Classification of Cough as a Symptom in Adults and Management Algorithms: CHEST Guideline and Expert Panel Report

Efficacy, Safety and Economic Evaluation of Wolbigachul-Tang for Chronic Cough Due to Upper Airway Cough Syndrome (UACS): A Study Protocol for Randomized, Double-Blind, Active-Comparator Controlled, Parallel, Exploratory Clinical Trial

Upper airway cough syndrome (UACS) is a common cause of chronic cough characterized by upper airway symptoms, including nasal discharge and throat discomfort. Empirical treatments for UASC-induced chronic cough, such as first-generation antihistamines, have been used; however, the long-term use of these medicines has adverse effects. Therefore, we evaluate the efficacy, safety, and economic feasibility of Wolbigachul-tang (WBGCT), an herbal medication for UASC-induced chronic cough. This is a randomized, double-blind, active-comparator-controlled, parallel, and exploratory clinical trial. Thirty patients with UASC-induced chronic cough will be recruited and randomly allocated to the WBGCT and control groups in a 1:1 allocation ratio. The investigational medicine will be administered three times per day for 2 weeks (3 g of WBGCT at a time). The primary outcome measure is the cough symptom score measured at screening, before starting the trial, and after 2 and 4 weeks. Secondary outcome measures include the cough visual analog scale, nasal discharge score, questionnaire of clinical symptoms of cough and sputum, Leicester cough questionnaire-Korean version, integrative medicine outcome scale, integrative medicine patient satisfaction scale, and 5-level EuroQol 5-dimensional questionnaire, which will be assessed before starting the trial and after 2 and 4 weeks. This study aims to investigate the efficacy, safety, and economic feasibility of WBGCT in the treatment of chronic cough. Therefore, the results of this trial provide evidence for the application of WBGCT in the treatment of UACS-induced chronic cough.

Comparative Efficacy of Anti-asthma Therapy in Non-asthmatic Cough: A Cross-Sectional Study in Dubai, United Arab Emirates

Background Cough is one of the most common presenting complaints for physicians across the world, with the potential to result in a significant influence on one's daily life. It is typically categorized into acute cough (<3 weeks), subacute cough (three to eight weeks), and chronic cough (>8 weeks). The lack of specific treatment guidelines and evidence-based recommendations for resolving cough creates reasonable controversy in the medical field. This retrospective study aims to identify the clinical features of cough and evaluate the comparative efficacy between different anti-asthmatic treatment modalities in the urban city of Dubai, United Arab Emirates. Methods A retrospective cross-sectional study was performed on patients presenting to pulmonology or respiratory outpatient clinics with complaints of cough in the absence of any known history of chronic respiratory illness (e.g., asthma). Analysis was conducted via chi-squared and analysis of variance (ANOVA) testing. Results A total of 308 patients were eligible for inclusion, with 273 patients presenting for follow-up. Overall, patients with acute, subacute, and chronic coughs had similar clinical presentations, with no statistically significant differences noted. However, patients with pets were more likely to develop an acute cough (p = 0.04). Moreover, the follow-up outcomes of acute, subacute, and chronic cough were similar, with no significant statistical difference noted. Furthermore, patients receiving dual therapy using budesonide and montelukast, and patients receiving triple therapy using budesonide, montelukast, and tiotropium/ipratropium were most likely to gain complete relief of their symptoms, although triple therapy treatment was also associated with the highest rate of null improvement (p = 0.012). Additionally, chronic cough patients were more likely to be subject to higher C-reactive protein (CRP) levels in comparison to other cohorts (p = 0.26). Conclusion The comparative superiority of dual therapy using budesonide and montelukast, and triple therapy using budesonide, montelukast, and tiotropium/ipratropium were highlighted in this study. In the sparseness of specific treatment guidelines and evidence-based recommendations for cough, the use of anti-asthmatic therapy for cough patients has shown favorable results. Moreover, the lack of clinical differences between acute, subacute, and chronic cough may result in difficulties with the treatment of cough patients. To arrive at a valid conclusion, further comprehensive studies with larger and more diversified sample populations are encouraged.

Baseline Cohort Profile of the Korean Chronic Cough Registry: A Multicenter, Prospective, Observational Study

PURPOSE

The Korean Chronic Cough Registry study was initiated to characterize patients with chronic cough (CC) and investigate their outcomes in real-world clinical practice. This report aims to describe the baseline cohort profile and study protocols.

METHODS

This multicenter, prospective observational cohort study included newly referred CC patients and those already being treated for refractory or unexplained chronic cough (RUCC). Cough status was assessed using a visual analog scale, the Leicester Cough Questionnaire (LCQ), and the Cough Hypersensitivity Questionnaire (CHQ).

RESULTS

A total of 610 patients (66.9% women; median age 59.0 years) were recruited from 18 centers, with 176 being RUCC patients (28.9%). The median age at CC onset was 50.1 years, and 94.4% had adult-onset CC (≥ 19 years). The median cough duration was 4 years. Compared to newly referred CC patients, RUCC patients had a longer cough duration (6.0 years vs. 3.0 years) but had fewer symptoms and signs suggesting asthma, rhinosinusitis, or gastroesophageal acid reflux disease. Subjects with RUCC had lower LCQ scores (10.3 ± 3.3 vs. 11.6 ± 3.6; P < 0.001) and higher CHQ scores (9.1 ± 3.9 vs. 8.4 ± 4.1; P = 0.024). There were no marked differences in the characteristics of cough between refractory chronic cough and unexplained chronic cough.

CONCLUSIONS

Chronic cough typically develops in adulthood, lasting for years. Cough severity and quality of life impairment indicate the presence of unmet clinical needs and insufficient cough control in real-world clinical practice. Longitudinal follow-up is warranted to investigate the natural history and treatment outcomes.

Patterns of Cough Medication Prescribing among Patients with Chronic Cough in Florida: 2012-2021

Among patients with chronic cough (CC) in the 2012-2021 statewide OneFlorida Clinical Research Consortium database, we examined trends in cough medication (CM) prescribing prevalence over time in repeated cross-sectional analyses and identified distinct CM utilization trajectories using group-based trajectory modeling (GBTM) in a retrospective cohort study. Among eligible adults (≥18 years) without cancer/benign respiratory tumor diagnoses, we identified CC patients and non-CC patients with any cough-related diagnosis. In the GBTM analysis, we calculated the number of monthly prescriptions for any CMs (excluding gabapentinoids) during the 12 months from the first qualifying cough event to identify distinct utilization trajectories. From 2012 to 2021, benzonatate (9.6% to 26.1%), dextromethorphan (5.2% to 8.6%), and gabapentinoid (5.3% to 14.4%) use increased among CC patients, while opioid antitussive use increased from 2012 to 2015 and decreased thereafter (8.4% in 2012, 14.7% in 2015, 6.7% in 2021; all p < 0.001). Of 15,566 CC patients and 655,250 non-CC patients identified in the GBTM analysis, CC patients had substantial burdens of respiratory/non-respiratory comorbidities and healthcare service and concomitant medication use compared to non-CC patients. Among CC patients, GBTM identified three distinct CM utilization trajectories: (1) no CM use (n = 11,222; 72.1%); (2) declining CM use (n = 4105; 26.4%); and (3) chronic CM use (n = 239; 1.5%). CC patients in Florida had limited CM use with increasing trends in use of benzonatate, dextromethorphan, and gabapentinoids and a decreasing trend in opioid antitussive use. CC patients, particularly with chronic prescription CM use, experienced substantial disease burden.

Disease burden, comorbidities and antecedents of chronic cough phenotypes in Australian adults

BACKGROUND AND OBJECTIVES

While adult chronic cough has high burden, its phenotypes, particularly those without aetiologically related underlying conditions, are understudied. We investigated the prevalence, lung function and comorbidities of adult chronic cough phenotypes.

METHODS

Data from 3608 participants aged 53 years from the Tasmanian Longitudinal Health Study (TAHS) were included. Chronic cough was defined as cough on most days for >3 months in a year. Chronic cough was classified into "explained cough" if there were any one of four major cough-associated conditions (asthma, COPD, gastroesophageal reflux disease or rhinosinusitis) or "unexplained cough" if none were present. Adjusted regression analyses investigated associations between these chronic cough phenotypes, lung function and non-respiratory comorbidities at 53 years.

RESULTS

The prevalence of chronic cough was 10% (95%CI 9.1,11.0%) with 46.4% being "unexplained". Participants with unexplained chronic cough had lower FEV1/FVC (coefficient: -1.2% [95%CI:-2,3, -0.1]) and increased odds of comorbidities including obesity (OR=1.6 [95%CI: 1.2, 2.3]), depression (OR=1.4 [95%CI: 1.0, 2.1]), hypertension (OR=1.7 [95%CI: 1.2, 2.4]) and angina, heart attack or myocardial infarction to a lesser extent, compared to those without chronic cough. Participants with explained chronic cough also had lower lung function than both those with unexplained chronic cough and those without chronic cough.

CONCLUSIONS

Chronic cough is prevalent in middle-age and a high proportion is unexplained. Unexplained cough contributes to poor lung function and increased comorbidities. Given unexplained chronic cough is not a symptom of major underlying respiratory conditions it should be targeted for better understanding in both clinical settings and research.

Bacterial Etiology in Subacute Cough

Although postinfectious etiology is the most common cause of subacute cough, there are insufficient data on the epidemiology of associated bacterial infections. We aimed to identify the etiology of bacterial detection in subjects with subacute cough. A multicenter prospective observational study of 142 patients with postinfectious subacute cough was performed between August 2016 and December 2017 in Korea. We obtained 2 nasal swabs from each patient and used a multiplex bacterial polymerase chain reaction (PCR) kit that simultaneously detects Bordetella pertussis, Chlamydophila pneumoniae, Haemophilus influenzae, Legionella pneumophilia, Mycoplasma pneumoniae, and Streptococcus pneumoniae. About 29% (n = 41) of patients with subacute cough were positive for bacterial PCR in nasal swabs. The most common bacteria detected by bacterial PCR was H. influenzae (n = 19, 13.4%), followed by S. pneumoniae (n = 18, 12.7%), B. pertussis (n = 7, 4.9%), M. pneumoniae (n = 3, 2.1%), L. pneumophilia (n = 2, 1.4%), and C. pneumoniae (n = 1, 0.7%). Nine patients had dual positivity for the PCR. In conclusion, bacterial PCR was positive in the nasal swabs of about 29% of subjects with subacute cough, including 5% of positive PCR results for B. pertussis.

Effects of bepotastine, a nonsedating H1-antihistamine, for the treatment of persistent cough and allergic rhinitis: a randomised, double-blind, placebo-controlled trial

Background

Empirical therapy with oral histamine-1 receptor antagonists (H1RAs) is often used for patients with suspected upper airway cough syndrome. No placebo-controlled trials with nonsedating H1RAs (nsH1RAs) have evaluated validated cough outcomes. The objective of the present study was to assess the effect of an nsH1RA, bepotastine, on cough outcomes in patients with allergic rhinitis and persistent cough.

Methods

A randomised, double-blind, placebo-controlled trial was conducted. Adult patients with persistent cough (>3 weeks in duration) and symptomatic allergic rhinitis were recruited and randomly assigned to receive either bepotastine or placebo at a 1:1 ratio. The primary outcome was cough-specific quality of life assessed using the Leicester Cough Questionnaire (LCQ). Secondary outcomes included cough severity visual analogue scale (VAS), throat VAS, Cough Hypersensitivity Questionnaire, Sinonasal Outcome Test-22 score and drug adverse events.

Results

Between October 2021 and September 2022, 50 participants (43 females; mean age 46.28 years; median cough duration 3 months) were assigned to either the bepotastine 10 mg twice daily or placebo group in a 1:1 ratio. After 2 weeks of treatment, both bepotastine and placebo groups showed significant improvements in the LCQ scores, but there was no significant difference in the magnitude of change between the groups (3.45±2.10 versus 3.04±2.94, p=0.576). Secondary outcomes were also comparable.

Conclusions

Despite the relatively small sample size, our study clearly demonstrated that a 2-week treatment with bepotastine did not provide therapeutic benefits for cough outcomes. These findings suggest against the use of nsH1RAs with the intention of improving cough outcomes, even in patients with persistent cough and allergic rhinitis.

Unravelling vagal hypersensitivity in chronic cough: A distinct disease

Chronic cough (CC) is a common but poorly understood disease that has a negative impact on quality of life. For years, clinicians have been trying to find the underlying diagnosis and using existing disease models to describe the patients' illness. This presents a confusing picture of CC. Most patients with CC present with hypersensitivity of the cough reflex, which is characterised by laryngeal paraesthesia and an increased response to the tussive stimuli or an innocuous stimulus that would not trigger coughing in healthy people. Recently, it has been proposed that CC is a unique disease characterised by vagal hypersensitivity that projects to the central nervous system altering responsiveness. The evidence supports the hypothesis that CC is primarily a neurological disorder, consisting of different phenotypes.

Association of lower plasma citric acid with prolonged cough: the Nagahama study

Little is known about the association of prolonged cough, a common and troublesome symptom, with metabolic pathways. We aimed to clarify this association using data from the Nagahama cohort, a prospective study of participants from the general population. Self-report questionnaires on prolonged cough were collected at baseline and 5-year follow-up assessments. Blood tests at follow-up were used for gas chromatography-mass spectrometry-based metabolomics. The association between metabolites and prolonged cough was examined using the partial least squares discriminant analysis and multiple regression analysis. Among the 7432 participants, 632 had newly developed prolonged cough at follow-up, which was defined as "new-onset prolonged cough". Low plasma citric acid was significantly associated with new-onset prolonged cough, even after the adjustment of confounding factors including the presence of asthma, upper airway cough syndrome (UACS), and gastroesophageal reflux disease (GERD). A similar association was observed for isocitric acid, 3-hydroxybutyric acid, and 3-hydroxyisobutyric acid. The analysis of these four metabolites revealed that citric acid had the strongest association with new-onset prolonged cough. This significant association remained even when the analysis was confined to participants with UACS or GERD at baseline or follow-up, and these associations were also observed in participants (n = 976) who had prolonged cough at follow-up regardless of baseline status. In conclusion, low blood citric acid may be associated with prolonged cough.

From bench to bedside: The role of cough hypersensitivity in chronic cough

BACKGROUND

Chronic cough is a burdensome condition characterized by persistent cough lasting longer than 8 weeks. Chronic cough can significantly affect quality of life, physical function and productivity, with many people troubled with a cough that lasts for months or even years. People with chronic cough commonly report a persistent urge to cough with frequent bouts of coughing triggered by innocuous stimuli, which has led to the concept of cough hypersensitivity.

MAIN BODY

Both central and peripheral neural pathways regulate cough, and although mechanisms driving development of cough hypersensitivity are not fully known, sensitization of these neural pathways contributes to excessive cough triggering in cough hypersensitivity. Effective therapies that control chronic cough are currently lacking. Recent therapeutic development has focused on several ion channels and receptors involved in peripheral activation of cough (e.g., transient receptor potential channels, P2 × 3 receptors and voltage-gated sodium channels) or central cough processing (e.g., neurokinin-1 [NK-1] receptors and nicotinic acetylcholine receptors).

CONCLUSION

These targeted therapies provide novel insights into mechanisms underlying cough hypersensitivity and may offer new treatment options for people with chronic cough. In this review, we explore preclinical and clinical studies that have improved our understanding of the mechanisms responsible for chronic cough and discuss the most promising targeted approaches to date, including trials of P2 × 3-receptor antagonists and NK-1-receptor antagonists.

Population pharmacokinetic analysis of the P2X3-receptor antagonist gefapixant

Gefapixant, a P2X3-receptor antagonist, demonstrated objective and subjective efficacy in individuals with refractory or unexplained chronic cough. We report a population pharmacokinetic (PopPK) analysis that characterizes gefapixant pharmacokinetics (PKs), quantifies between- and within-participant variability, and evaluates the impact of intrinsic and extrinsic factors on gefapixant exposure. The PopPK model was initially developed using PK data from six phase I studies. Stepwise covariate method was utilized to identify covariates impacting PK parameters; the model was re-estimated and covariate effects were re-assessed after integrating PK data from three phase II and III studies. Simulations were conducted to evaluate the magnitude of covariate effects on gefapixant exposure. Of 1677 participants included in this data set, 1618 had evaluable PK records. Age, body weight, and sex had statistically significant, but not clinically relevant, effects on exposure. Degree of renal impairment (RI) had statistically significant and clinically relevant effects on exposure; exposure was 17% to 89% higher in those with versus without RI. Simulation results indicated that gefapixant 45 mg administered once daily to patients with severe RI has similar exposure to gefapixant 45 mg administered twice daily to patients with normal renal function. There were no significant effects of proton pump inhibitors or food. Of evaluated intrinsic and extrinsic factors, only RI had a clinically relevant effect on gefapixant exposure. Patients with mild or moderate RI do not require dosage adjustments; however, for patients with severe RI who are not on dialysis, gefapixant 45 mg once daily is recommended.

Cough Hypersensitivity Syndrome: Why Its Use Is Inappropriate in Children

In children and adults, chronic cough is a common symptom presenting to health professionals worldwide. It is internationally accepted that children with chronic cough should be managed with pediatric specific management guidelines. The newly proposed clinical entity of 'cough hypersensitivity syndrome' has gained significant attention in adult literature. Given the significant differences between childhood and adult chronic cough, including in respiratory physiology and anatomy, and cough sensitivity, we address the suitability of the use of cough hypersensitivity syndrome in children. We explore these differences between childhood and adult chronic cough, explain what cough hypersensitivity is and highlight why the term cough hypersensitivity syndrome should not be used in children.

Efficacy and safety of gefapixant for chronic cough: a meta-analysis of randomised controlled trials

BACKGROUND

The efficacy and safety of gefapixant in adults with chronic cough remain unclear. Our objective was to assess the efficacy and safety of gefapixant using updated evidence.

METHODS

MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and Embase databases were searched from inception through September 2022. Subgroup analysis based on dose of gefapixant (i.e. ≤20, 45-50 and ≥100 mg twice daily for low, moderate and high doses, respectively) was performed to explore a potential dose-dependent effect.

RESULTS

Five studies involving seven trials showed the efficacy of moderate- or high-dose gefapixant for reducing objective 24-h cough frequency (estimated relative reduction 30.9% and 58.5%, respectively) (i.e. primary outcome) and awake cough frequency (estimated relative reduction 47.3% and 62.8%, respectively). Night-time cough frequency was only reduced with high-dose gefapixant. Consistently, the use of moderate- or high-dose gefapixant significantly alleviated cough severity and improved cough-related quality of life, but increased the risk of all-cause adverse events (AEs), treatment-related AEs and ageusia/dysgeusia/hypogeusia. Subgroup analysis showed dose dependency in both efficacy and AEs with a cut-off dose being ≥45 mg twice daily.

CONCLUSIONS

This meta-analysis revealed dose-dependent efficacy and adverse effects of gefapixant against chronic cough. Further studies are required to investigate the feasibility of moderate-dose (i.e. 45-50 mg twice daily) gefapixant in clinical practice.

Cross-country skiers often experience respiratory symptoms during and after exercise but have a low prevalence of prolonged cough

Background

Cross-country skiers train and compete during the winter for long periods of time in subfreezing conditions, which strains the airways and provokes respiratory symptoms. This study aimed to compare the prevalence of exercise-related symptoms and prolonged cough in competitive cross-country skiers versus the general population and to investigate the association between these symptoms and asthma.

Methods

A questionnaire was sent to Finnish cross-country skiers (n=1282) and a random sample of the general population (n=1754), with response rates of 26.9% and 19.0%, respectively.

Results

Both groups were mostly asymptomatic at rest, but symptoms were increased in both groups during and after exercise. Cough was more prevalent after exercise in skiers and phlegm production was more common during and after exercise in skiers. Asthma did not provoke specific symptoms, but symptom prevalence was higher in asthmatic individuals. Skiers had a higher prevalence of cough after exercise (60.6% vs 22.8%, p<0.001) compared with controls, but controls had a higher prevalence of prolonged cough (4.1% vs 9.6%, p=0.004). In participants without asthma, cold air triggered symptoms more often in skiers than controls, while strong odours triggered symptoms more often in asthmatic controls than skiers. Chronic cough lasting more than 8 weeks was rare, reported by 4.8% of controls and 2.0% of skiers.

Conclusion

Cross-country skiers, especially those with asthma, experience a higher burden of exercise-related respiratory symptoms compared with controls. However, repeated exposure to cold air does not appear to result in long-term hypersensitivity of the cough reflex arc.

Guidelines for the management of chronic cough in adults. Endorsed by the French speaking society of respiratory diseases (Société de Pneumologie de Langue Française, SPLF), the Société Française d'Oto-Rhino-Laryngologie et de Chirurgie de la Face et du Cou (SFORL), the Société Française de Phoniatrie et de Laryngologie (SFPL), the Société Nationale Française de Gastro-entérologie (SNFGE)

Patients with chronic cough experience a high alteration of quality of life. Moreover, chronic cough is a complex entity with numerous etiologies and treatments. In order to help clinicians involved in the management of patients with chronic cough, guidelines on chronic cough have been established by a group of French experts. These guidelines address the definitions of chronic cough and the initial management of patients with chronic cough. We present herein second-line tests that might be considered in patients with cough persistence despite initial management. Experts also propose a definition of unexplained or refractory chronic cough (URCC) in order to better identify patients whose cough persists despite optimal management. Finally, these guidelines address the pharmacological and non-pharmacological interventions useful in URCC. Thus, amitryptilline, pregabalin, gabapentin or morphine combined with speech and/or physical therapy are a mainstay of treatment strategies in URCC. Other treatment options, such as P2 × 3 antagonists, are being developed.

Characteristics of idiopathic pulmonary fibrosis -associated cough. a case-control study

BACKGROUND

Most patients with idiopathic pulmonary fibrosis (IPF) complain of cough. IPF-associated cough is widely characterized as dry or non-productive. The aim of this study was to compare chronic cough in early stage IPF patients to cough in subjects with chronic cough from a community-based sample and, especially, to investigate whether cough in IPF is less productive than chronic cough in a community-based sample.

METHODS

The IPF cough population consisted of 46 biopsy-confirmed patients who complained of chronic cough. Control population consisted of subjects with chronic cough, gathered by a community-based email survey sent to public service employees and the Finnish Pensioners' Federation. A case-control setting was applied by having four age, gender, and smoking-status matched subjects from the community sample for each IPF cough patient. A cough specific quality of life questionnaire (Leicester Cough Questionnaire (LCQ)) was filled in by all subjects. The LCQ questionnaire contains 19 questions, each question is scored from 1 to 7 and total score from 3 to 21 with a smaller value indicating more severe impairment.

RESULTS

The sputum production frequency, as assessed by LCQ question 2, was 5.0 (3.0-6.0) in the IPF chronic cough population and 5.0 (3.0-6.0) in the community-based chronic cough population (median and interquartile range p= 0.72). The LCQ total score was 14.8 (11.5-18.1) in the IPF chronic cough population and 15.4 (13.0-17.5) in the community-based chronic cough population (p=0.76). The domain impact scores were physical, 4.9 (3.9-6.1) vs. 5.1 (4.5-5.6) (p=0.80); psychological, 4.6 (3.7-5.9) vs. 4.7 (3.9-5.7) (p=0.90); and social, 5.5 (3.7-6.5) vs. 5.5 (4.5-6.3) (p=0.84), respectively. Furthermore, cough response to paint or fumes, cough disturbing sleep, and cough frequency per day did not differ between the groups.

CONCLUSION

Cough in early stage IPF patients was not distinguishable from chronic cough in the community-based population by LCQ. Especially, there was no difference in the self-reported frequency of cough-associated sputum production.

[Guidelines for the management of chronic cough in adults]

Patients with chronic cough experience major alteration in their quality of life. Given its numerous etiologies and treatments, this disease is a complex entity. To help clinicians involved in patient management of patients, guidelines have been issued by a group of French experts. They address definitions of chronic cough and initial management of patients with this pathology. We present herein the second-line tests that might be considered in patients whose coughing has persisted, notwithstanding initial management. The experts have also put forward a definition of unexplained or refractory chronic cough (URCC), the objective being to more precisely identify those patients whose cough persists despite optimal management. Lastly, these guidelines indicate the pharmacological and non-pharmacological interventions of use in URCC. Amitriptyline, pregabalin, gabapentin or morphine combined with speech and/or physical therapy are mainstays in treatment strategies. Other treatment options, such as P2X3 antagonists, are being developed and have generated high hopes among physicians and patients alike.

Health-Related Quality of Life and Its Determinants in Chronic Cough: The Korean Chronic Cough Registry Study

PURPOSE

Chronic cough (CC) is associated with health-related quality of life (HRQoL) impairment. However, the determinants of HRQoL are under-investigated.

METHODS

Patients aged 19-80 years with CC were prospectively recruited from 10 referral clinics. Comparisons were made with age- and sex-matched controls (1:4 ratio) selected from a Korean general population survey database; 1) a group without current cough (non-cough controls) and 2) another group without major chronic illnesses (healthy controls). HRQoL was assessed using the EuroQoL 5-dimension (EQ-5D) index. In CC patients, cough-specific patient-reported outcomes (PROs) were additionally measured. Cross-sectional analyses were performed to evaluate demographic and clinical parameters associated with the EQ-5D index of CC patients.

RESULTS

A total of 200 CC patients (137 newly referred with CC and 63 refractory or unexplained CC [RUCC] patients), 800 non-cough controls, and 799 healthy controls were analyzed. The EQ-5D index of CC patients was significantly lower than that of non-cough controls or healthy controls (0.82 ± 0.14 vs 0.92 ± 0.14/0.96 ± 0.08; P < 0.001, respectively). The index was also associated with older age (≥ 60 years), female sex, and comorbidities such as asthma or depression. Among the patients with CC, the index was significantly lower in patients with RUCC than in those with newly referred CC, being treated with codeine or cough neuromodulators, or with cough-related fatigue. In Spearman analyses, the EQ-5D index correlated with cough-specific quality of life and cough severity scores, not with throat sensation or cough trigger scores.

CONCLUSIONS

The HRQoL impairment of CC patients was associated with older age, female sex, and comorbidities but it was also affected by cough severity, complications, treatments, and treatment responses. Longitudinal studies are warranted to further understand and improve the HRQoL of CC patients.

Codeine prescription pattern and treatment responses in patients with chronic cough: a routinely collected institutional database analysis

Background

Codeine has been long used as an antitussive drug in several countries. However, a prescription pattern of codeine, such as dose or treatment duration, has not been reported in detail. Furthermore, there is few scientific evidence on the efficacy and safety. We aimed to examine codeine prescription pattern and explore treatment response in patients with chronic cough in real-world practice.

Methods

This was a retrospective cohort analysis of patients with chronic cough who were newly referred to tertiary allergy and asthma clinics between July 2017 and July 2018. Routinely collected electronic healthcare records (EHRs), including medical notes, prescriptions, and outpatient visits, were analyzed. Codeine prescription records were examined for duration, mean daily dose, and 1-year cumulative dose. Codeine responses were evaluated by manual EHR reviews.

Results

Among a total of 1,233 newly referred patients with chronic cough, 666 were prescribed codeine for a median [interquartile range (IQR)] of 27.5 days (IQR 14-60 days); the median daily dose was 30 mg/year (IQR 21.6-30 mg/year), and the 1-year cumulative dose was 720 mg/year (IQR 420-1,800 mg/year). About 14.0% of patients were prescribed codeine for >8 weeks; they were older and had a longer cough duration, throat abnormal sensation and less dyspnea than patients prescribed codeine for ≤8 weeks or who did not receive codeine. Codeine prescription and duration was positively associated with the number of other cough-related medications, diagnostic tests, or outpatient visits. Cough status change was noted in 61.3% of codeine-prescribed patients (as 'improved' in 40.1% and 'not improved' in 21.2%), but not documented in 38.7%. Side effects were described in 7.8%.

Conclusions

Codeine prescription may be frequent and chronic in real-world practice of patients with chronic cough, despite the lack of robust clinical evidence on the efficacy. High prescription rates suggest unmet clinical needs. Prospective studies are warranted to identify codeine treatment responses and safety, and to build up clinical evidence to guide appropriate use of narcotic antitussives.

[Chronic cough]

Coughing is an important protective reflex of the respiratory tract and primarily serves clearance of the bronchial system. It is also an exceptionally common symptom in outpatient care that can be an expression of a variety of diseases. Coughing duration of longer than 8 weeks is referred to as chronic cough. A structured, often interdisciplinary diagnostic process is essential. The aim here is to identify causal treatment options, avoiding overdiagnosis and simultaneously not overlooking severe illness. This article discusses current diagnostic procedures, important differential diagnoses and possible treatment options.

Somatically evoked cough responses help to identify patients with difficult-to-treat chronic cough: a six-month observational cohort study

BACKGROUND

Recently we identified in patients with chronic cough a sensory dysregulation via which the urge-to-cough (UTC) or coughing are evoked mechanically from "somatic points for cough" (SPCs) in the neck and upper trunk. We investigated the prevalence and the clinical relevance of SPCs in an unselected population of patients with chronic cough.

METHODS

From 2018 to 2021, symptoms of 317 consecutive patients with chronic cough (233 females) were collected on four visits (V1-V4) 2 months apart at the Cough Clinic of the University Hospital in Florence (I). Participants rated the disturbance caused by the cough (0-9 modified Borg Scale). We attempted to evoke coughing and/or UTC using mechanical actions in all participants who were subsequently categorised as responsive (somatic point for cough positive, SPC+) or unresponsive (SPC-) to these actions. An association was established between chronic cough and its commonest causes; treatments were administered accordingly.

FINDINGS

169 patients were SPC+ and had a higher baseline cough score (p < 0.01). In most of the patients, the treatments reduced (p < 0.01) cough-associated symptoms. All patients reported a decrease (p < 0.01) in cough score at V2 (from 5.70 ± 1.4 to 3.43 ± 1.9 and from 5.01 ± 1.5 to 2.74 ± 1.7 for SPC+ and SPC- patients respectively). However, whilst in SPC- patients the cough score continued to decrease indicating virtually complete cough disappearance at V4 (0.97 ± 0.8), in SPC+ patients this variable remained close to V2 values during the entire follow-up.

INTERPRETATION

Our study suggests that the assessment of SPCs may identify patients whose cough is unresponsive and are eligible for specific treatments.

FUNDING

This work was funded by an unrestricted grant from Merck (Italy).

Yardstick for managing cough, part 1: In adults and adolescent patients older than 14 years of age

Nationwide statistics in the United States and Australia reveal that cough of undifferentiated duration is the most common complaint for which patients of all ages seek medical care in the ambulatory setting. Management of chronic cough is one of the most common reasons for new patient visits to pulmonologists. Because symptomatic cough is such a common problem and so much has been learned about how to diagnose and treat cough of all durations but especially chronic cough, this 2-part yardstick has been written to review in a practical way the latest evidence-based guidelines most of which have been developed from recent high quality systematic reviews on how best to manage cough of all durations in adults, adolescents, and children. In this manuscript, part 1 of the 2-part series, we provide evidence-based, and expert opinion recommendations on the management of chronic cough in adult and adolescent patients (>14 years of age).

The Relationship Between Chronic Cough and Laryngopharyngeal Reflux

Chronic cough is multifactorial in origin, may affect quality of life adversely, and often poses a diagnostic challenge for physicians. Laryngopharyngeal reflux (LPR) is one common contributing factor for chronic cough, but the mechanism by which reflux causes cough remains unclear. Research investigating the relationship between chronic cough and LPR has focused largely on reflux from the perspective of gastroenterology, rather than otolaryngology.

OBJECTIVE

The purpose of our study was to investigate the relationship between chronic cough and LPR by using the objective results of 24-hour pH impedance studies.

METHODS

We conducted a retrospective chart review of all patients who presented to the voice center of the senior author (RTS) with a chief complaint of chronic cough and no previous diagnosis of reflux. Patient demographics, past medical history, laboratory data, and exam findings during the initial visit from 2015 to 2020 and at follow-up were analyzed.

RESULTS

We identified 28 patients who presented with a chief complaint of chronic cough and who had not been diagnosed with or treated for reflux previously. Twenty-three had additional risk factors for chronic cough (asthma, chronic sinusitis, and bronchial schwannoma). All 28 had findings consistent with LPR upon exam. Treatment with reflux medications and lifestyle modification decreased the reflux finding score significantly from 11.39 to 9.21 (P= 0.005). Of all, 60.7% of patients reported subjective improvement in cough symptoms. The cough had improved in 50.0% and had resolved completely in 10.7%. Patients with VF paresis were less likely to report improvement in their cough. Further workup was performed for the 11 patients who had cough that did not resolve completely after reflux treatment. Detectable levels of antimycoplasma antibodies were found in nine patients, and antipertussis antibodies were found in two patients. Six patients followed up after a course of clarithromycin, three of whom had experienced improvement in their cough.

CONCLUSIONS

Our findings suggest that LPR may be a prevalent contributing or etiologic factor for chronic cough. The expected improvement after initiating reflux treatment is 60% at 3 months. Cough resolved completely in 10% of patients at 4 months. Nonresponders may have other contributing causes of cough, including esophageal dysmotility, mycoplasma, pertussis, and other contributors. Further studies are needed to confirm or refute these findings.

Diagnostic yield of chest radiograph in management of adults with difficult-to-treat chronic cough-retrospective study

Background

Chest radiograph (CXR) is a routine imaging test in adults with chronic cough (CC), while value of thoracic computed tomography (CT) in these patients is still a matter of discussion. The aims of the study were to assess the diagnostic yield of CXR and to evaluate the impact of thoracic CT on management of patients with difficult-to-treat CC referred to our cough clinic.

Methods

The retrospective analysis of paired CXR and CT results was performed in 189 consecutive adults treated due to CC between 2015-2019 in our cough clinic. CC was defined as cough >8 weeks being the main or isolated ailment. The sensitivity, specificity, negative/positive predictive value (NPV, PPV) and diagnostic accuracy of CXR were calculated based on chest CT scan as the "gold standard". Only those CT scans which revealed abnormalities potentially related to CC and were associated with the changes in further diagnostic or therapeutic approach were construed as relevant CT findings during final analysis.

Results

The median age of patients (male/female ratio 53/136) was 58 years (IQR 44-67), only 6 subjects (3.0%) were active smokers, median CC duration was 48 months (IQR 24-120). CXR revealed abnormal findings in 23/189 (12.2%) patients. Normal CXR was confirmed by CT in 141 subjects (141/166; 84.9%). In 25/166 (15.1%) patients, CT showed abnormalities that could explain the cause of CC and changed either the diagnostic protocol or therapy. In patients with abnormal CXR, CT confirmed abnormal findings in 8 cases (8/23, 34.8%). The sensitivity, specificity, PPV, NPV, diagnostic accuracy were 24.2%, 90.4%, 34.8%, 84.9% and 78.8%, respectively.

Conclusions

CXR shows a limited diagnostic yield in adults with difficult-to-treat CC referred to cough clinic. Chest CT scan may add significant data impacting the diagnostic and therapeutic approach in these patients.

Health-related experiences of adults with chronic cough: Empirical research mixed methods

AIM

To describe adults' health-related experiences with chronic cough.

DESIGN

Survey and interviews.

METHODS

Participants completed questionnaires and interviews, to explore chronic cough's impact and management.

DATA SOURCES

Patients aged 18-85 years with at least three cough-related encounters within 56-120 days.

RESULTS

Forty-one patients were surveyed. Mean cough severity was 4.5 (scale 0-9). Chronic cough-related problems included embarrassment (66%), fatigue (56%), and anxiety or depression (49%). Testing was judged insufficient by 44%. Only 28% were satisfied with treatment; 20% reported abandoning treatment due to ineffectiveness. Interview themes (N = 30) included frustration with diagnostic uncertainty, and feelings of therapeutic futility. Some reported psychological distress. Work and socializing were commonly disrupted.

CONCLUSION

Diagnostic uncertainty, perceived limitations of testing, and treatment failures suggest needs for better approaches to evaluating and treating chronic cough. Special attention to identifying and addressing mental health issues appears warranted.

Healthcare-Seeking Behaviour Due to Cough in Finnish Elderly: Too Much and Too Little

INTRODUCTION

Cough-related healthcare-seeking has not been studied specifically in the elderly, although chronic cough is most prevalent among them. We studied the frequencies and predictors of any (≥ 1) and repeated (≥ 3) doctor's visits due to any cough episode during the past year, and due to the current cough episode.

METHODS

This was a cross-sectional email survey among a Finnish community-based elderly population. Participants with current cough and age ≥ 64 years were included in the analyses (n = 1109).

RESULTS

The proportions of participants with ≥ 1 and ≥ 3 cough-related doctor's visits during the past year were 25.9% and 7.1%, respectively. Repeated visitors accounted for 55.9% of the visits during the past year. These visits first increased with cough duration but decreased after 5 years. In the multivariate analysis, bronchiectasis [aOR 3.22 (CI95% 1.08-9.58)], asthma [2.62 (1.56-4.40)], chronic sputum production [1.61 (0.94-2.76)], low self-assessed health status [1.40 (1.04-1.88)] and Leicester Cough Questionnaire total score [1.34 per tertile (1.10-1.62)] predicted repeated cough-related doctor's visits during the past year. The proportions of ≥ 1 and ≥ 3 doctor's visits due to current cough were 31.8% and 15.5%, respectively. Among participants with current chronic cough, 60.1% had not visited a doctor.

CONCLUSION

A minority of participants accounted for most of the cough-related doctor's visits during the past year, whereas most participants with chronic cough had never sought medical help for it. The heavy healthcare users were not those with the longest cough episodes. Repeated visitors due to cough were characterised by chronic phlegmy respiratory conditions, and quality-of-life impairment.

Canadian Health Care Professionals' Familiarity with Chronic Cough Guidelines and Experiences with Diagnosis and Management: A Cross-Sectional Survey

INTRODUCTION

Educational programs on chronic cough may improve patient care, but little is known about how Canadian physicians manage this common debilitating condition. We aimed to investigate Canadian physicians' perceptions, attitudes, and knowledge of chronic cough.

METHODS

We administered a 10-min anonymous, online, cross-sectional survey to 3321 Canadian physicians in the Leger Opinion Panel who managed adult patients with chronic cough and had been in practice for > 2 years.

RESULTS

Between July 30 and September 22, 2021, 179 physicians (101 general practitioners [GPs] and 78 specialists [25 allergists, 28 respirologists, and 25 ear/nose/throat specialists]) completed the survey (response rate: 5.4%). In a month, GPs saw a mean of 27 patients with chronic cough, whereas specialists saw 46. About one-third of physicians appropriately identified a duration of > 8 weeks as the definition for chronic cough. Many physicians reported not using international chronic cough management guidelines. Patient referrals and care pathways varied considerably, and patients frequently experienced lost to follow-up. While physicians endorsed nasal and inhaled corticosteroids as common treatments for chronic cough, they rarely used other guideline-recommended treatments. Both GPs and specialists expressed high interest in education on chronic cough.

CONCLUSION

This survey of Canadian physicians demonstrates low uptake of recent advances in chronic cough diagnosis, disease categorization, and pharmacologic management. Canadian physicians also report unfamiliarity with guideline-recommended therapies, including centrally acting neuromodulators for refractory or unexplained chronic cough. This data highlights the need for educational programs and collaborative care models on chronic cough in primary and specialist care.

Mobile application-based oximetry: a potential toolfor appropriate referral of patients with respiratory symptoms examined via telemedicine

OBJECTIVE

To calculate the positive likelihood ratio to determine whether telemedicine is able to optimize referral to the emergency department.

METHODS

Unicenter study with 182 consecutive patients admitted to Hospital Israelita Albert Einstein due to respiratory symptoms. All patients were submitted to oxygen saturation measurement using the standard method Welch Allyn finger device vital sign monitor and a 2-minute evaluation (Binah.ai mobile application). The reproducibility of oxygen saturation measurements made with both methods was investigated using interclass correlation coefficients and analysis of dispersion. Bland-Altman plots were constructed and kappa concordance coefficients used to examine data normality. Accuracy was also estimated.

RESULTS

Oxygen saturation measurement differences between methods were ≤2% in more than 85% of cases. The mean difference (bias) between methods was near zero (0.835; Bland-Altman analysis). Oxygen saturation measurements made using the Binah.ai mobile application had an average ability to detect patients with altered oxygen saturation levels compared to the conventional method (ROC analysis). The positive likelihood ratio of the mobile application was 6.23.

CONCLUSION

Mobile applications for oxygen saturation measurement are accessible user-friendly tools with moderate impact on clinical telemedicine evaluation of patients with respiratory symptoms, and may optimize referral to the emergency department.

Demographic, clinical, and patient-reported outcome data from 2 global, phase 3 trials of chronic cough

BACKGROUND

The current characterization of patients with refractory or unexplained chronic cough (RCC and UCC, respectively) primarily stems from relatively small clinical studies.

OBJECTIVE

To report the baseline medical history and clinical characteristics of individuals with RCC or UCC who were enrolled in COUGH-1 and COUGH-2, 2 large, global, phase 3 trials of gefapixant, a P2 × 3-receptor antagonist.

METHODS

Adults with a chronic cough lasting for more than 1 year, diagnosis of RCC or UCC, and score greater than 40 mm on a 100-mm cough severity visual analog scale at both screening and baseline were eligible for enrollment. Demographics, medical history, and cough characteristics were collected at baseline. Cough-related measures included objective cough frequency, cough severity visual analog scale, Leicester Cough Questionnaire, and Hull Airway Reflux Questionnaire. The data were summarized using descriptive statistics.

RESULTS

Of 2044 participants, 75% were women; mean age was 58 years, and mean cough duration was approximately 11 years. Among all participants, 73% were previously diagnosed with asthma, gastroesophageal reflux disease, or upper airway cough syndrome. The mean Leicester Cough Questionnaire total score was 10.4, with domain scores reflecting impaired cough-specific quality of life across physical, psychological, and social domains. The mean Hull Airway Reflux Questionnaire score was 39.6, with some of the most burdensome reported items being consistent with features of cough-reflex hypersensitivity. Participant characteristics and cough burden were comparable across geographic regions.

CONCLUSION

Participants with RCC or UCC had characteristics consistent with published demographics associated with chronic cough. These data reflect a global population with burdensome cough of long duration and substantial impairment to quality of life.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: COUGH-1, NCT03449134 (https://www.

CLINICALTRIALS

gov/ct2/show/NCT03449134); COUGH-2, NCT03449147 (https://clinicaltrials.gov/ct2/show/NCT03449147).

Relationship Between COPD and GERD: A Bibliometrics Analysis

Purpose

A growing body of evidence links chronic obstructive pulmonary disease (COPD) to gastroesophageal reflux disease (GERD). In spite of the lack of understanding of the specific cause-effect relationship between COPD and GERD, GERD has been shown to be a significant predictor of acute exacerbations of COPD. In this study, we examined the evolution of the relationship between COPD and GERD over the past decades and provided valuable insights into this topic.

Methods

The Web of Science Core Collection (WoSCC) was searched since its inception until 19 August 2022 to obtain publications related to COPD and GERD. The data was analyzed in Microsoft Excel (version 2021), HisCite (version 2.1), Scimago Graphica (version 1.0.23), VOSviewer (1.6.17), and CiteSpace (version 5.8.R3).

Results

We extracted 545 documents from the WoSCC database. Since 2002, there have been rapid increases in publications. Among countries and institutions, the United States and the University of Manchester were most prolific. The most cited journal was Chest, while Respiratory Medicine had the most publications. Among 2870 related authors, Hasenfuss, Gerd, Lange, Peter, and Martinez, Gerd were the top 3 contributing authors in this field. Aside from "gastroesophageal reflux disease" and "chronic obstructive pulmonary disease", the terms "quality of life", "cough", and "inflammation" were frequently occurred in the title and abstract of articles. Keywords co-occurrence overlay visualization indicated that "refractory chronic cough" was hot topics in recent years.

Conclusion

Research on COPD and GERD has flourished, and its content topics have become more in-depth over time. In the future, this hot topic deserves more attention.

Validation and Meaningful Change Thresholds for an Objective Cough Frequency Measurement in Chronic Cough

PURPOSE

Objective cough frequency is used to assess efficacy of chronic cough (CC) treatments. The objective of this study was to explore the relationship between objective cough frequency and cough-specific patient-reported outcomes (PROs) and estimate a clinically meaningful change threshold (MCT) for objective cough frequency.

METHODS

Data collected in a phase 2b study in participants with refractory or unexplained CC were used to investigate the relationship between 24-h cough frequency (measured using an ambulatory cough monitor) and cough-specific PROs (i.e., cough severity visual analog scale, cough severity diary, Leicester Cough Questionnaire). Convergent validity was assessed using Spearman ρ. An MCT for 24-h cough frequency was estimated using the patient global impression of change (PGIC) scale as an anchor.

RESULTS

Correlations between 24-h cough frequency and cough-specific PROs at baseline, Week 4, and Week 12 were significant (P < 0.0001) but low to moderate in strength (ρ = 0.30-0.58). Participants categorized as very much improved/much improved (i.e., PGIC of 1 or 2) or minimally improved (i.e., PGIC of 3) had mean 24-h cough frequency reductions of 55% and 30%, respectively. Receiver operating characteristic curve analysis suggested that a 24-h cough frequency reduction of 38% optimizes sensitivity and specificity for predicting a PGIC score of 1-3.

CONCLUSION

Objective 24-h cough frequency is significantly associated with cough-specific PROs, but cough frequency and PROs most likely capture distinct aspects of CC. A ≥ 30% reduction in 24-h cough frequency is a reasonable MCT to define treatment response in CC clinical trials.

Narrative Review of the Mechanisms and Treatment of Cough in Asthma, Cough Variant Asthma, and Non-asthmatic Eosinophilic Bronchitis

Chronic cough is a debilitating condition affecting 10-12% of the general population and is one of the leading causes for referral to secondary care. Many conditions have been associated with chronic cough, including asthma, gastro-esophageal reflux disease and upper airways cough syndrome. Inflammatory airway conditions including cough variant asthma (CVA) and non-asthmatic eosinophilic bronchitis (NAEB) contribute to a significant proportion of presentations with chronic cough, with differing diagnostic criteria and different responses to commonly used asthma therapy for their respective diagnoses. Mechanistic studies in both animal models and humans have identified increased neuronal sensitivity and subsequent central sensitization. These mechanisms include inflammatory-mediated nociceptor sensitization and alterations of afferent nerve terminal excitability, phenotypic changes in the vagal afferent neurons over time, and central neuroplasticity resulting from increased synaptic signalling from peripheral afferents. The aim of this review is to discuss the mechanisms, neurophysiology, and management approaches currently available for patients presenting with chronic cough with underlying asthma, CVA, and NAEB and to shed a light on areas of further research required to elucidate the mechanisms of cough in this patient population.

Impact of productive and dry chronic cough on mortality in the Canadian Longitudinal Study on Aging (CLSA)

Background

Chronic cough is a common troublesome condition and accounts for a high burden on quality of life. Previous data investigating the mortality associated with chronic cough has been derived in patients with chronic bronchitis. No data exists on chronic dry cough. Therefore, we investigated if chronic dry and productive cough is independently associated with increased mortality.

Methods

The Canadian Longitudinal Study on Ageing (CLSA) is a prospective, nationally generalizable, stratified random sample of adults aged 45-85 years at baseline recruited between 2011-2015 and followed up three years later. Chronic cough was identified based on a self-reported daily cough in the last 12 months. Deaths were confirmed by the Ministry of Health and/or completion of descendent questionnaire by a family member. Models were investigated for dry and productive chronic cough and was adjusted for age, sex, smoking, body mass index (BMI), and respiratory diseases.

Results

Of the 30,016 participants, 4,783 (15.9%) reported chronic cough at baseline; 2,724 (57%) had a dry cough, and 2,059 (43%) had productive chronic cough. There was a total of 561 deaths between baseline and follow-up-1 (3 years later). There was a 49% higher risk of death in participants with chronic productive cough {adjusted odds ratio (aOR) 1.49 [95% confidence intervals (CI): 1.08-2.07]}, but not dry chronic cough [aOR 0.85 (0.60-1.20)]. The effects of chronic productive cough on mortality were persistent in those with no airflow obstruction [chronic productive cough aOR 1.90 (1.09-3.31)].

Conclusions

Chronic productive cough is associated with a higher risk of death, while chronic dry cough has no impact on mortality risk of death in middle-aged and older adults. This highlights the importance of careful evaluation of patients with chronic cough.

Prognosis of patients with laryngeal contact granuloma: Development and validation of RCGSG score

Objective

This study aimed to develop an objective and simple score for predicting the prognosis of patients with laryngeal contact granuloma (LCG) treated with local glucocorticoid injection combined with oral proton pump inhibitor (GI + PPI).

Methods

Cox regression analysis was used to analyze the effect of baseline variables on the prognosis of 507 patients with LCG treated with GI + PPI. An easy-to-apply RCGSG (Reflus, Cough, Gender, and Surgery in GI + PPI therapy) score was developed based on the independent risk factors selected by univariate and multivariate Cox regression analyses. The score was internally validated by receiver-operating characteristic curve, calibration curve, and decision curve analysis.

Results

After univariate and multivariate analyses, male gender (hazard ratio [HR] 0.546, p < .001), laryngopharyngeal reflux (HR 0.702, p = .001), chronic cough (HR 0.709, p = .001), and history of surgical resection (HR 0.433, p < .001) were found to be the independent risk factors affecting the prognosis of LCG. According to the score, the median cure time was 3 months (95% confidence interval [CI] 2.81-3.19) in the low-risk group, 4 months (95% CI 3.74-4.26) in the moderate-risk group, and 5 months (95% CI 4.76-5.24) in the high-risk group. The bootstrap method was used to plot calibration curves for internal validation.

Conclusion

The RCGSG score, developed based on laryngopharyngeal reflux, chronic cough, gender, and surgical resection history, has been internally verified to be a good predictor of the prognosis of patients with LCG receiving GI + PPI treatment.

Level of evidence

Level 4.

Clinical characteristics and drug utilisation patterns in patients with chronic cough: a retrospective cohort study using a Japanese claims database

BACKGROUND

Although unmet medical needs for better care of patients with chronic cough exist in Japan, epidemiological information about these patients and their treatments is very limited.

OBJECTIVES

To describe patient characteristics, underlying cough-related diseases and drug utilisation patterns in patients with chronic cough, and their changes over time.

METHODS

This large retrospective claims database study enrolled subjects with chronic cough, identified either by a specific diagnostic cough code for chronic cough (Population 1) or by multiple cough-related diagnostic codes spanning > 8 weeks (Population 2). Within Population 2, patients with each of the three most frequent diagnostic cough codes were analysed as subgroups. Patient characteristics, underlying cough-related diseases and utilisation patterns for drugs used for cough were documented at the index date, during the 6-month pre-index period and during the 12-month post-index period.

RESULTS

6,038 subjects were enrolled in the cohort (Population 1: N = 3,500; Population 2: N = 2,538). The mean age was 43.7 ± 12.2 years and 61.8% were women. The largest cough diagnosis subgroups in Population 2 were 'other coughs' (N = 1,444), 'cough-variant asthma' (N = 1,026) and 'atopic/allergic cough' (N = 105). At the index date, the most frequent underlying cough-related diseases were allergic rhinitis/nasal inflammation (N = 3,132; 51.9%), asthma (N = 2,517; 41.7%) and gastro-esophageal reflux disease (N = 829; 13.7%). At the index date, 4,860 participants (80.5%) were prescribed at least one cough-related treatment. 194 participants (4.0% of medication users) were prescribed central antitussives alone, principally in Population 1, and 2,331 (48.0%) were prescribed expectorants. Other frequently prescribed medications were antiallergic drugs (N = 2,588; 53.3%), antimicrobials (N = 1,627; 34.4%) and inhaled corticosteroids with long-acting beta-agonists (N = 1,404; 28.9%). Over time, cough diagnoses tended to be lost, with only 470 participants in Population 1 retaining a diagnostic code for chronic cough one year later. The frequency of underlying cough-related diseases was stable over time.

CONCLUSIONS

Patients in this cohort with chronic cough are most frequently identified by a diagnostic cough code for chronic cough, followed by codes for other coughs, cough-variant asthma and atopic cough. Chronic cough frequently presents with an underlying cough-related disease, most frequently allergic rhinitis/nasal inflammation, asthma or GERD. Medication prescription for the underlying cough-related diseases was generally appropriate.

Dyspnoea and cough in patients with systemic sclerosis-associated interstitial lung disease in the SENSCIS trial

OBJECTIVE

The aim of these analyses was to investigate the rate of decline in forced vital capacity (FVC) in patients with SSc-associated interstitial lung disease (SSc-ILD) with and without cough or dyspnoea in the SENSCIS trial.

METHODS

Patients in the SENSCIS trial were randomized to receive nintedanib or placebo. Subgroups with and without cough or dyspnoea at baseline were defined by responses to the St George's Respiratory Questionnaire.

RESULTS

At baseline, 114/575 patients (19.8%) did not have cough and 172/574 patients (30.0%) did not have dyspnoea. In the placebo group, the rate of FVC decline over 52 weeks was similar in patients with and without cough (-95.6 and -83.4 mL/year, respectively) or dyspnoea (-95.8 and -87.7 mL/year, respectively). The effect of nintedanib vs placebo on reducing the rate of FVC decline was numerically more pronounced in patients without than with cough [difference: 74.4 (95% CI -11.1, 159.8) vs 31.5 (-11.1, 74.1)] and without than with dyspnoea [79.8 (9.8, 149.7) vs 25.7 (-19.9, 71.3)], but interaction P-values did not indicate heterogeneity in the treatment effect between these subgroups (P = 0.38 and P = 0.20, respectively).

CONCLUSION

In the placebo group of the SENSCIS trial, the rate of FVC decline was similar irrespective of the presence of cough or dyspnoea at baseline. The effect of nintedanib on reducing the rate of FVC decline was numerically more pronounced in patients without than with cough or dyspnoea at baseline, but no statistically significant heterogeneity was observed between the subgroups.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT02597933.

The disease burden and quality of life of chronic cough patients in South Korea and Taiwan

Background

Chronic cough (CC) is a common condition, but the burden of CC in general populations remains largely unknown. This study aims to investigate the disease prevalence and burden among community-based CC patients in South Korea and Taiwan, using structured tools.

Methods

A population-based cross-sectional study uses data from the 2020 South Korea and Taiwan National Health and Wellness Survey (NHWS) as well as a CC survey conducted between January–February 2020 and March–April 2020, respectively. Health outcome measures included health-related quality of life (HRQoL), health state utilities, work productivity and activity impairment (WPAI), and measurement of depression, anxiety, and insomnia among CC patients.

Results

The weighted lifetime and 12-month prevalence of CC was 6.20% and 4.34% in South Korea, and 8.27% and 5.55% in Taiwan. Compared to matched non-CC controls, CC patients reported poorer HRQoL (SF-12v2) in terms of physical component summary (PCS) score (South Korea: 47.69 ± 7.68 vs. 50.08 ± 7.29; Taiwan: 48.58 ± 7.15 vs. 50.50 ± 7.30) and mental component summary (MCS) score (44.15 ± 8.85 vs. 46.28 ± 8.50; 42.44 ± 7.78 vs. 44.60 ± 8.08), health state utilities EQ-5D index (0.73 ± 0.23 vs. 0.82 ± 0.16; 0.82 ± 0.13 vs. 0.86 ± 0.14), and more visits to healthcare professionals (7.80 vs. 4.61; 6.09 vs. 4.20) (p < 0.05). In terms of WPAI, CC patients reported higher impairments in presenteeism (32.8% vs. 21.0%; 25.9% vs. 19.4%), total work productivity (36.2% vs. 22.3%; 27.7% vs. 20.6%), and total activity (34.2% vs. 23.2%; 27.7% vs. 20.3%) than non-CC controls (p < 0.001). CC patients in South Korea and Taiwan experienced anxiety, depression, and insomnia more than non-CC controls. Poorer health outcomes were associated with the severity of CC. Patients with severe CC (visual analogue scale [VAS]>4) in both nations reported lower PCS score (45.80 vs. 49.48; 47.41 vs. 49.22) and higher absenteeism (8.5% vs. 3.6%; 5.5% vs. 1.8%) than patients with mild CC (VAS≤4) (p < 0.05).

Conclusions

The findings revealed that the disease burden of CC in general populations of South Korea and Taiwan is considerable with a negative impact on the overall quality of life, social and work life, and psychological comorbidities and is significantly associated with increased severity of the CC. There is an unmet need for further treatment interventions for CC patients to relieve the burden of CC in both nations.

Referrals, Etiology, Prevalence, Symptoms and Treatments of Chronic Cough: A Survey of Allergy Specialists

BACKGROUND

Chronic cough (CC) affects 11% of the U.S. adult population and these patients experience persistent symptoms despite adherence to recommended treatment protocols. Further research is needed to identify effective therapies to treat CC.

OBJECTIVE

The purpose of this study was to describe the referral sources, etiology, prevalence, symptoms, and treatments for patients diagnosed with CC who present to allergy specialists (AS).

METHODS

An online survey was administered to 177 allergy specialists (AS). The survey queried each AS experiences with CC patients, including the prevalence of chronic cough, source of referrals for chronic cough patients, as well as perceived efficacy of treatments.

RESULTS

103 (58%) AS reported that the CC patients they treated were primarily female (58.26%), and Caucasian (65.69%). Family physicians, nurse practitioners, physician assistants and primary care internists were the most common source of referrals of CC patients to AS. 20% of the respondents reported a complete resolution of the symptoms for more than 75% of their CC patients. The top four "very common complaints" reported by CC patients were social embarrassment, loss of sleep, decreased quality of life, and sleep disruption. The top four most frequent treatments prescribed for CC were anti-reflux treatments, inhaled corticosteroids (ICS) alone or in combination with long acting beta-agonist (LABA), short acting bronchodilators, and first generation antihistamines. None of the therapies were rated "very effective" in greater than 50% of the CC patients.

CONCLUSION

The available treatments for CC do not effectively resolve the symptoms of this condition and additional treatments need to be developed.

Treatment with the P2X3-Receptor Antagonist Gefapixant for Acute Cough in Induced Viral Upper Respiratory Tract Infection: A Phase 2a, Randomized, Placebo-Controlled Trial

INTRODUCTION

Available therapies for acute cough, a condition frequently caused by a viral upper respiratory tract infection (URTI), have shown limited evidence of efficacy. Gefapixant, a P2X3-receptor antagonist, has demonstrated efficacy and safety in studies of the treatment of refractory or unexplained chronic cough, but its efficacy for treating acute cough has not been previously studied.

METHODS

This was a phase 2a, randomized, double-blind, placebo-controlled, parallel-group, pilot study. Healthy volunteers were randomized 1:1 to receive twice-daily gefapixant 45 mg or placebo and inoculated with human rhinovirus 16 to induce URTI and cough. Participants were observed while quarantined for 7 days after the start of treatment. The primary endpoint was awake cough frequency on day 3, which was objectively measured with a cough-recording device. Secondary endpoints included change from baseline to day 3 in subjective cough severity measures (cough severity visual analog scale, Cough Severity Diary) and cough-specific quality of life (Leicester Cough Questionnaire-acute).

RESULTS

Of the 46 participants who met inclusion criteria [mean (standard deviation, SD) age, 24.6 (6.5) years; females, n = 8], 40 completed the study (gefapixant, n = 21; placebo, n = 19). There was no significant difference in awake cough frequency on day 3 between the gefapixant and placebo groups [least squares means, 2.4 versus 2.7 coughs per hour, respectively; mean difference (95% confidence interval, CI), -0.3 (-2.3, 1.7); P = 0.75]. There were no significant between-group differences for any of the secondary endpoints. Peak cough frequency was low and occurred later in the study than expected (days 4-5). The safety profile was consistent with that of previous studies of gefapixant.

CONCLUSION

Compared with placebo, gefapixant did not reduce the frequency or severity of acute cough secondary to induced URTI. Induced viral URTI produced mild symptoms, including lower cough frequency than observed in previous studies of patients selected for acute cough associated with naturally occurring URTI.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03569033; EudraCT, 2017-000472-28; protocol number, MK-7264-013.

[Acute and chronic cough - differential diagnosis and treatment]

Cough is a frequent reason for consultation in the general practitioner's office. Most of the time, the symptom is harmless and self-limiting, as in the case of a banal cold cough, for example - however, serious diseases such as malignancies can also be the cause. Evaluation is therefore not always easy. This article presents a targeted and appropriate approach and discusses which treatments are recommended and effective.Acute and chronic cough are differentiated according to the duration of symptoms (up to 8 weeks/longer than 8 weeks). The most common cause of acute cough is a self-limiting viral infection of the upper respiratory tract; the most important differential diagnosis is community-acquired pneumonia. If there are no defined warning signs (red flags), the history and clinical examination are sufficient to establish the diagnosis in the case of an acute cough; medication is not necessary. In the case of a chronic cough, a chest X-ray is usually ordered and then further investigations are carried out in accordance with the most probable suspected diagnosis; probationary therapies are an important part of the workup. Coughs that are refractory to treatment or unexplained require individualised treatment (pharmacological, including off-label, non-pharmacological) and regular re-evaluation.

Patient-Reported Qualitative Analysis of Chronic Refractory Cough

PURPOSE

Chronic cough has been shown to be associated with adverse effects on quality of life. There is a paucity of research characterizing quality-of-life factors associated with chronic refractory cough (CRC), a cough persisting > 8 weeks despite evaluation and treatment of possible etiologies. The purpose of this study was to elucidate the features of CRC from the patient's perspective, including presenting symptoms, past treatment methods, and quality-of-life factors.

METHOD

Prospective semistructured interviews were conducted, recorded, and transcribed for 20 patients diagnosed with CRC. Exclusion criteria included lung disease, smoking history, laryngeal cancer, and neurological disease. Grounded theory analysis was completed on transcribed interviews.

RESULTS

Eighteen participants were women. Mean participant age was 53.5 years (SD = 1.41), and average cough duration was 52 months (SD = 71.6 months). Responses to 30 open-ended questions revealed four dominant themes with 24 subthemes.

CONCLUSIONS

CRC affects patient quality of life. Understanding patient perspective on CRC diagnosis and treatment helps providers better understand the physical and emotional toll CRC takes on patients. Findings suggest that providers should spend more time counseling patients regarding their treatment and diagnosis, as patients with CRC do not always fully understand their diagnosis and resort to self-blame.

Cough Presentation and Cough-Related Healthcare Utilization in Tertiary Care: Analysis of Routinely Collected Academic Institutional Database

PURPOSE

Routinely collected data (RCD) from electronic health records (EHR) are useful for studying disease epidemiology in the real world. We examined cough presentation and cough-related healthcare utilization using an academic institutional EHR database in Korea.

METHODS

In this retrospective cohort study, patients with subacute (3-8 weeks) or chronic cough (> 8 weeks in duration) referred to allergy and asthma clinics were studied. Cases were identified using the search term "cough" or "coughing," which is the chief complaint, in the data fields. Structured data, including demographics, medical history, symptoms, and diagnostic tests, were analyzed. Healthcare utilization was assessed for drug prescriptions, additional tests, or outpatient visits for 1 year.

RESULTS

Cough was the chief complaint in 13,223 cases (46.7%) among 28,312 new referrals for 8 years. A total of 3810 subacute and 7150 chronic cough patients were analyzed. The common demographic profile was middle-aged woman (mean age 52.1 years), reported in 63% of the cases. Cough was frequently accompanied by anterior nasal (about 50%), lower airway (30%), or acid reflux disease symptoms (20%), and by test abnormalities in chest X-rays (14%), spirometry (23%), or T2 inflammation markers (40%). Chronic cough patients frequently required additional tests (chest CT scan: 24%), drug prescriptions (codeine: 21.5% and oral steroids: 9.9%), and long-term healthcare utilization (16.0%) for 1 year.

CONCLUSIONS

Cough is a common chief complaint at allergy and asthma clinics, but the clinical presentation may be heterogeneous. Further studies are needed to understand long-term outcomes and reduce the disease burden.

Cough hypersensitivity and chronic cough

Chronic cough is globally prevalent across all age groups. This disorder is challenging to treat because many pulmonary and extrapulmonary conditions can present with chronic cough, and cough can also be present without any identifiable underlying cause or be refractory to therapies that improve associated conditions. Most patients with chronic cough have cough hypersensitivity, which is characterized by increased neural responsivity to a range of stimuli that affect the airways and lungs, and other tissues innervated by common nerve supplies. Cough hypersensitivity presents as excessive coughing often in response to relatively innocuous stimuli, causing significant psychophysical morbidity and affecting patients' quality of life. Understanding of the mechanisms that contribute to cough hypersensitivity and excessive coughing in different patient populations and across the lifespan is advancing and has contributed to the development of new therapies for chronic cough in adults. Owing to differences in the pathology, the organs involved and individual patient factors, treatment of chronic cough is progressing towards a personalized approach, and, in the future, novel ways to endotype patients with cough may prove valuable in management.

Evaluation of Cough Medication Use Patterns in Ambulatory Care Settings in the United States: 2003-2018

Using 2003−2018 National Ambulatory Medical Care Survey data for office-based visits and 2003−2018 National Hospital Ambulatory Medical Care Survey data for emergency department (ED) visits, we conducted cross-sectional analyses to examine cough medication (CM) use trends in the United States (US) ambulatory care settings. We included adult (≥18 years) patient visits with respiratory-infection-related or non-infection-related cough as reason-for-visit or diagnosis without malignant cancer or benign respiratory tumor diagnoses. Using multivariable logistic regressions, we examined opioid antitussive, benzonatate, dextromethorphan-containing antitussive, and gabapentinoid use trends. From 2003−2005 to 2015−2018, opioid antitussive use decreased in office-based visits (8.8% to 6.4%, Ptrend = 0.03) but remained stable in ED visits (6.3% to 5.9%, Ptrend = 0.99). In both settings, hydrocodone-containing antitussive use declined over 50%. Benzonatate use more than tripled (office-based:1.6% to 4.8%; ED:1.5% to 8.0%; both Ptrend < 0.001). Dextromethorphan-containing antitussive use increased in ED visits (1.8% to 2.6%, Ptrend = 0.003) but stayed unchanged in office-based visits (3.8% to 2.7%; Ptrend = 0.60). Gabapentinoid use doubled in office-based visits (1.1% in 2006−2008 to 2.4% in 2015−2018, Ptrend < 0.001) but was negligible in ED visits. In US office-based and ED ambulatory care settings, hydrocodone-containing antitussive use substantially declined from 2003 to 2018, while benzonatate use more than tripled, and dextromethorphan-containing antitussive and gabapentinoid use remained low (<3%).