatic, tobacco-exposed persons with preserved lung function as assessed by spirometry. (Funded by the National Heart, Lung, and Blood Institute and others; RETHINC ClinicalTrials.gov number, NCT02867761.).

Chronic Bronchitis Affects Outcomes in Smokers without Chronic Obstructive Pulmonary Disease (COPD)

Background. Chronic bronchitis (CB) importantly affects outcomes in smokers with COPD, but the effects on smokers without COPD are less well known and less emphasized. The aim of our study was to investigate the possible effects of CB on clinical outcomes in smokers without COPD (noCOPD) and compare them with the effects in smokers with COPD (COPD). Methods. For that purpose, we studied 511 smokers, 302 with and 209 without COPD, followed for 10 years in an academic COPD ambulatory setting. Chronic bronchitis was defined as the presence of cough and sputum production for at least 3 months in each of two consecutive years. All subjects underwent clinical and functional examination with spirometry, diffusion capacity (DLco), 6-min walking test (6MWT), mMRC Dyspnoea Scale, COPD Assessment Test (CAT), and recording of annual frequency of exacerbations. All-cause mortality during follow-up was recorded. Results. 27% of noCOPD and 45% of COPD had CB. noCOPD with CB had lower FEV₁ and DLco, worse 6MWT, more dyspnoea, a higher number of exacerbations and lower survival than noCOPD without CB. CB did not affect FEV₁ decline in noCOPD but it significantly did in COPD. Conclusions. The presence of chronic bronchitis in smokers without COPD will significantly affect symptoms, quality of life, and survival, underlining the importance of recognizing the condition and managing it accordingly.

Prognosis of Patients with Chronic Obstructive Pulmonary Disease Not Eligible for Major Clinical Trials

Rationale: Randomized controlled trials only include a subset of patients with chronic obstructive pulmonary disease (COPD) fulfilling strict inclusion criteria. Thus, most patients with COPD in a real-world setting do not have the necessary evidence to support treatment effectiveness. Objectives: To test the hypotheses that most individuals with COPD in the general population are not represented in major clinical trials despite clinically significant disease with exacerbations and early death. Methods: In 105,630 adults from a Danish contemporary population-based cohort, we defined COPD as age 40 or more years, chronic respiratory symptoms, history of smoking exposure, and airflow limitation with FEV₁/FVC < 0.70. Outcomes included acute exacerbations and all-cause mortality. Symptomatic smokers without COPD were used as a reference group. Measurements and Main Results: Of all, 7,516 (7%) and 16,079 (15%) were symptomatic smokers with and without COPD. Only 44% of those with COPD were eligible for major clinical trials when applying FEV₁ < 80% predicted, smoking history of 10 or more pack-years, and no comorbid asthma as common inclusion criteria. During the median 8.9 years of follow-up, we observed 2,130 acute exacerbations and 3,973 deaths in symptomatic smokers. Compared with symptomatic smokers without COPD, multivariable-adjusted hazard ratios for exacerbations were 7.45 (95% confidence interval, 5.41-10.3) and 29.0 (21.1-39.8) in those with COPD, respectively, excluded and eligible for clinical trials. Corresponding hazard ratios for all-cause mortality were 1.21 (1.11-1.31) and 1.67 (1.54-1.81), respectively. Conclusions: More than half of individuals with COPD in the general population are excluded from major clinical trials; however, these individuals have a clinically significant disease with exacerbations and early death compared with symptomatic smokers without COPD.

Predictors of High Sputum Eosinophils in Chronic Obstructive Pulmonary Disease

BACKGROUND

Eosinophils are involved in the development of chronic obstructive pulmonary disease (COPD) and inhaled corticosteroid responsiveness. We evaluated clinical predictors of high sputum eosinophil levels in a COPD cohort in China.

METHODS

We conducted an observational, prospective, population-based, cross-sectional study. Participants were tested for COPD and underwent spirometry, computed tomography scans, and a blood test. Participants also produced induced sputum and responded to an information-gathering questionnaire. High sputum eosinophils were defined as ≥3.0%. Multivariate logistic regression was used to identify predictors of high sputum eosinophil levels.

RESULTS

We recruited 895 patients with complete and quality control data. The median percentage of sputum eosinophil abundance was 2.00% (interquartile range: 0.75-5.00) and the prevalence of COPD with high sputum eosinophils was 38.0%. Covariance analysis indicated that the high sputum eosinophil group had lower lung function, more severe emphysema, and air trapping. Multivariate logistic regression indicated that high blood eosinophil levels, severe respiratory symptoms, being a former smoker, and a family history of respiratory diseases were associated with high sputum eosinophil levels.

CONCLUSION

High blood eosinophil levels, severe respiratory symptoms, being a former smoker, and a family history of respiratory diseases may be predictors of high sputum eosinophil levels in Chinese COPD patients. High sputum eosinophils were associated with lower lung function, more emphysema, and gas trapping.

Pre-chronic obstructive pulmonary disease: a pathophysiologic process or an opinion term?

PURPOSE OF REVIEW

Current guidelines does not include current or former smokers who do not have spirometric airflow limitation in their diagnostic or therapeutic algorithms for chronic obstructive pulmonary disease (COPD). The purpose of this review is to outline the burden of respiratory morbidity in this population and to discuss the potential utility of their classification as pre-COPD.

RECENT FINDINGS

It is increasingly clear that patients with a history of exposure to cigarette smoke or other environmental pollutants may have substantial lung pathology and respiratory impairment even in the absence of airflow limitation, as detected by spirometry. Not all of these patients will develop airflow limitation, but many will have considerable respiratory morbidity and a comparable prognosis to those with classical, spirometrically defined COPD. The use of the term pre-COPD may allow for the identification of these individuals in order to target preventive and earlier therapeutic strategies.

SUMMARY

Spirometry is not adequately sensitive to identify many current and former smokers and other exposed populations with significant lung pathology and respiratory symptoms. Though the pathologic processes present in these patients differ, the earlier identification of this pre-COPD population may foster the development of more effective and disease-modifying treatments.

Defining Resilience to Smoking-related Lung Disease: A Modified Delphi Approach from SPIROMICS

Rationale: Diagnosis of chronic obstructive pulmonary disease (COPD) relies on abnormal spirometry. However, spirometry may underestimate the effects of smoking, missing smokers with respiratory disease who have minimal or no airflow obstruction. Objectives: To develop a multidimensional definition of a lung-related "resilient smoker" that is useful in research studies and then identify a resilient smoker subgroup in the SPIROMICS (SubPopulations and InteRmediate Outcome Measures In COPD Study) cohort using this definition. Methods: We performed a three-round modified Delphi survey among a panel of COPD experts to identify and reach a consensus on clinical and radiographic domains to be included in a lung-related resilient smoker definition. Consensus on domains of resilience was defined as ⩾80% of experts voting "agree" or "strongly agree" on a 5-point Likert scale. The Delphi-derived definition of resilience was applied to SPIROMICS to identify resilient smokers, whom we then characterized using known biomarkers of COPD. Results: Consensus was achieved on 6 of 12 diagnostic items, which include cough and sputum production, dyspnea, radiographic measures of emphysema and small airways disease, exacerbations, and decline in forced expiratory volume in 1 second. Although 892 SPIROMICS participants were classified as smokers with preserved lung function by spirometry, only 149 participants (16.7%) qualified as resilient smokers by our definition. Blood biomarker expression of CRP (C-reactive protein) and sTNFRSF1A (soluble tumor necrosis receptor factor1A) was lower in resilient than nonresilient smokers (P = 0.02 and P = 0.03). Conclusions: A Delphi-derived consensus definition of resilient smoker identified 83.3% of smokers with preserved spirometry as "nonresilient" based on the presence of adverse effects of smoking on the lung. Resilient smokers were biologically distinct from nonresilient smokers based on CRP measurements. Clinical trial registered with ClinicalTrials.gov (NCT01969344).

Computed tomography total airway count predicts progression to COPD in at-risk smokers

There is limited understanding of how to identify people at high risk of developing COPD. Our objective was to investigate the association between computed tomography (CT) total airway count (TAC) and incident COPD over 3 years among ever-smokers from the population-based Canadian Cohort Obstructive Lung Disease (CanCOLD) study.

CT and spirometry were acquired in ever-smokers at baseline; spirometry was repeated at 3-year follow-up. CT TAC was generated by summing all airway segments in the segmented airway tree (VIDA Diagnostics, Inc.). CT airway wall area, wall thickness for a theoretical airway with 10 mm perimeter (Pi10), and low attenuation areas below −856 HU (LAA₈₅₆) were also measured. Logistic and mixed effects regression models were constructed to determine the association for CT measurements with development of COPD and forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) decline, respectively.

Among 316 at-risk participants evaluated at baseline (65±9 years, 40% female, 18±19 pack-years), incident COPD was detected in 56 participants (18%) over a median 3.1±0.6 years of follow-up. Among CT measurements, only TAC was associated with incident COPD (p=0.03), where a 1-sd decrement in TAC increased the odds ratio for incident COPD by a factor of two. In a multivariable linear regression model, reduced TAC was significantly associated with greater longitudinal FEV₁/FVC decline (p=0.03), but no other measurements were significant.

CT TAC predicts incident COPD in at-risk smokers, indicating that smokers exhibit early structural changes associated with COPD prior to abnormal spirometry.

Computed tomography (CT) total airway count (TAC) predicts incident COPD in at-risk smokers, indicating that smokers exhibit early airway remodelling prior to abnormal spirometry and that CT TAC is a potential tool to help identify smokers at increased risk of COPDhttps://bit.ly/2UTw3I4

COPD Diagnosis: Time for Disruption

Articulating a satisfactory definition of a disease is surprisingly difficult. Despite the alarming individual, societal and economic burden of chronic obstructive pulmonary disease (COPD), diagnosis is still largely based on a physiologically dominated disease conception, with spirometrically determined airflow limitation as a cardinal feature of the disease. The diagnostic inaccuracy and insensitivity of this physiological disease definition is reviewed considering scientific developments of imaging of the respiratory system in particular. Disease must be approached as a fluid concept in response to new scientific and medical discoveries, but labelling as well as mislabelling someone as diseased, will have enormous individual, social and financial implications. Nosology of COPD urgently needs to dynamically integrate more sensitive diagnostic procedures to detect the breadth of abnormalities early in the disease process. Integration of broader information for the identification of abnormalities in the respiratory system is a cornerstone for research models of underlying pathomechanisms to create a breakthrough in research.

Investigation of the Clinical, Radiological and Biological Factors Associated with Disease Progression, Phenotypes and Endotypes of COPD in China (COMPASS): study design, protocol and rationale

COPD is heterogeneous, and its presentation varies between countries. The major COPD cohort studies have only been performed in Western populations; the disease is not well characterised in other regions. The COMPASS (Investigation of the Clinical, Radiological and Biological Factors, Humanistic and Healthcare Utilisation Burden Associated with Disease Progression, Phenotypes and Endotypes of COPD in China; NCT04853225) is a prospective, 2.5-year-long, multi-centre, longitudinal, observational study with three aims: 1) to characterise stable and exacerbation phenotypes/endotypes in terms of clinical characteristics, blood and sputum biomarkers, lung microbiome and lung imaging; 2) to understand the relevance of markers of COPD disease progression identified in Western cohorts to Chinese patients; and 3) to characterise treatment pathways and healthcare resource utilisation. COMPASS will recruit 2000 participants, of which 1700 will be in Global Initiative for Chronic Obstructive Lung Disease (GOLD) Grades I–IV (n=700, 700, 200 and 100, respectively), 180 participants with chronic bronchitis without airflow limitation and 120 never-smoker healthy controls. Study visits will be at baseline, 6, 18 and 30 months and at exacerbation. Assessments include lung function, exacerbation frequency, health status, blood biomarkers and, in a sub-cohort of 400 patients, chest high-resolution computed tomography, additional blood and sputum biomarkers, airway micro-, viral- and myco-biome, and physical activity. COMPASS will establish a unique clinical and biological dataset in a well-characterised cohort of individuals with COPD in China, with a particular focus on milder patients. As the first study of its kind attempting to understand the disease in an Asian setting, it will provide valuable insights into regional and ethnic differences in COPD.

COMPASS, a prospective, multicentre, observational study of Chinese patients with COPD, will characterise stable and exacerbation phenotypes/endotypes, treatment pathways and HRU, and investigate COPD progression biomarkers' relevance to these patientshttps://bit.ly/3dyIpf1

Chronic airflow limitation and its relation to respiratory symptoms among ever-smokers and never-smokers: a cross-sectional study

BACKGROUND

The diagnosis of chronic obstructive pulmonary disease is based on the presence of persistent respiratory symptoms and chronic airflow limitation (CAL). CAL is based on the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV₁:FVC) after bronchodilation, and FEV₁:FVC less than the fifth percentile is often used as a cut-off for CAL. The aim was to investigate if increasing percentiles of FEV₁:FVC were associated with any respiratory symptom (cough with phlegm, dyspnoea or wheezing) in a general population sample of never-smokers and ever-smokers.

METHODS

In a cross-sectional study comprising 15 128 adults (50-64 years), 7120 never-smokers and 8008 ever-smokers completed a respiratory questionnaire and performed FEV₁ and FVC after bronchodilation. We calculated their z-scores for FEV₁:FVC and defined the fifth percentile using the Global Lung Function Initiative (GLI) reference value, GLI₅ and increasing percentiles up to GLI₂₅. We analysed the associations between different strata of percentiles and prevalence of any respiratory symptom using multivariable logistic regression for estimation of OR.

RESULTS

Among all subjects, regardless of smoking habits, the odds of any respiratory symptom were elevated up to the GLI_15-20 strata. Among never-smokers, the odds of any respiratory symptom were elevated at GLI_<5 (OR 3.57, 95% CI 2.43 to 5.23) and at GLI_5-10 (OR 2.57, 95% CI 1.69 to 3.91), but not at higher percentiles. Among ever-smokers, the odds of any respiratory symptom were elevated from GLI_<5 (OR 4.64, 95% CI 3.79 to 5.68) up to GLI_≥25 (OR 1.33, 95% CI 1.00 to 1.75).

CONCLUSIONS

The association between percentages of FEV₁:FVC and respiratory symptoms differed depending on smoking history. Our results support a higher percentile cut-off for FEV₁:FVC for never-smokers and, in particular, for ever-smokers.

Advances in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder with significant morbidity and mortality. Despite its prevalence, COPD is underdiagnosed, and many patients do not receive a diagnosis until the disease is clinically advanced. Recent basic science and clinical research have focused on the early physiologic and pathobiologic changes in COPD with the hopes of improving diagnosis, providing targets for disease-modifying therapy, and identifying patients most likely to benefit from early intervention. Available treatments for COPD have grown substantially in the past 20 years with the introduction of new oral and inhaled medications as well as novel surgical and bronchoscopic procedures. This article summarizes some of the recent advances in our understanding of disease pathogenesis and treatment paradigms.

Chronic Cough and Phlegm in Subjects Undergoing Comprehensive Health Examination in Japan - Survey of Chronic Obstructive Pulmonary Disease Patients Epidemiology in Japan (SCOPE-J)

Purpose

The purpose of this study was to estimate the prevalence of subjects with chronic cough and phlegm and describe their characteristics including the presence or absence of airflow limitation among the general population in Japan.

Subjects and Methods

This was an observational cross-sectional survey targeting multiple regions of Japan. Subjects aged 40 years or above who were undergoing comprehensive health examination were recruited. The existence of chronic cough and phlegm, airflow limitation, and treatment for respiratory diseases were examined. Chronic cough and phlegm were defined as having both symptoms for at least 3 months of the year and for at least 2 consecutive years, or as receiving any treatment for chronic bronchitis at the time of recruitment. Airflow limitation was defined as forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) less than 0.7.

Results

In a total of 22,293 subjects, 380 subjects (1.7%) had chronic cough and phlegm. Among these 380 subjects, 21.8% received treatment for a respiratory disease, and 11.6% had airflow limitation. Compared to subjects without both chronic cough and phlegm but with airflow limitation, subjects with chronic cough and phlegm without airflow limitation were younger, more likely to be current smokers (39.6%), and had higher total scores on a chronic obstructive pulmonary disease (COPD) assessment test (CAT). Scores of CAT questions 1-4 (cough, phlegm, chest tightness, breathlessness, respectively) were higher in subjects with chronic cough and phlegm regardless of airflow limitation.

Conclusion

This study demonstrated that subjects identified to have chronic cough and phlegm in comprehensive health examination settings were symptomatic, while most of them did not receive any treatment for respiratory diseases and did not have airflow limitation. Screening subjects for chronic cough and phlegm in a comprehensive health examination followed by a detailed examination of screened subjects could be an effective approach for better management of chronic cough and phlegm. Smoking cessation should be included in the management, in consideration that around 40% of subjects with chronic cough and phlegm were current smokers.

Design of the Redefining Therapy in Early COPD Study

Redefining Therapy in Early COPD (RETHINC) is a 12-week multicenter, randomized, double-blind, placebo-controlled, parallel-group study to assess the efficacy and safety of indacaterol/glycopyrrolate 27.5/15.6 mcg inhaled twice daily in symptomatic current and former smokers with respiratory symptoms as defined by COPD Assessment Test (CAT) score ≥ 10 despite preserved spirometry defined by post-bronchodilator forced expiratory volume in 1 second (FEV₁) to forced vital capacity (FVC) ratio ≥ 0.70. Recruitment began in July 2017 with the goal of enrolling 580 participants. The baseline examination includes spirometry (with slow and forced maneuvers) and symptom questionnaires. A follow-up phone call at 4 weeks assesses symptoms and safety. The second and final visit at week 12 includes spirometry before and after study drug (hourly over 3 hours) and follow-up symptom questionnaires. The primary endpoint is the proportion of individuals who experience a 4-unit improvement in St George's Respiratory Questionnaire (SGRQ) score at 12 weeks without treatment failure, defined as an increase in lower respiratory symptoms necessitating treatment with active, long-acting inhaled bronchodilators, corticosteroids or antibiotics. Key secondary endpoints include the proportion of individuals with a 2-unit improvement in the CAT score; 1-unit improvement in the Baseline Dyspnea Index (BDI) and Transition Dyspnea Index (TDI), both a 4-unit improvement in SGRQ and a 1-unit improvement in BDI/TDI; and mean change in SGRQ, CAT and BDI/TDI. Other secondary endpoints include area under the curve 0-3 hours for FEV₁ after study drug, change from baseline in trough inspiratory capacity, forced expiratory flow 25%-75% of FVC (FEF_25-75) iso-volume FEF_25-75 and mean change in symptoms and rescue medication use based on daily diary. We anticipate results to be available in 2021. This paper describes the RETHINC study and explains the rationale behind it.

Factors influencing decline in quality of life in smokers without airflow obstruction: The COPDGene study

INTRODUCTION

Current and former smokers with normal spirometry and with Preserved Ratio Impaired Spirometry (PRISm) experience respiratory events similar to chronic obstructive pulmonary disease (COPD) exacerbations. Exacerbations significantly reduce quality of life (QoL) in COPD patients however the effect of respiratory exacerbations on QoL in these groups is unknown. We hypothesized that exacerbations and change in exacerbation status would predict QoL decline among normal spirometry and PRISm participants in COPDGene.

METHODS

COPDGene is a multicenter, longitudinal study in the U.S. designed to identify genetic determinants of COPD. We enrolled study subjects in Phase 1 of COPDGene and performed multivariable logistic regression models to determine independent predictors of decline in quality of life [>4 points on the St George's Respiratory Questionnaire (SGRQ)]. Separate analyses were performed for current and former smokers with normal spirometry and PRISm. Frequent exacerbator status was defined by > 2 moderate or >1 severe exacerbations in the year prior to the baseline and year 5 follow-up visits.

RESULTS

Independent predictors of QoL deterioration included current smoking, higher exacerbation frequency, and a change from infrequent to frequent exacerbation status (REF: infrequent to infrequent exacerbation status) in both groups [PRISm (OR = 3.15,95%CI, 1.67-5.94), normal spirometry (OR = 4.72,95%CI, 3.25-6.86)]. A change from frequent to infrequent exacerbation status did not lower the odds of QoL decline in either cohort.

CONCLUSION

Continued smoking and the onset of frequent exacerbations were predictors of QoL decline in smokers with normal spirometry and PRISm. Further studies are needed to identify modifiable factors associated with decline in QoL in smokers.

The effects of marijuana smoking on lung function in older people

BACKGROUND

Previous studies have associated marijuana exposure with increased respiratory symptoms and chronic bronchitis among long-term cannabis smokers. The long-term effects of smoked marijuana on lung function remain unclear.

METHODS

We determined the association of marijuana smoking with the risk of spirometrically defined chronic obstructive pulmonary disease (COPD) (post-bronchodilator forced expiratory volume in 1 s (FEV₁)/forced vital capacity ratio <0.7) in 5291 population-based individuals and the rate of decline in FEV₁ in a subset of 1285 males and females, aged ≥40 years, who self-reported use (or non-use) of marijuana and tobacco cigarettes and performed spirometry before and after inhaled bronchodilator on multiple occasions. Analysis for the decline in FEV₁ was performed using random mixed effects regression models adjusted for age, sex and body mass index. Heavy tobacco smoking and marijunana smoking was defined as >20 pack-years and >20 joint-years, respectively.

RESULTS

∼20% of participants had been or were current marijuana smokers with most having smoked tobacco cigarettes in addition (83%). Among heavy marijuana users, the risk of COPD was significantly increased (adjusted OR 2.45, 95% CI 1.55-3.88). Compared to never-smokers of marijuana and tobacco, heavy marijuana smokers and heavy tobacco smokers experienced a faster decline in FEV₁ by 29.5 mL·year^-1 (p=0.0007) and 21.1 mL·year^-1 (p<0.0001), respectively. Those who smoked both substances experienced a decline of 32.31 mL·year^-1 (p<0.0001).

INTERPRETATION

Heavy marijuana smoking increases the risk of COPD and accelerates FEV₁ decline in concomitant tobacco smokers beyond that observed with tobacco alone.

Improving Detection of Early Chronic Obstructive Pulmonary Disease

Despite being a major cause of morbidity and mortality, chronic obstructive pulmonary disease (COPD) is frequently undiagnosed. Yet the burden of disease among the undiagnosed is significant, as these individuals experience symptoms, exacerbations, and excess mortality compared to those without COPD. The U.S. Preventive Services Task Force recommends against routine screening of asymptomatic individuals with spirometry. Hence, case-finding approaches are needed. A recently developed instrument, the five-item COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk questionnaire plus peak expiratory flow, demonstrates good sensitivity and specificity for distinguishing cases from control subjects and is being studied prospectively in primary care settings to determine its impact on patient outcomes. However, finding the undiagnosed is only half the battle. Mounting evidence suggests significant COPD-like respiratory burden among individuals without airflow obstruction. Many experience dyspnea, mucus production, and exacerbation events and have emphysema and airway abnormalities on computed tomographic (CT) imaging of the chest. However, it is still unclear how to best treat these individuals and which individuals go on to develop spirometric obstruction. These challenges underline the importance of defining what constitutes "early disease." A recently proposed definition characterizes early COPD as either: 1) airflow limitation, 2) compatible CT imaging abnormalities, or 3) accelerated forced expiratory volume in 1 second decline in persons younger than 50 years and with greater than a 10 pack-year smoking history. Although it is recognized that this definition does not encompass all individuals who will develop COPD, it is an attempt to identify a group of individuals with most rapid decline to better understand mechanisms of disease development and where disease-modifying interventions are most likely to be successful. Ultimately, leveraging tools such as chest CT imaging, the electronic medical record, and machine learning algorithms may aid in the identification of such individuals.

Rethinking Chronic Obstructive Pulmonary Disease. Chronic Pulmonary Insufficiency and Combined Cardiopulmonary Insufficiency

Almost 70 years ago, Drs. Baldwin, Cournand, and Richards defined chronic pulmonary insufficiency by the presence of respiratory symptoms, radiologic evidence of pulmonary emphysema on chest radiography, and physiologic gas trapping. A decade later, airflow obstruction on spirometry was added to the definition and insufficiency became a disease. Contemporary studies are reviving the diagnostic approach described by these early luminaries, with researchers finding that symptomatic smokers with preserved spirometry have increased exacerbations and that smokers and non-smokers with normal spirometry but emphysema on chest computed tomography have increased mortality. Hence, the Baldwin-Cournand-Richards concept of disease defined by respiratory symptoms, radiologic findings, and physiology-regardless of spirometric criteria-is being rediscovered. Baldwin, Cournand, and Richards also stated that "functionally, it is obvious that the pulmonary and circulatory apparatus are one unit," and they defined combined cardiopulmonary insufficiency as chronic pulmonary insufficiency with (left or right) cardiac and pulmonary artery enlargement. They appreciated the complexity of these interactions, which include the potential role of gas trapping in heart failure with reduced ejection fraction; the impact of emphysema on blood flow in heart failure with preserved ejection fraction; multiple contributions to cor pulmonale with increased pulmonary artery pressure; and cor pulmonale parvus in emphysema; all of which may be amenable to specific therapeutic interventions. Given the complexity of heart-lung interactions originally identified by Baldwin, Cournand, and Richards and the potentially large therapeutic opportunities, large-scale studies are still warranted to find specific therapies for subphenotypes of combined cardiopulmonary insufficiency.

Prognostic significance of chronic respiratory symptoms in individuals with normal spirometry

Normal spirometry is often used to preclude airway disease in individuals with unspecific respiratory symptoms. We tested the hypothesis that chronic respiratory symptoms are associated with respiratory hospitalisations and death in individuals with normal spirometry without known airway disease.We included 108 246 randomly chosen individuals aged 20-100 years from a Danish population-based cohort study. Normal spirometry was defined as a pre-bronchodilator forced expiratory volume in 1 s/forced vital capacity ratio ≥0.70. Chronic respiratory symptoms included dyspnoea, chronic mucus hypersecretion, wheezing and cough. Individuals with known airway disease, i.e. chronic obstructive pulmonary disease and/or asthma, were excluded (n=10 291). We assessed risk of hospitalisations due to exacerbations of airway disease and pneumonia, and respiratory and all-cause mortality, from 2003 through 2018.52 999 individuals had normal spirometry without chronic respiratory symptoms and 30 890 individuals had normal spirometry with chronic respiratory symptoms. During follow-up, we observed 1037 hospitalisations with exacerbation of airway disease, 5743 hospitalisations with pneumonia and 8750 deaths, of which 463 were due to respiratory disease. Compared with individuals with normal spirometry without chronic respiratory symptoms, multivariable adjusted hazard ratios for individuals with normal spirometry with chronic respiratory symptoms were 1.62 (95% CI 1.20-2.18) for exacerbation hospitalisations, 1.26 (95% CI 1.17-1.37) for pneumonia hospitalisations, 1.59 (95% CI 1.22-2.06) for respiratory mortality and 1.19 (95% CI 1.13-1.25) for all-cause mortality. There was a positive dose-response relationship between number of symptoms and risk of outcomes. Results were similar after 2 years of follow-up, for never-smokers alone, and for each symptom separately.Chronic respiratory symptoms are associated with respiratory hospitalisations and death in individuals with normal spirometry without known airway disease.

Respiratory health and quality of life in young exclusive, habitual smokers - a comparison of waterpipe smokers, cigarette smokers and non-smokers

Purpose

Waterpipe (WP) use has become a global trend in young populations. However, there are few well-controlled studies focusing specifically on the chronic effects of exclusive WP use on young adults’ respiratory health. We sought to compare in young adults the burden of respiratory symptoms in regular WP smokers (WPS) relative to regular cigarette smokers (CS, positive controls) and non-smokers (negative controls); and to evaluate differences in health-related quality of life between the three groups.

Method

We implemented a cross-sectional survey in college campuses across four countries (Egypt, Jordan, Morocco and Oman). Purposive sampling was employed to identify habitual (regular) healthy WPS (smoked 3 or more WP per week for 3 or more years); CS (smoked 5 or more cigarettes daily for 3 or more years); and non-smokers. Respiratory symptoms were assessed using the European Community Respiratory Health Survey and the American Thoracic Society and the Division of Lung Diseases Questionnaire. Health-related quality of life was measured using the Short-Form 12. Demographic, environmental and lifestyle factors also were measured.

Result

The analytic sample included 135 WPS, 303 CS, and 300 non-smokers. Either tobacco group had significantly greater proportions of males than the non-smoker group. A significantly lower proportion of non-smokers (than either tobacco group) was overweight or obese. Average numbers of reported respiratory symptoms were 5.1, 5.8, and 2.9 in WPS, CS, and non-smokers, respectively. In multivariable regressions controlling for environmental exposures, body mass index, and physical activity, WPS and CS exhibited significantly higher rates of respiratory symptoms than non-smokers (1.6 times greater and 1.9 times greater rate of respiratory symptoms than non-smokers, respectively). Non-smokers reported significantly higher scores for general health relative to either WPS or CS.

Conclusion

Relative to their young non-smoking counterparts, young habitual WPS exhibit a significant burden of respiratory symptoms that is comparable to that observed with CS. Young WPS (and CS), despite their age, may be well on their way to developing respiratory disease.

Normal lung attenuation distribution and lung volume on computed tomography in a Chinese population

Backgroud and objectives: Although lung attenuation distribution and lung volume on computed tomography (CT) have been widely used in evaluating COPD and interstitial lung disease, there are only a few studies regarding the normal range of these indices, especially in Chinese subjects. We aimed to describe the normal range of lung attenuation distribution and lung volume based on CT.

Methods: Subjects with normal lung function and basically normal chest CT findings (derivation group) at Ruijin Hospital, Shanghai (from January 2010 to June 2014) were included according to inclusion and exclusion criteria. The range of the percentage of lung volume occupied by low attenuation areas (LAA%), percentile of the histogram of attenuation values (Perc n), and total lung volume were analyzed. Relationships of these measures with demographic variables were evaluated. Participants who underwent chest CT examination for disease screening and had basically normal CT findings served as an external validation group.

Results: The number of subjects in the derivation group and external validation groups were 564 and 1,787, respectively. Mean total lung volumes were 4,468±1,271 mL and 4,668±1,192 mL, and median LAA%(-950 HU) was 0.19 (0.03–0.43) and 0.17 (0.01–0.41), in the derivation and external validation groups, respectively. Reference equations for lung volume and attenuation distribution (LAA% using -1,000–210 HU, Perc 1 to Perc 98) were generated: Lung volume (mL) = -1.015 *10^4+605.3*Sex (1= male, 0= female)+92.61*Height (cm) –12.99*Weight (kg) ±1766; LAA% (-950 HU)=[0.2027+0.05926*Sex (1= male, 0= female) –4.111*10^-3*Weight (kg) +4.924*10^-3*Height (cm) +8.504*10^-4*Age]^7.341–0.05; Upper limit of normal range: [0.2027+0.05926*Sex-4.111*10^-3*Weight+4.924*10^-3*Height+8.504*10^-4*Age+0.1993]^7.341–0.05.

Conclusion: This large population-based retrospective study demonstrated the normal range of LAA%, Perc n, and total lung volume measured on CT scans among subjects with normal lung function and CT findings. Reference equations are provided.

Weighing the evidence for pharmacological treatment interventions in mild COPD; a narrative perspective

There is increasing focus on understanding the nature of chronic obstructive pulmonary disease (COPD) during the earlier stages. Mild COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 1 or the now-withdrawn GOLD stage 0) represents an early stage of COPD that may progress to more severe disease. This review summarises the disease burden of patients with mild COPD and discusses the evidence for treatment intervention in this subgroup.

Overall, patients with mild COPD suffer a substantial disease burden that includes persistent or potentially debilitating symptoms, increased risk of exacerbations, increased healthcare utilisation, reduced exercise tolerance and physical activity, and a higher rate of lung function decline versus controls. However, the evidence for treatment efficacy in these patients is limited due to their frequent exclusion from clinical trials. Careful assessment of disease burden and the rate of disease progression in individual patients, rather than a reliance on spirometry data, may identify patients who could benefit from earlier treatment intervention.

Association of Symptoms of Obstructive Lung Disease and All-Cause Mortality in Older Adult Smokers

OBJECTIVES

This study aims to investigate the impact of respiratory symptoms in current and former smokers with and without obstructive lung disease (OLD) on all-cause mortality.

DESIGN

Secondary analysis in a prospective cohort (the Health, Aging and Body Composition study).

SETTING

Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Black and white men and women with a history of current and former smoking (N = 596; 63% male and 37% female) aged 70-79 years followed for 13 years. Participants were categorized into 4 mutually exclusive groups based on symptom profile and forced expiratory volume in the 1st second to forced vital capacity ratio. The groups were Less Dyspnea-No OLD (N = 196), More Dyspnea-No OLD (N = 104), Less Dyspnea-With OLD (N = 162), and More Dyspnea-With OLD (N = 134).

MEASUREMENTS

All-cause mortality.

RESULTS

Overall, 53% in Less Dyspnea-No OLD, 63% in More Dyspnea-No OLD, 67% in Less Dyspnea-With OLD, and 84% in More Dyspnea-With OLD died within the 13- year follow up period (log-rank χ²  = 44.4, P < .0001). The hazard ratio was highest for participants with OLD, both with (HR =1.91, 95% CI 1.44 - 2.54; P < .0001) and without dyspnea (HR = 1.52, 95% CI 1.15 - 2.02; p = .004). Participants without OLD but with dyspnea had a similar risk of death to subjects who had OLD but fewer symptoms.

CONCLUSIONS

OLD is associated with high risk of death with different risk profiles based on symptom group. Patients with symptoms of shortness of breath without OLD should be considered an at-risk group given their similar mortality to those with OLD with minimal symptoms. J Am Geriatr Soc 67:2116-2122, 2019.

SF-6D utility scores of smokers and ex-smokers with or without respiratory symptoms attending primary care clinics

Introduction

The aim of this paper is to find out generic preference-based Short-Form 6 Dimensions (SF-6D) utility scores of smokers and ex-smokers with varying cigarette exposure, with and without respiratory symptoms.

Methods

Seven hundred thirty one people aged ≥30 with a history of smoking who attended 5 public primary care clinics completed a cross-sectional survey using SF-6D utility score, Breathlessness, Cough, and Sputum Scale (BCSS©) and office spirometry.

Results

Most of the subjects were men (92.5%) in an older age group (mean age 62.2 ± 11.7 years). About half of them (48.3%) were current smokers while the other half (51.7%) were ex-smokers. More than half of them (54.2%) reported mild respiratory symptoms (mean BCSS score 0.95 ± 1.12). The most common symptoms were sputum (45.1%), followed by cough (34.2%) and breathlessness (6.0%). The SF-6D overall utility score was 0.850 ± 0.106. The subjects reported significantly lower SF-6D scores when they had breathlessness (0.752 ± 0.138; p = < 0.001), cough (0.836 ± 0.107; p = 0.007), sputum (0.838 ± 0.115; p = 0.004) or any of the above symptom (0.837 ± 0.113; p < 0.001). In both groups of current smokers and ex-smokers, there was no statistically significant difference in the scores among light, moderate or heavy smokers. In the Tobit regression model of factors affecting SF-6D utility score, subjects who reported more respiratory symptoms (i.e. higher BCSS©) had lower SF-6D scores (B = − 0.018 ± 0.007, p < 0.001), while men had higher SF-6D scores than women (B = 0.037 ± 0.031, p = 0.019). Subjects who attended middle or high school had higher SF-6D score than those attended the University or above. The presence of airflow obstruction was not associated with the score.

Conclusions

The study yielded SF-6D utility scores of smokers and ex-smokers with different reported cigarette exposure, which could be useful in future clinical studies and cost-effectiveness analysis.

What is a COPD exacerbation? Current definitions, pitfalls, challenges and opportunities for improvement

Chronic obstructive pulmonary disease (COPD) is a chronic illness that can be periodically punctuated by exacerbations, characterised by acute worsening of symptoms, including increased dyspnoea, cough, sputum production and sputum purulence. COPD exacerbations are common and have important clinical and economic consequences, including lost work productivity, increased utilisation of healthcare resources, temporary or permanent reductions in lung function and exercise capacity, hospitalisation, and sometimes death. Over the past two decades, clinicians and researchers have broadened their treatment goals for COPD to extend beyond improving lung function and symptoms, and have begun to address the importance of preventing and reducing exacerbations. However, despite the best efforts of clinicians and guideline committees, current definitions of COPD exacerbations are imperfect and fraught with problems. The cardinal symptoms of a COPD exacerbation are nonspecific and can result from acute cardiorespiratory illnesses other than COPD. A proposed definition, which may be more specific than current definitions, suggests that COPD exacerbation be defined as an acute or subacute worsening of dyspnoea (≥5 on a visual analogue scale that ranges from 0 to 10) sometimes but not necessarily accompanied by increased cough, sputum volume and/or sputum purulence. Necessary laboratory criteria for an exacerbation include oxygen desaturation ≤4% below that of stable state, elevated levels of circulating blood neutrophils or eosinophils (≥9000 neutrophils·mm^-3 or ≥2% blood eosinophils) and elevated C-reactive protein (≥3 mg·L^-1), without evidence of pneumonia or pulmonary oedema on chest radiography and with negative laboratory test results for other aetiologies. Herein, we discuss the current state of the art with respect to how we define COPD exacerbations, associated pitfalls and challenges, and opportunities for improvement.

Harmonization of Respiratory Data From 9 US Population-Based Cohorts: The NHLBI Pooled Cohorts Study

Chronic lower respiratory diseases (CLRDs) are the fourth leading cause of death in the United States. To support investigations into CLRD risk determinants and new approaches to primary prevention, we aimed to harmonize and pool respiratory data from US general population-based cohorts. Data were obtained from prospective cohorts that performed prebronchodilator spirometry and were harmonized following 2005 ATS/ERS standards. In cohorts conducting follow-up for noncardiovascular events, CLRD events were defined as hospitalizations/deaths adjudicated as CLRD-related or assigned relevant administrative codes. Coding and variable names were applied uniformly. The pooled sample included 65,251 adults in 9 cohorts followed-up for CLRD-related mortality over 653,380 person-years during 1983-2016. Average baseline age was 52 years; 56% were female; 49% were never-smokers; and racial/ethnic composition was 44% white, 22% black, 28% Hispanic/Latino, and 5% American Indian. Over 96% had complete data on smoking, clinical CLRD diagnoses, and dyspnea. After excluding invalid spirometry examinations (13%), there were 105,696 valid examinations (median, 2 per participant). Of 29,351 participants followed for CLRD hospitalizations, median follow-up was 14 years; only 5% were lost to follow-up at 10 years. The NHLBI Pooled Cohorts Study provides a harmonization standard applied to a large, US population-based sample that may be used to advance epidemiologic research on CLRD.

Significant predictors of medically diagnosed chronic obstructive pulmonary disease in patients with preserved ratio impaired spirometry: a 3-year cohort study

Background

Preserved ratio impaired spirometry (PRISm) is an incompletely understood respiratory condition. We investigated the incidence and significant predictive factors of chronic obstructive pulmonary disease (COPD) in PRISm patients.

Methods

From 11,922 subjects registered in the Korea National Health and Nutrition Examination Survey, never or light smokers, young subjects, and those already medically diagnosed with COPD (defined by ICD-10 code and prescribed medication) were excluded. The 2666 remaining subjects were categorized into PRISm (normal forced expiratory volume in the first second [FEV₁]/force vital capacity [FVC] [≥ 0.7] and low FEV₁ (< 80%); n = 313); normal (n = 1666); and unrevealed COPD groups (FEV₁/FVC ratio <  0.7; n = 687). These groups were compared using matched Health Insurance Review and Assessment Service data over a 3-year follow-up.

Results

COPD incidence in PRISm patients (17/1000 person-year [PY]) was higher than that in normal subjects (4.3/1000 PY; P <  0.001), but lower than that in unrevealed COPD patients (45/1000 PY; P < 0.001). PRISm patients visited hospitals, took COPD medication, and incurred hospitalization costs more frequently than normal subjects, but less frequently than unrevealed COPD patients. In the overall sample, age, FVC, FEV₁, dyspnea, and wheezing were significant predictors of COPD, but in PRISm patients, only age (OR, 1.14; P = 0.002) and wheezing (OR, 4.56; P = 0.04) were significant predictors.

Conclusion

PRISm patients are likely to develop COPD, and should be monitored carefully, especially older patients and those with wheezing, regardless of lung function.

The diagnostic performance of patient symptoms in screening for COPD

It is recommended that screening for COPD be restricted to symptomatic individuals, but supporting evidence is lacking. We determined the performance of wheeze, cough, phlegm, and dyspnea in discriminating COPD versus non-COPD in a population-based sample of 1332 adults. Area Under the Receiver Operating Curves (AUC) indicated that symptoms had modest performance whether assessed individually (AUCs 0.55–0.62), or in combination (AUC for number of symptoms as the predictor 0.64). AUC improved with the inclusion of multiple other factors (AUC 0.71). Restricting screening to symptomatic individuals is unlikely to substantially improve the yield of general population screening for undiagnosed COPD.

The clinical implications of tests confirming COPD in subjects hospitalized with exacerbations

BACKGROUND

The diagnosis of COPD in patients hospitalized for AECOPD can be confirmed by spirometry showing obstruction or radiographs showing emphysema. The evidence for COPD is sometimes absent or contradicts this diagnosis. The inaccurate attribution of the exacerbation to COPD can lead to suboptimal care and worse outcome.

OBJECTIVES

We determined if the presence of tests that confirm the diagnosis of COPD has any implications on the course of the hospitalization and readmission rate.

METHODS

We selected subjects hospitalized between 2012 and 2014 for AECOPD. We divided them into four hierarchical, mutually exclusive groups based on the presence of tests that confirm the diagnosis of COPD: spirometry (COPD_SPIRO), radiology (COPD_RAD), clinical diagnosis (COPD_CLIN), and no COPD by spirometry (NotCOPD). We compared the presentation, hospital course, outcome, and readmission rate between the four groups.

RESULTS

We identified 974 subjects: COPD_SPIRO 22%, COPD_RAD 24%, COPD_CLIN 46% and 7% NotCOPD. The vital signs, use of respiratory support, admission to the MICU, and length of stay were similar between the groups. The age, gender, BMI, presence of comorbidities, and readmission rate were different between the groups. The NotCOPD group had the highest BMI (38 kg/m²), comorbidities, and 30-day all-cause readmission (17%). Logistic regression showed that serum creatinine and presence of any comorbidity were the independent predictors of 30-day all-cause readmission.

CONCLUSION

COPD was confirmed by spirometry or radiographs in half of the subjects hospitalized for AECOPD. The presence of confirmation did not influence the hospital course. The presence of confirmation was associated with different readmission rate, but was accounted for by the presence of comorbidities.

Excess risk of major vascular diseases associated with airflow obstruction: a 9-year prospective study of 0.5 million Chinese adults

Background

China has high COPD rates, even among never-regular smokers. Little is known about nonrespiratory disease risks, especially vascular morbidity and mortality after developing airflow obstruction (AFO) in Chinese adults.

Objective

We aimed to investigate the prospective association of prevalent AFO with major vascular morbidity and mortality.

Materials and methods

In 2004-2008, a nationwide prospective cohort study recruited 512,891 men and women aged 30-79 years from 10 diverse localities across China, tracking cause-specific mortality and coded episodes of hospitalization for 9 years. Cox regression yielded adjusted HRs for vascular diseases comparing individuals with spirometry-defined prevalent AFO at baseline to those without.

Results

Of 489,382 participants with no vascular disease at baseline, 6.8% had AFO, with prevalence rising steeply with age. Individuals with prevalent AFO had significantly increased vascular mortality (n=1,429, adjusted HR 1.29, 95% CI 1.21-1.36). There were also increased risks of hemorrhagic stroke (n=823, HR 1.18, 95% CI 1.09-1.27), major coronary events (n=635, HR 1.33, 95% CI 1.22-1.45), and heart failure (n=543, HR 2.19, 95% CI 1.98-2.41). For each outcome, the risk increased progressively with increasing COPD severity and persisted among never-regular smokers.

Conclusion

Among adult Chinese, AFO was associated with significantly increased risks of major vascular morbidity and mortality. COPD management should be integrated with vascular disease prevention and treatment programs to improve long-term prognosis.

Health Services Burden of Undiagnosed and Overdiagnosed COPD

BACKGROUND

Misdiagnosis of COPD is common. The goal of this study was to quantify the health services burden of undiagnosed and overdiagnosed COPD in a real-world, North American population.

METHODS

A population-based cohort study was conducted. Presence of COPD using spirometry was ascertained in randomly selected adults aged ≥ 40 years from Ontario, Canada, who participated in the Canadian Obstructive Lung Disease study. The presence of physician-diagnosed COPD was ascertained for the same subjects by using linked health administrative data. Participants were then categorized into four groups: correctly diagnosed, undiagnosed, overdiagnosed, and no COPD according to either criteria. Age- and sex-standardized rates of hospitalizations, ED visits, and ambulatory care visits in each group were determined and compared.

RESULTS

Of 1,403 participants, 13.7% had undiagnosed COPD, 5.1% were overdiagnosed, and 3.7% had correctly diagnosed COPD. Subjects with overdiagnosed COPD had significantly higher rates of hospitalizations, ED visits, and ambulatory care visits, and subjects with moderate to severe undiagnosed COPD had higher rates of hospitalizations, than subjects in the non-COPD population.

CONCLUSIONS

Undiagnosed and overdiagnosed COPD contribute to significant health care burden. Given that misdiagnosed COPD was fivefold more common than correctly diagnosed COPD, these findings point to a substantial misdiagnosis-associated burden of disease that might be prevented, at least in part, with a correct diagnosis.

Classifying Chronic Lower Respiratory Disease Events in Epidemiologic Cohort Studies

RATIONALE

One in 12 adults has chronic obstructive pulmonary disease or asthma. Acute exacerbations of these chronic lower respiratory diseases (CLRDs) are a major cause of morbidity and mortality. Valid approaches to classifying cases and exacerbations in the general population are needed to facilitate prevention research.

OBJECTIVES

To assess the feasibility, reproducibility, and performance of a protocol to identify CLRD cases and exacerbations triggering emergency department (ED) visits or hospitalizations in cohorts of patients derived from general populations of adults.

METHODS

A protocol was developed to classify CLRD cases and severe exacerbations on the basis of review of medical records. ED and inpatient medical records were ascertained prospectively in the Hispanic Community Health Study/Study of Latinos, and inpatient records were retrospectively identified by administrative codes in the Multi-Ethnic Study of Atherosclerosis. "Probable" exacerbations were defined as a physician's diagnosis of CLRD with acute respiratory symptoms. "Highly probable" exacerbations additionally required systemic corticosteroid therapy, and "definite" exacerbations required airflow limitation or evidence of CLRD on imaging studies. Adjudicated results were compared with CLRD cases identified by spirometry and self-report, and with an administrative definition of exacerbations.

MEASUREMENTS AND MAIN RESULTS

Protocol-based classification was completed independently by two physicians for 216 medical records (56 ED visits and 61 hospitalizations in the Hispanic Community Health Study/Study of Latinos; 99 hospitalizations in the Multi-Ethnic Study of Atherosclerosis). Reviewer disagreement occurred in 2-5% of cases and 4-8% of exacerbations. Eighty-nine percent of records were confirmed as at least probable CLRD cases. Fifty-six percent of confirmed CLRD cases had airflow limitation on the basis of baseline study spirometry. Of records that described CLRD as the primary discharge diagnosis code, an acute exacerbation was confirmed as at least probable for 96% and as highly probable or definite for 77%. Only 50% of records with CLRD as a secondary code were confirmed, although such records accounted for over half of all confirmed exacerbations.

CONCLUSIONS

CLRD cases and severe exacerbations without preceding documentation of airflow limitation are identified frequently in population-based cohorts of persons. A primary discharge diagnosis of CLRD is specific but insensitive for defining exacerbations. Protocol-based classification of medical records may be appropriate to supplement and to validate identification of CLRD cases and exacerbations in general population studies. Clinical trials registered with www.clinicaltrials.gov (NCT00005487 and NCT02060344).

[Over-diagnosis of chronic obstructive pulmonary disease in Primary Care. Prevalence and determining factors]

INTRODUCTION

COPD under-diagnosis is common in Primary Health Care medicine, due to the low use of spirometry, but there is less information about over-diagnosis of the disease in patients that have a clinical diagnosis of COPD.

OBJECTIVE

The main objective of the study was to investigate the prevalence of COPD over-diagnosis in Primary Care medicine. Secondary objectives were to determine the factors associated with an incorrect clinical diagnosis of COPD and to analyse whether the pharmacological treatment is different for patients with correct or incorrect diagnosis.

METHOD

A prospective, observational, cross-sectional study was conducted using the spirometry results of 206 patients with a clinical diagnosis of COPD, with no prior lung function testing, and who were treated with inhaled therapy. Characteristics and treatment of patients with a correct or incorrect COPD diagnosis were compared.

RESULTS

The prevalence of COPD over-diagnosis was 42.7% in the study population. Factors associated with an incorrect diagnosis were female sex (P<.0001), obesity (P=.009), absence of smoking history (P<.0001), lower age (P=.001), and less severe dyspnoea (P=.001). Long-acting muscarinic agents were more frequently prescribed to patients with a correct COPD diagnosis. There were no other differences regarding inhaled therapies between both groups.

CONCLUSIONS

Over-diagnosis is a frequent phenomenon in patients with a clinical diagnosis of COPD managed in Primary Care medicine. There are different features between patients with a correct and incorrect diagnosis. Spirometry is an essential tool to reduce COPD over-diagnosis.

Human β-defensin-2 production upon viral and bacterial co-infection is attenuated in COPD

Viral-bacterial co-infections are associated with severe exacerbations of COPD. Epithelial antimicrobial peptides, including human β-defensin-2 (HBD-2), are integral to innate host defenses. In this study, we examined how co-infection of airway epithelial cells with rhinovirus and Pseudomonas aeruginosa modulates HBD-2 expression, and whether these responses are attenuated by cigarette smoke and in epithelial cells obtained by bronchial brushings from smokers with normal lung function or from COPD patients. When human airway epithelial cells from normal lungs were infected with rhinovirus, Pseudomonas aeruginosa, or the combination, co-infection with rhinovirus and bacteria resulted in synergistic induction of HBD-2 (p<0.05). The combination of virus and flagellin replicated this synergistic increase (p<0.05), and synergy was not seen using a flagella-deficient mutant Pseudomonas (p<0.05). The effects of Pseudomonas aeruginosa were mediated via interactions of flagellin with TLR5. The effects of HRV-16 depended upon viral replication but did not appear to be mediated via the intracellular RNA helicases, retinoic acid-inducible gene-I or melanoma differentiation-associated gene-5. Cigarette smoke extract significantly decreased HBD-2 production in response to co-infection. Attenuated production was also observed following co-infection of cells obtained from healthy smokers or COPD patients compared to healthy controls (p<0.05). We conclude that co-exposure to HRV-16 and Pseudomonas aeruginosa induces synergistic production of HBD-2 from epithelial cells and that this synergistic induction of HBD-2 is reduced in COPD patients. This may contribute to the more severe exacerbations these patients experience in response to viral-bacterial co-infections.

Respiratory Symptoms Items from the COPD Assessment Test Identify Ever-Smokers with Preserved Lung Function at Higher Risk for Poor Respiratory Outcomes. An Analysis of the Subpopulations and Intermediate Outcome Measures in COPD Study Cohort

RATIONALE

Ever-smokers without airflow obstruction scores greater than or equal to 10 on the COPD Assessment Test (CAT) still have frequent acute respiratory disease events (exacerbation-like), impaired exercise capacity, and imaging abnormalities. Identification of these subjects could provide new opportunities for targeted interventions.

OBJECTIVES

We hypothesized that the four respiratory-related items of the CAT might be useful for identifying such individuals, with discriminative ability similar to CAT, which is an eight-item questionnaire used to assess chronic obstructive pulmonary disease impact, including nonrespiratory questions, with scores ranging from 0 to 40.

METHODS

We evaluated ever-smoker participants in the Subpopulations and Intermediate Outcomes in COPD Study without airflow obstruction (FEV1/FVC ≥0.70; FVC above the lower limit of normal). Using the area under the receiver operating characteristic curve, we compared responses to both CAT and the respiratory symptom-related CAT items (cough, phlegm, chest tightness, and breathlessness) and their associations with longitudinal exacerbations. We tested agreement between the two strategies (κ statistic), and we compared demographics, lung function, and symptoms among subjects identified as having high symptoms by each strategy.

RESULTS

Among 880 ever-smokers with normal lung function (mean age, 61 yr; 52% women) and using a CAT cutpoint greater than or equal to 10, we classified 51.8% of individuals as having high symptoms, 15.3% of whom experienced at least one exacerbation during 1-year follow-up. After testing sensitivity and specificity of different scores for the first four questions to predict any 1-year follow-up exacerbation, we selected cutpoints of 0-6 as representing a low burden of symptoms versus scores of 7 or higher as representing a high burden of symptoms for all subsequent comparisons. The four respiratory-related items with cutpoint greater than or equal to 7 selected 45.8% participants, 15.6% of whom experienced at least one exacerbation during follow-up. The two strategies largely identified the same individuals (agreement, 88.5%; κ = 0.77; P < 0.001), and the proportions of high-symptoms subjects who had severe dyspnea were similar between CAT and the first four CAT questions (25.9% and 26.8%, respectively), as were the proportions reporting impaired quality of life (66.9% and 70.5%, respectively) and short walking distance (22.4% and 23.1%, respectively). There was no difference in area under the receiver operating characteristic curve to predict 1-year follow-up exacerbations (CAT score ≥10, 0.66; vs. four respiratory items from CAT ≥7 score, 0.65; P = 0.69). Subjects identified by either method also had more depression/anxiety symptoms, poor sleep quality, and greater fatigue.

CONCLUSIONS

Four CAT items on respiratory symptoms identified high-risk symptomatic ever-smokers with preserved spirometry as well as the CAT did. These data suggest that simpler strategies can be developed to identify these high-risk individuals in primary care.

Asthma and smoking-induced airway disease without spirometric COPD

Due to the high prevalence rates of cigarette smoking and asthma, current and ex-smokers frequently develop chronic airway disease without spirometric evidence of chronic obstructive pulmonary disease (COPD), either alone or associated with asthma. This review considers the classification, clinical outcomes, inflammatory and imaging variables, phenotypes, and management of current and ex-smokers with airway disease without COPD, focusing on overlaps in those with and without asthma. These individuals have more respiratory symptoms, worse quality of life, increased exacerbation rates, reduced lung function and more comorbidities than never-smokers with asthma or healthy never-smokers. As well as clinical features, airway inflammatory and structural changes in smoking-induced airway disease without COPD overlap with those found in smokers with asthma. Cigarette smoking is associated with worse clinical outcomes in some phenotypes of asthma. Management involves public health measures to control exposure to tobacco smoke, personal advice on smoking cessation and the use of appropriate targeted therapies, although evidence is limited on their effectiveness. Understanding the mechanisms, natural history and management of current and ex-smokers with asthma and smoking-induced airway disease without COPD is a priority for future research.