Dyspnea in Chronic Obstructive Pulmonary Disease: Expert Assessment of Management in Clinical Practice

Abstract

Chronic obstructive pulmonary disease (COPD) is a multifaceted lung condition characterized by persistent airflow limitation that leads to chronic symptoms, including dyspnea, cough, and exacerbations. To date, a major focus for the assessment and management of COPD has been on mitigating exacerbations. However, dyspnea is the most common symptom of COPD and is responsible for substantial negative effects on patients’ quality of life. Dyspnea is also a substantial contributor to the symptoms associated with acute exacerbations in COPD. Though a portion of the current recommendations for the assessment and management of COPD are dedicated to dyspnea treatment intervention strategies, there remains a need for improvement in communication between healthcare practitioners and their patients regarding the understanding of dyspnea and the implementation of key nonpharmacologic and pharmacologic treatment options. This clinical commentary outlines practical considerations and recommendations for the real-world assessment and management of dyspnea in COPD, including underlying causes, patient and healthcare provider dialogue, measurement of severity, and management strategies.

Plain Language Summary

Chronic obstructive pulmonary disease, or COPD, is a long-term disease of the lungs that can cause several symptoms, including cough, flare-ups (times when symptoms suddenly worsen, also known as exacerbations), and breathlessness (also referred to as dyspnea). Medications and other therapies for COPD mainly focus on reducing how often exacerbations happen or how bad they are. However, dyspnea is a major problem for patients with COPD, often making it difficult to live their everyday lives. Moreover, dyspnea is commonly seen in patients with COPD when they have an exacerbation. Although current recommendations for the management of COPD include strategies to help with dyspnea, patients may still need more information about their dyspnea and how to manage it. This could be due to several factors, including a disconnect in the dialogue patients have with their doctors regarding their experience of dyspnea. This article shares practical insights from respiratory doctors on how they help patients with COPD manage their dyspnea and provides an overview of the causes, measurement, and management of dyspnea.

Key Summary Points

Dyspnea is the most common symptom of chronic obstructive pulmonary disease (COPD) and is a major cause of disability associated with COPD.

Dyspnea among patients with COPD can arise from non-COPD pulmonary etiologies (e.g., pulmonary hypertension or bronchiectasis with chronic infections), cardiac etiologies (e.g., congestive heart failure, diastolic dysfunction, or arrhythmias), or deconditioning.

Clinical assessment of dyspnea in COPD includes thorough history, physiologic testing (e.g., pulmonary function testing, echocardiography, and 6-min walk test), and healthcare practitioner (HCP) assessment of patient-reported outcomes.

Management of dyspnea in COPD involves both nonpharmacologic and pharmacologic approaches, depending on the causes and the severity of the dyspnea.

There is a need for improved HCP–patient communication, patient education around the management of their dyspnea, and more robust tools for the clinical measurement of dyspnea in COPD.

Introduction

Chronic obstructive pulmonary disease (COPD) is characterized by chronic respiratory symptoms, such as dyspnea, wheezing, chronic cough, and/or acute events of increased respiratory symptoms known as exacerbations [1, 2]. While COPD exacerbations account for the greatest proportion of the total burden of COPD on the healthcare system [3], dyspnea, often progressive over time, is a leading cause of disability and anxiety associated with COPD [4], with chronic dyspnea being the single most common symptom of COPD [1]. Patients may describe the different sensory qualities of their dyspnea, using phrases associated with chest tightness, breathlessness, suffocation, and air hunger, indicating sensations of effort and unsatisfied inspiration [5, 6]. Descriptors of dyspnea are often related to the intensity level of the breathlessness, with highly alarming and emotional responses often cited [7]. Dyspnea presents across all stages of airflow obstruction, often predating the development of recurrent COPD exacerbations [8]. Unlike the variable penetrance of COPD exacerbations, virtually all patients with severe forms of COPD have severe dyspnea symptoms [1, 9]. Patients with COPD with high burden of dyspnea may be overlooked by healthcare providers, as they are likely to adapt their lifestyles around their dyspnea instead of seeking out immediate relief through emergency department or urgent care visits [1, 10].

Initial assessments of dyspnea are an integral component to the diagnosis and management of COPD. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2025 Report recommends standardized assessments such as the modified Medical Research Council (mMRC) Dyspnea Scale to measure breathlessness and the COPD Assessment Test (CAT) to assess health status in patients with COPD [1]. The combined initial GOLD assessment and initial recommended treatment strategies are informed by mMRC and CAT scores [1].

Given that dyspnea is regarded as an important contributor to exacerbations and the overall burden of COPD, attention to dyspnea management is important. Drawing on our collective clinical experience in managing patients with COPD, we discuss current recommendations for the evaluation and management of dyspnea in COPD, identify differences in clinical practice and potential areas of focus to improve outcomes, and provide practical guidance for successful implementation of dyspnea-focused management and intervention of COPD.

Ethics Declaration

Given that this article is based on previously conducted studies and does not report any new research involving human participants or animals performed by any of the authors, there is no ethical compliance to declare.

Mechanisms of Dyspnea in COPD

The most widely accepted consensus of the mechanisms of dyspnea in COPD is that it arises from a neuromechanical dissociation within the respiratory system (Fig. 1a) [2, 11]. This involves a mismatch of efferent neural respiratory drive and afferent feedback during exertion, leading to increased ventilatory drive that is not complemented by adequate pulmonary ventilation [5, 11]. Sensations commonly associated with dyspnea in COPD point to excessive respiratory work and effort required to breathe [5, 11]. These vary in intensity and consistency depending on the patient [5]. While it is clear that dyspneic symptoms altogether produce the overall perception of dyspnea, the underlying pathophysiology of dyspnea in COPD is not fully understood [12].

Fig. 1.

Proposed algorithm for the management of dyspnea in COPD demonstrating a the mechanism of action, causes, and comorbidities of dyspnea in COPD and b the measurement, assessment, and treatments for dyspnea in COPD. Treatment paradigms should be assessed on an individual basis and tailored to meet the needs of each patient depending on dyspnea severity and overall health of the patient. COPD chronic obstructive pulmonary disease, ICS inhaled corticosteroids, LABA long-acting beta-agonists, LAMA long-acting muscarinic antagonists, SABA short-acting beta-agonists, SAMA short-acting muscarinic antagonists

Healthcare Provider (HCP) Assessment of Dyspnea in COPD: Causes of Dyspnea and Patient–HCP Discussion

In the assessment of dyspnea in COPD, it is important to distinguish between dyspnea due to COPD, dyspnea due to pulmonary causes other than COPD (e.g., pulmonary hypertension, bronchiectasis, pulmonary embolism, among others), dyspnea from nonpulmonary causes such as cardiac comorbidities (e.g., congestive heart failure, diastolic dysfunction, or arrythmias), or dyspnea from deconditioning that often coexists with COPD [1, 13]. To achieve this, a key part of HCP assessment of dyspnea in COPD is the use of appropriate physiologic assessments of the underlying causes of dyspnea (Fig. 1b). These include pulmonary function tests, such as spirometry to assess the level of airflow obstruction, body plethysmography to detect hyperinflation and/or air trapping that also contributes to impaired exercise tolerance, and lung diffusion testing (diffusing capacity for carbon monoxide) [1, 14]. Cardiac function in COPD can be measured using tools such as echocardiography to help reveal potential cardiac abnormalities, and aerobic capacity and endurance can be measured using the paced 6-min walk test or the self-paced incremental and endurance shuttle walk tests [1, 15].

When discussing dyspnea with a patient, it must be recognized that dyspnea is often the main complaint reported by patients with COPD [16, 17]. Patients should be queried on the diverse impacts of dyspnea as we find that dyspnea significantly affects patients’ overall quality of life, especially their emotional health and their ability to complete everyday tasks. It has been reported that patients self-limit everyday activities to curtail dyspnea symptoms and that increased dyspnea is correlated with increased anxiety and depression symptoms [18–20]. In addition to its effects on mental health and everyday activities, dyspnea has been shown to have a strong relationship with sleep quality in patients with COPD [21]. When a patient reports sleep-related concerns, it is important to consider both dyspnea-predominant COPD and comorbid conditions that also affect sleep, including obstructive sleep apnea, which can be associated with more frequent cardiovascular morbidity, poorer quality of life, more frequent COPD exacerbations, and increased medical costs [22]. Moreover, weight gain or obesity is a common aggravating factor that can contribute to deterioration in lung function and compound the effects of dyspnea in COPD and should therefore be considered when engaging in patient dialogue [23]. It is also important to recognize that patterns of dyspnea are often not uniform by sex, as evidenced by numerous studies showing that dyspnea is often more pronounced in women [24]. To reduce ascertainment biases, clinician-guided assessments should include quantitative measurements as well as techniques to encourage their patients to discuss their symptoms, resulting in shared decisions with their patients to maximize patients’ quality of life outcomes. This should be achieved through nuanced HCP–patient dialogue that relates to the patient with more open-ended questions, encouraging honest, fruitful discussions about the impact of dyspnea on activities of daily living.

Measurement of Dyspnea Severity

Various measurement scales, such as the mMRC Dyspnea Scale or CAT, are important tools to assess the severity of a patient’s dyspnea (Table 1) [1, 2]. The mMRC Dyspnea Scale and CAT are correlated with other health status measures, such as St. George's Respiratory Questionnaire and the 6-min walk test [1, 25–27]. Other tools such as the Modified Borg Dyspnea Scale, Baseline and Transition Dyspnea Indexes, and Oxygen Cost Diagram measure the functional impact of dyspnea [28–30]. However, there exists a need for more multidimensional, quantitative approaches to measure or predict symptoms and identify reversible factors (e.g., inflammation and associated cough, dyspnea, and exacerbations) and alternative diagnoses [1]. Correlations have been found between dyspnea severity and results from physiologic assessment tests [31, 32]. These can be influenced by both dependent mechanisms related to lung function as well as independent mechanisms, such as ventilatory muscle weakness and elevated systemic inflammation [33]. For instance, dyspnea severity has been shown to have a strong correlation to spirometric restriction and airflow obstruction, and there is a relationship between dyspnea and lung hyperinflation as performed by body plethysmography [31, 32]. Moreover, though biomarkers in COPD have been useful for phenotyping, their role in targeting treatment for dyspnea is less clear [1, 34–39]. The majority of biomarkers for COPD are used primarily in preclinical research settings, while blood eosinophil count (BEC) and natriuretic peptide (B-type natriuretic peptide [BNP] and N-terminal fragment [NT-proBNP]) levels have been utilized in clinical practice in a wide range of disorders beyond COPD [1, 34–41]. Studies have shown correlations of BNP and NT-proBNP with cardiac function in patients with dyspneic COPD, while also demonstrating significant correlations with overall short- and long-term mortality associated with COPD [40, 41]. Though biomarkers have shown clear utility in the relevant differential diagnoses of other diseases, such as procalcitonin for pneumonia, natriuretic peptides for acute heart failure, and D-dimer for pulmonary embolism [37–39], the value of biomarkers in predicting COPD treatment outcomes related to dyspnea is not yet clear and warrants more study.

Table 1.

Patient-completed tools for assessment of dyspnea in COPD

Instrument	Reference publication	Purpose of tool in the context of dyspnea
The modified Medical Research Council (mMRC) Dyspnea Scale	Aaron et al. [77]	Measures the effect of dyspnea on everyday activities
St. George’s Respiratory Questionnaire (SGRQ)	Jones et al. [78, 79]	Items from 3 domains (symptoms, activity, and impact on daily life) are included; dyspnea is included in the symptom scale
Chronic Respiratory Disease Questionnaire (CRQ)	Guyatt et al. [80]	Four domains of 4 to 7 items are evaluated, related to dyspnea, fatigue, emotional function, and mastery
COPD Assessment Test (CAT)	Jones et al. [81]	Includes 8 items related to the severity of dyspnea, sleep quality, self-confidence, etc.
Evaluating Respiratory Symptoms (E-RS)	PPD, Inc [82]	Assesses the effect of treatment on the severity of respiratory symptoms including dyspnea
Borg’s Rating of Perceived Exertion (RPE)	Borg [83]	Gauges effort and exertion, dyspnea, and fatigue during physical work
Baseline and Transition Dyspnea Index (BDI-TDI)	Mahler et al. [84–86]	Measures dyspnea based on functional impairment, magnitude of task, and magnitude of effort, components which evoke dyspnea in activities of daily living
Oxygen Cost Diagram (OCD)	McGavin et al. [87]	Measures dyspnea with activities of daily living using a visual analog scale with descriptions at various points corresponding to oxygen requirements of the related activity
6-min walk test	American Thoracic Society [88]	Assesses walking distance over 6 min as a measure of cardiopulmonary function, with dyspnea often assessed using the RPE scale
Self-paced incremental and endurance shuttle walk tests	Singh et al. [89] and Revill et al. [90]	Assesses time to walk up and down a 10-m course, either at increasing speeds (incremental) or at constant speed (endurance), with dyspnea often assessed using the RPE scale

COPD chronic obstructive pulmonary disease

Management of Dyspnea in COPD

Aside from self-management and nonpharmacologic strategies for dyspnea, dual bronchodilator therapy is among the first lines of therapy for dyspneic COPD, consisting of long-acting beta-agonists (LABA)/long-acting muscarinic antagonists (LAMA) [1, 2]. The use of inhaled corticosteroid (ICS) triple therapy is reserved for patients not responding to LABA/LAMA therapy and is most appropriate for patients with elevated BECs (≥ 300 cells/µL), comorbid asthma, and prior exacerbations [1]. While we follow GOLD recommendations in our own practices, primary care providers (PCPs) may be less aware of all up-to-date recommendations, particularly given the multitude of comorbidities they are managing. Moreover, as mentioned previously, dyspnea may not be solely due to a patient’s COPD or may be due to nonpulmonary causes, given that the prevalence of comorbidities is high in this patient population [1]. In these instances, PCPs may be less likely to consult COPD-specific documents like GOLD [42]. As PCPs often screen for numerous conditions, the assessment of dyspnea alone may be challenging. Therefore, a more streamlined approach for dissemination of practical recommendations is needed for ease of implementation, regardless of the care setting.

Pharmacologic Management of Dyspnea in COPD

Current GOLD recommendations suggest the use of dual bronchodilator therapy in patients with dyspneic COPD and those who experience frequent exacerbations, and, in line with our experience, many respiratory clinicians choose to initiate dual bronchodilator therapy rather than monotherapy in treatment-naïve patients [1]. For patients already on dual bronchodilator therapy, providers generally agree that dyspnea improves with the addition or escalation of nonpharmacologic treatments, such as pulmonary rehabilitation, structured exercise with supplemental ambulatory oxygen if desaturation or hypoxia is experienced during exertion (although shortness of breath may not always point to lack of oxygen), or surgical interventions (as discussed below) [1, 43]. The addition of other pharmacologic interventions may be warranted when available, such as the dual phosphodiesterase (PDE)3 and PDE4 inhibitor ensifentrine, which was recently approved by the US Food and Drug Administration for the maintenance treatment of COPD [44]. These interventions should be given in conjunction with evaluating inhaler technique and the appropriateness of the drug delivery device being used [1]. Most often, patients referred to respiratory clinicians who are already on triple therapy with ICS continue to experience persistent dyspnea. Given that respiratory providers often prescribe dual bronchodilator therapy rather than bronchodilator monotherapy from the start, the addition of nonpharmacologic treatments or ensifentrine may be warranted if dyspnea is not well controlled on dual therapy. Triple therapy is generally prescribed only in the setting of elevated BECs, in patients who experience severe exacerbations associated with hospitalization and in patients with certain comorbidities (i.e., asthma); its de-escalation is otherwise encouraged in patients not meeting these criteria [1, 45]. Related to this, ensifentrine is recommended per the 2025 GOLD Report in patients with dyspnea who remain symptomatic despite dual bronchodilator therapy, given the clinically significant improvements in lung function and measures of dyspnea in the phase 3 ENHANCE trials [1, 46]. Although patients on triple therapy with ICS were not studied in these trials, it is reasonable to recommend ensifentrine, as per the 2025 GOLD Report, on the basis of its improvement of patient-reported outcomes, including assessments of dyspnea [1, 46, 47]. While maintenance nebulizer therapy consisting of short-acting beta-agonists (SABA)/short-acting muscarinic antagonists (SAMA) may be used on an as-needed basis, they are recommended as supplementation to longer-acting agents, given that their therapeutic effects typically last only 4–6 h [1, 48, 49]. In addition, while there is insufficient evidence to support the use of opioids or benzodiazepines as a treatment in managing dyspnea, given the risks of respiratory depression and mortality associated with their use, they have utility as adjunct therapy for severe anxiety in patients with dyspneic COPD, particularly in cases of what is known as the dyspnea panic cycle, or in end-of-life palliative care [50–52].

Use of Inhaler Devices for Dyspnea in COPD

For patients on bronchodilator therapy using inhalers, there may exist a gap in patient education, as incorrect inhaler technique is commonly encountered in patients with COPD [53, 54]. Clinicians should make all efforts to educate their patients on proper inhaler technique. If an incorrect technique is identified, careful step-by-step education should be provided, and some patients may require more time than others during these educational sessions. Involving respiratory therapists and other ancillary personnel can also provide additional value in this setting, particularly for those patients that require frequent education to emphasize proper use of their inhalers [55]. Only if all other options have been exhausted, changing the delivery device may be considered, which may be comparable in benefit to switching the drug molecule class [56]. An alternative approach is to provide nursing or respiratory therapy support to teach patients and observe proper technique, which has been supported by the literature [57]. In addition, there oftentimes exist logistical challenges with medication adherence after switching inhalers due to formulary changes related to cost, generic substitution, and drug availability [58]. Therefore, onsite pharmacy support for clinics would help to mitigate these challenges. As practices differ in time and resources available for instructing patients on proper inhaler technique, there is room for improved education resources in this area.

Nonpharmacologic Management of Dyspnea in COPD

If a patient with COPD is among the 40% who continue to smoke tobacco products, a key intervention tactic in the nonpharmacologic management of dyspnea in COPD is the cessation of smoking [1]. Moreover, although e-cigarette vaping has been perceived as a possible low-risk replacement for smoking, the long-term health effects in patients with dyspneic COPD are largely unknown, with emerging data linking it with incident COPD [1, 59, 60]. Reducing exposure to household and environmental pollutants is another route advised by current GOLD recommendations [1]. Another important part of nonpharmacologic management of dyspnea in COPD involves the introduction of exercise and pulmonary rehabilitation regimens for sustained improvement in lung and cardiac function [1]. Weight gain and obesity are correlated with the intensity of dyspnea, and a regimented exercise program can help mitigate these effects [1, 61]. Because patients with dyspneic COPD also often suffer from comorbid depression and anxiety, these rehabilitation programs also aim to improve the quality of life of patients with COPD [1]. Moreover, there is evidence that psychotherapy approaches such as short-term cognitive behavioral therapy sessions can be effective for anxiety and depression in patients with COPD when delivered by respiratory healthcare personnel [62]. The self-management approach, with targeted strategies for handling breathlessness, conservation techniques, and stress management, is also a key component of dyspnea control [1]. These strategies may include leaning forward to decrease inspiratory muscle burden; pacing; using fans and/or cool airflow; and nutritional interventions, for weight loss in patients who are overweight or obese or for increased respiratory muscle strength in cases of COPD-associated weight loss due to elevated metabolic activity that is sometimes observed with the disease [5, 63–65]. Other self-management methods, such as relaxation, may vary in success [66, 67]. Methods such as pursed-lip breathing and noninvasive ventilation have also been shown to provide relief of dyspnea [68, 69]. Mobility aids such as scooters or stairlifts, in-home pulmonary care programs, and long-term or rescue oxygen therapy for patients with resting hypoxia can also help reduce the physical burden for patients with dyspneic COPD [1, 70, 71]. While surgical interventions are sometimes an option, this method of management is useful in select patient populations and phenotypes of COPD [72]. For instance, patients with upper lobe predominant emphysema, which consists of hyperinflation with ventilation–perfusion mismatch, are oftentimes good candidates for bronchoscopic lung volume reduction surgery [73, 74]. In these cases, referral to a specialist is crucial for proper evaluation of surgical and interventional options. The emerging technique of targeted lung denervation, which modifies biofeedback mechanisms driving dyspnea, has been shown to improve pulmonary function and quality of life 3 years post-treatment and is therefore warranted for patients with persistent dyspnea [75]. Strategies to cope with breathlessness, rather than seeking a curative measure for dyspnea, become especially crucial in advanced stages of dyspneic COPD as part of end-of-life palliative care [76]. These include oxygen therapy for symptom control; administration of opioids, benzodiazepines, or other anxiolytic drugs to quell symptoms of anxiety; and physical and emotional nonpharmacologic methods that aim to create a comfortable environment for the patient [76]. Thus, while some simple nonpharmacologic management options exist, these are limited. More rigorous assessment of activity levels, deconditioning, cardiac dysfunction, and pulmonary dysfunction in dyspnea is warranted to determine the proper course of action for nonpharmacologic management of dyspnea in COPD.

Overall Assessment of Dyspnea Management and Recommendations for Improvement

Overall, many patients with COPD still experience significant dyspnea despite being on maintenance therapy. We recommend that HCPs treating COPD take a dynamic approach to the management of dyspnea in COPD, and this should be reflected in a more robust roadmap for using recommendations, particularly in the primary care setting. In addition to nonpharmacologic and pharmacologic treatments for dyspnea in COPD, these paradigms should be followed by management and rehabilitation pathways tailored to the individual patient (Fig. 1).

Conclusions and Calls to Action

In this clinical commentary, we offer practical insight for dyspnea assessment and management in clinical practice (Table 2). Clinician-guided recommendations for dyspnea management in COPD include improved dissemination of recommendations for HCPs, especially among PCPs, in an effort to standardize the assessment of dyspnea in COPD. This may include more validated patient-reported outcome measures that would more accurately quantify COPD-related dyspnea [18]. Clinicians must also consider both pulmonary and nonpulmonary causes of dyspnea and initiate both pharmacologic and nonpharmacologic treatments as part of a comprehensive treatment plan. Moreover, improved patient education involves implementing resources, including advice and counseling resources for smoking or vaping cessation and recognition of environmental exposures, face-to-face inhaler technique instructions, and information on nonpharmacologic treatment options for dyspnea in COPD. Further investigation into novel methods for improving dyspnea in COPD is needed. Ultimately, optimal recognition and management of dyspnea in COPD will improve the quality of life of patients suffering from COPD.

Table 2.

Clinical pearls for dyspnea assessment and management of dyspnea in COPD

Topic	Insights
Patient–HCP assessment of dyspnea in COPD	Quantitative measurements such as spirometry and echocardiography should be coupled with open dialogue between patients and HCPs
Measurement of dyspnea severity	While patient-completed scales such as the mMRC Dyspnea Scale and CAT are often used, a multifaceted measurement approach should include detailed history, patient-completed dyspnea scales, and objective measurements to generate a robust differential diagnosis
Overall management of dyspnea in COPD	Effective and efficient dissemination of treatment strategy recommendations to HCPs is essential
Pharmacologic management of dyspnea in COPD	Dual bronchodilator therapy is the most preferred option, with the addition of ensifentrine if dyspnea persists
Use of inhaler devices for dyspnea in COPD	Given that institutions vary in the resources available for proper use and technique of inhaler devices, onsite pharmacy support would help alleviate patient education gaps
Nonpharmacologic management of dyspnea in COPD	All patients with dyspnea impacting their quality of life should be referred for pulmonary rehabilitation, counseled on smoking cessation, and treated for comorbid depression and anxiety when present
Overall assessment of dyspnea in COPD and recommendations for improvement	Treatment paradigms for dyspnea in COPD should be followed by individualized management and rehabilitation schemes, particularly in the primary care setting

CAT COPD assessment test, COPD chronic obstructive pulmonary disease, HCP healthcare provider, mMRC modified Medical Research Council

Author Contributions

Nirupama Putcha, Diego J. Maselli, Jessica Bon, Michael G. Lester, and M. Bradley Drummond were involved in the manuscript’s conception and execution; participated in the interpretation of the data; critically reviewed and revised manuscript drafts; agreed on the journal to which the manuscript was submitted; and provided approval of manuscript versions throughout the development process. All authors agree to be accountable for the contents of the article.

Funding

The study and the journal’s Rapid Service Fee were funded by Verona Pharma (Raleigh, North Carolina).

Data Availability

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

Declarations

Conflict of Interest

Nirupama Putcha has served on advisory boards for Verona Pharma and AstraZeneca. Diego J. Maselli has served on consulting/advisory boards for GSK, AstraZeneca, Amgen, Sanofi/Regeneron, Insmed, and Verona Pharma; and has received speaker fees from GSK, AstraZeneca, Amgen, and Sanofi/Regeneron. Jessica Bon has received grant funding from the National Heart, Lung, and Blood Institute (NHLBI); has served on consulting/advisory boards for GSK, Sanofi/Regeneron, Verona Pharma, and Chiesi; and has received speaker fees from GSK and Sanofi/Regeneron. Michael G. Lester has served on consulting/advisory boards for Ryme Medical, Galvanize Therapeutics, and Verona Pharma. M. Bradley Drummond has served on consulting/advisory boards for GlaxoSmithKline, Boehringer Ingelheim, AstraZeneca, Verona, Genentech, Stratos Inc, Takeda, and Amgen and has received grant funding from National Institute of Health-NHLBI, Boehringer Ingelheim, Midmark, Teva and the American Lung Association.

Ethical Approval

Given that this article is based on previously conducted studies and does not report any new research involving human participants or animals performed by any of the authors, there is no ethical compliance to declare.