Recommendations for the management of cough in adults

Risk factors of chronic cough in China: a systematic review and meta-analysis

OBJECTIVES

Risk factors of chronic cough in China have not been systematically analyzed and we hypothesized that risk factors of chronic cough might have distinct characteristics in China. Hence, we performed this meta-analysis focusing on the potential risk factors of chronic cough in China.

METHODS

We searched 7 databases for studies published before May 8, 2021. This systematic review was performed in accordance with the PRISMA checklist.

RESULTS

A total of 33 eligible articles were identified and included in this systematic review, and 28 studies were included in the meta-analysis. Our results showed that allergy (OR: 3.72; 95% CI: 1.85-7.47), nasal/sinusitis diseases (OR: 3.56; 95% CI: 2.02-6.29), family history of allergy (OR = 1.74; 95% CI: 1.59-1.90), family history of chronic respiratory diseases (OR = 1.67; 95% CI: 1.47-1.91), exposure to pollutants (OR = 1.60; 95% CI: 1.26-2.04), passive smoking (OR = 1.44; 95% CI: 1.32-1.57), and exposure to pets (OR = 1.37; 95% CI: 1.18-1.58) were risk factors for chronic cough in China.

CONCLUSIONS

Our study indicated some potential risk factors of chronic cough in China, which provides useful epidemiological information for managing chronic cough in China and is worthy as a reference for future global investigations.

Efficacy and safety of gefapixant, a P2X3 receptor antagonist, in refractory chronic cough and unexplained chronic cough (COUGH-1 and COUGH-2): results from two double-blind, randomised, parallel-group, placebo-controlled, phase 3 trials

BACKGROUND

Gefapixant is an oral P2X₃ receptor antagonist that has previously shown efficacy and safety in refractory chronic cough and unexplained chronic cough. We therefore aim to confirm the efficacy and safety of gefapixant in participants with refractory chronic cough and unexplained chronic cough.

METHODS

COUGH-1 and COUGH-2 were both double-blind, randomised, parallel-group, placebo-controlled, phase 3 trials. COUGH-1 was done in 156 sites in 17 countries and COUGH-2 in 175 sites in 20 countries. We enrolled participants who were 18 years or older with a diagnosis of refractory chronic cough or unexplained chronic cough of 1 year duration or more. Participants were also required to have a cough severity visual analogue scale score of 40 mm or more at screening and baseline. Eligible participants were randomly allocated (1:1:1), using a computer-generated allocation schedule, to one of three treatment groups: placebo, gefapixant 15 mg twice per day, or gefapixant 45 mg twice per day. All study treatments were given orally. Participants were treated over a 12-week main study period in COUGH-1 and a 24-week main study period in COUGH-2; followed by extension periods for a total of up to 52 weeks of treatment in both trials. The primary outcome was placebo-adjusted mean change in 24-h cough frequency at 12 weeks in COUGH-1 and 24 weeks in COUGH-2. Both studies were registered with ClinicalTrials.gov, NCT03449134 (COUGH-1) and NCT03449147 (COUGH-2).

FINDINGS

From March 14, 2018, (first participant screened) to July 26, 2019, (last participant screened) 732 patients were recruited in COUGH-1 and 1317 in COUGH-2. COUGH-1 randomly assigned and treated 730 participants (243 [33×3%] with placebo, 244 [33×4%] with gefapixant 15 mg twice per day, and 243 [33×3%] with gefapixant 45 mg twice per day); COUGH-2 randomly assigned and treated 1314 participants (435 [33×1%] with placebo, 440 [33×5%] with gefapixant 15 mg twice per day, and 439 [33×4%] with gefapixant 45 mg twice per day). Participants were mostly female (542 [74×2%] of 730 in COUGH-1 and 984 [74×9%] of 1314 in COUGH-2). The mean age was 59×0 years (SD 12×6) in COUGH-1 and 58×1 years (12×1) in COUGH-2, and the mean cough duration was 11·6 years (SD 9·5) in COUGH-1 and 11·2 years (9·8) in COUGH-2. Gefapixant 45 mg twice per day showed significant reductions in 24-h cough frequency compared with placebo at week 12 in COUGH-1 (18·5% [95% CI 32·9-0·9]; p=0·041) and at week 24 in COUGH-2 (14·6% [26·1-1·4]; p=0·031). Gefapixant 15 mg twice per day did not show a significant reduction in cough frequency versus placebo in both studies. The most common adverse events were related to taste disturbance: ageusia (36 [4·9%] of 730 in COUGH-1 and 86 [6·5%] of 1314 in COUGH-2), dysgeusia (118 [16·2%] in COUGH-1 and 277 [21·1%] in COUGH-2), hypergeusia (3 [0·4%] in COUGH-1 and 6 [0×5%] in COUGH-2), hypogeusia (19 [2·6%] in COUGH-1 and 80 [6·1%] in COUGH-2), and taste disorder (28 [3·8%] in COUGH-1 and 46 [3·5%] in COUGH-2).

INTERPRETATION

Gefapixant 45 mg twice per day is the first treatment to show efficacy with an acceptable safety profile in phase 3 clinical trials for refractory chronic cough or unexplained chronic cough.

FUNDING

Merck Sharp & Dohme.

Efficacy and Safety of Eucalyptus for Relieving Cough: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives: To assess the efficacy and safety of Eucalyptus globulus Labill (Eucalyptus) on cough. Background: Cough is a common symptom of upper respiratory tract infections (URTIs) and bronchitis. Eucalyptus products are frequently used as over-the-counter cough medications but their efficacy and safety are uncertain. Methods: Randomized controlled trials (RCTs) investigating efficacy and safety of Eucalyptus for cough were systematically searched in electronic databases till February 2021. Two reviewers independently performed study selection, data extraction, and quality assessment. Clinical outcomes including improvement or resolution of overall cough symptoms, cough frequency (CF), and adverse events (AEs) of Eucalyptus were evaluated and analyzed using a random-effects model. Heterogeneity was evaluated using I² and chi-squared test. Results: Six RCTs with 1,857 participants with cough were included in this study. Most of the included studies used Eucalyptus in combination formula (four of six studies). Based on Cochrane's risk of bias criteria, three of six studies (50%) were rated low risk of bias, whereas the remaining were judged as high risk of bias. This study found that Eucalyptus products are more effective than placebo in terms of improvement or resolution of overall cough symptoms with relative risk 1.45 (95% confidence interval (95% CI) 1.26-1.67). Whereas all Eucalyptus formulae reduced CF with weighted mean difference 0.44 (95% CI 0.28-0.60), when compared with placebo. There are no serious AEs associated with Eucalyptus during treatment periods. Mild-to-moderate gastrointestinal symptoms were common AEs reported in a comparable study between Eucalyptus and control groups. Conclusion: The findings indicate that Eucalyptus products are safe for use in cough related to respiratory diseases such as URTIs and bronchitis. However, their efficacy is minimal and of uncertain clinical importance. Further high-quality studies are still necessary to confirm this finding.

Chronic respiratory disease in adult outpatients in three African countries: a cross-sectional study

BACKGROUND: The greatest burden of chronic respiratory disease is in low- and middle-income countries, with recent population-based studies reporting substantial levels of obstructive and restrictive lung function.OBJECTIVE: To characterise the common chronic respiratory diseases encountered in hospital outpatient clinics in three African countries.METHODS This was a cross-sectional study of consecutive adult patients with chronic respiratory symptoms (>8 weeks) attending hospital outpatient departments in Ethiopia, Kenya and Sudan. Patients were assessed using a respiratory questionnaire, spirometry and chest radiography. The diagnoses of the reviewing clinicians were ascertained.RESULT: A total of 519 patients (209 Kenya, 170 Ethiopia, 140 Sudan) participated; the mean age was 45.2 years (SD 16.2); 53% were women, 83% had never smoked. Reviewing clinicians considered that 36% (95% CI 32-40) of patients had asthma, 25% (95% CI 21-29) had chronic bronchitis, 8% (95% CI 6-11) chronic obstructive pulmonary disease (COPD), 5% (95% CI 4-8) bronchiectasis and 4% (95% CI 3-6) post-TB lung disease. Spirometry consistent with COPD was present in 35% (95% CI 30-39). Restriction was evident in 38% (95% CI 33-43). There was evidence of sub-optimal diagnosis of asthma and COPD.CONCLUSION: In Ethiopia, Kenya and Sudan, asthma, COPD and chronic bronchitis account for the majority of diagnoses in non-TB patients with chronic respiratory symptoms. The suboptimal diagnosis of these conditions will require the widespread use of spirometry.

Management of cough in patients with idiopathic interstitial lung diseases in primary care

Importance: Cough is a common symptom in idiopathic interstitial lung diseases (ILDs), there is little information of its management in primary care. The objective of this study was to explore the frequency of cough-related consultations and the medications prescribed to patients with ILDs in primary care. Methods: This retrospective cohort study used electronic medical records (EMR) from Manitoba primary care providers participating in the Manitoba Primary Care Research Network repository (2014–2019). Cough-related consults and the subsequent medications prescribed to patients with ILDs were identified in the EMR. Results: 295 patients with ILDs were identified, 73 (25%) of them had 141 cough-related consultations (mean 1.9, SD 1.3) during the period studied. In 50 (35%) of the consultations, patients were prescribed one or more of the following: inhaled bronchodilators (34%), nasal corticoids (18%), codeine/opiates (18%), antibiotics (14%), inhaled corticoids (14%), proton pump inhibitors (8%), cough preparations (6%), antihistamines (4%), and oral corticoids (2%). 13 (26%) subsequent cough-related consultations were identified within 6 months, mainly among patients who were prescribed cough preparations, nasal corticoids, antihistamines, and antibiotics. Conclusion: One-quarter of patients with ILDs consulted primary care due to cough, and about a third of them received a prescription to address potentially underlying causes of cough. Although further studies are required to explore the effect of the medications prescribed, recurrent cough consultations suggested that cough preparations, nasal corticoids, and antihistamines are among the least effective treatments. More research is needed to understand the causes and optimal treatment of cough in patients with ILDs.

Curbing the Cough: Multimodal Treatments for Neurogenic Cough: A Systematic Review and Meta-Analysis

OBJECTIVES/HYPOTHESIS

Neurogenic cough affects 11% of Americans and causes significant detriment to quality of life. With the advent of novel therapies, the objective of this review is to determine how procedural therapies (e.g., superior laryngeal nerve block) compare to other established pharmacologic and non-pharmacologic treatments for neurogenic cough.

METHODS

With the assistance of a medical librarian, a systematic review was performed using PICOS (patients, interventions, comparator, outcome, study design) format: adults with neurogenic cough receiving any pharmacologic or non-pharmacologic treatment for neurogenic cough compared to adults with neurogenic cough receiving any other relevant interventions, or treated as single cohorts, assessed with cough-specific quality of life outcomes, in all study designs and case series with ≥ 10 cases. Case reports, review articles, non-human studies, non-English language articles, and unavailable full-text articles were excluded.

RESULTS

There were 2408 patients with neurogenic cough in this review, treated with medical therapy (77%), speech therapy (19%), both medical and speech therapy (1%), and procedural therapy (3%). The included studies ranged from low to intermediate quality. Overall, most interventions demonstrated successful improvement in cough. However, the heterogeneity of included study designs precluded direct comparisons between intervention types.

CONCLUSION

This meta-analysis compared various treatments for neurogenic cough. Procedural therapy should be considered in the armamentarium of neurogenic cough treatments, particularly in patients refractory to, or intolerant of, the side effects of medical therapy. Lastly, this review illuminates key areas for improving neurogenic cough diagnosis, such as strict adherence to diagnostic and treatment guidelines, sophisticated reflux testing, and standardized, consistent outcome reporting. Laryngoscope, 132:107-123, 2022.

Chronic cough: new insights and future prospects

Chronic cough is defined in adults as a cough that lasts for ≥8 weeks. When it proves intractable to standard-of-care treatment, it can be referred to as refractory chronic cough (RCC). Chronic cough is now understood to be a condition of neural dysregulation. Chronic cough and RCC result in a serious, often unrecognized, disease burden, which forms the focus of the current review.The estimated global prevalence of chronic cough is 2-18%. Patients with chronic cough and RCC report many physical and psychological effects, which impair their quality of life. Chronic cough also has a significant economic burden for the patient and healthcare systems. RCC diagnosis and treatment are often delayed for many years as potential treatable triggers must be excluded first and a stepwise empirical therapeutic regimen is recommended.Evidence supporting most currently recommended treatments is limited. Many treatments do not address the underlying pathology, are used off-label, have limited efficacy and produce significant side-effects. There is therefore a significant unmet need for alternative therapies for RCC that target the underlying disease mechanisms. Early clinical data suggest that antagonists of the purinergic P2X3 receptor, an important mediator of RCC, are promising, though more evidence is needed.

Blood eosinophils as a predictor of treatment response in adults with difficult-to-treat chronic cough

There is lack of evidence on the role of blood eosinophil count (BEC) as a predictor of treatment response in patients with chronic cough. The study aimed to evaluate BEC as a predictor of treatment response in all non-smoking adults with chronic cough and normal chest radiograph referred to cough clinic and in a subgroup of patients with chronic cough due to asthma or non-asthmatic eosinophilic bronchitis (NAEB).

This prospective cohort study included 142 consecutive, non-smoking patients referred to our cough centre due to chronic cough. The management of chronic cough was performed according to the current recommendations. At least a 30-mm decrease of 100-mm visual analogue scale in cough severity and a 1.3 points improvement in Leicester Cough Questionnaire were classified as a good therapeutic response.

There was a predominance of females (72.5%), median age 57.5 years with long-lasting, severe cough (median cough duration 60 months, severity 55/100 mm). Asthma and NAEB were diagnosed in 47.2% and 4.9% of patients, respectively. After 12–16 weeks of therapy, a good response to chronic cough treatment was found in 31.0% of all patients. A weak positive correlation was demonstrated between reduction in cough severity and BEC (r=0.28, p<0.001). Area under the curve for all patients with chronic cough was 0.62 with the optimal BEC cut-off for prediction of treatment response set at 237 cells·µL⁻¹ and for patients with chronic cough due to asthma/NAEB was 0.68 (95% CI 0.55–0.81) with the cut-off at 150 cells·µL⁻¹.

BEC is a poor predictor of treatment response in adults with chronic cough treated in the cough centre.

Evaluation of blood eosinophil count has limited value in prediction of therapeutic response in patients with difficult-to-treat chronic coughhttps://bit.ly/3EjaYsZ

A History of Recurrent Episodes of Prolonged Cough as a Predictive Value for Determining Cough Variant Asthma in a Primary Care Setting

Background

Many patients visit primary care clinics with a complaint of cough. General practitioners (GPs) developed a list of the causative diseases of cough that can produce a patient's symptoms and signs. Then, the patients' medical histories were evaluated to determine whether the diagnosis of cough variant asthma (CVA) or post-infectious cough (PIC) could have been predicted.

Methods

We retrospectively investigated 195 outpatients with a complaint of cough. Medical histories of "recurrent episodes of prolonged cough" and "upper respiratory infection" were obtained during the initial visit. The accuracy of medical histories in predicting CVA and PIC was calculated on the area under the curve (AUC).

Results

Among eligible patients with cough, PIC was diagnosed in 99 patients (50.8%), CVA in 40 patients (20.5%), upper airway cough syndrome in 28 patients (14.4%), and chronic obstructive pulmonary disease in 11 patients (5.6%). Among the patients with CVA and those with PIC, 93% and 12%, respectively, had a history of recurrent episodes of prolonged cough. For the diagnosis of CVA, having a history of recurrent episodes of prolonged cough showed a moderately accurate AUC (0.76, 95% CI: 0.71-0.82). On the other hand, for the diagnosis of PIC, having no history of recurrent episodes of prolonged cough also showed a moderately accurate AUC (0.87, 95% CI: 0.82-0.92).

Conclusion

The medical history of recurrent episodes of prolonged cough is useful for the prediction of CVA as well as PIC.

The financial burden of treating patients presenting with acute and chronic cough

OBJECTIVE

Coughing is a common symptom and responsible for a large number of healthcare visits. This study aimed to characterize healthcare resource use and associated financial costs in people with acute or chronic cough.

METHODS

A retrospective cohort study using routine data from the UK National Health Service. Adults (≥18 years) were selected if they had a cough record between 1 March 2014 and 28 February 2015 and were classified by duration.

RESULTS

A cohort of 150,231 patients was identified, of whom 12,513 (8.3%) had chronic cough, 38,599 (25.7%) had an acute cough with more than one cough event, and 99,119 (66.0%) had acute cough with one event in the study year. Resource use and combined costs of all healthcare contacts differed between cough groups. The healthcare cost per person-year in patients with a single record of acute cough was £739; for those with chronic cough, the cost was £3,663.

CONCLUSIONS

Patients with cough represented a substantial financial burden to the NHS. It was difficult to discern the specific portion of treatment associated with cough itself. However, people with chronic cough were associated with substantially increased healthcare use and costs than were those with acute cough.

Performance of fractional exhaled nitric oxide in predicting response to inhaled corticosteroids in chronic cough: a meta-analysis

Background. Chronic cough is a disabling condition with a high proportion of diagnostic and therapeutic failures. Fractional exhaled nitric oxide (FeNO) has been considered a useful biomarker for predicting inhaled corticosteroids (ICS) response. We evaluated the relationship between FeNO and ICS response in chronic cough by performing a systematic review with meta-analysis.Methods. PubMed, Web of Science, Scopus and EMBASE databases were systematically searched. Differences were expressed as Odds Ratio (OR) with 95% confidence intervals (95%CI). Pooled sensitivity, specificity, positive (PLR) and negative likelihood ratio (NLR), and area under the hierarchical summary receiver operating characteristic curve (HSROCAUC) were estimated.Results. Nine articles on 740 chronic-cough patients showed that the response rate to ICS was 87.4% (95%CI: 83.8-91.0) in 317 patients with a high FeNO and 46.3% (95%CI: 41.6-51.0) in 423 controls, with an attributable proportion of 47.0% and a diagnostic OR of 9.1 (95%CI: 3.7-22.4, p < .001). The pooled estimate of diagnostic indexes resulted in a sensitivity of 68.5% (95%CI: 46.7-84.4) and specificity of 81.9% (95%CI: 63.0-92.3), with a HSROCAUC of 0.82 (95%CI: 0.64-0.90). In a realistic scenario with a pre-test probability set at 30%, based on a pooled PLR of 3.79 (95%CI: 1.24-7.47) and NLR of 0.38 (95%CI: 0.22-0.66), the post-test probability was 62% with a high FeNO and 14% if the test was negative. Subgroup analyses confirmed a better performance for the recommended FeNO cut-off greater than 25 ppb. Meta-regression and sensitivity analyses showed no impact of major demographic and clinic variables on results.Conclusions. A high FeNO before starting ICS therapy may help identify chronic-cough patients responding to treatment, with a better performance ofhigher cut-off values. Further studies are needed to evaluate the real usefulness of this biomarker to guide cough therapy and optimise strategies in different healthcare settings (community, hospital, rehabilitation).Key messagesChronic cough is a disabling condition with a high proportion of diagnostic and therapeutic failures.Fractional exhaled nitric oxide (FeNO) may be a useful biomarker for identifying chronic cough patients who respond to steroid treatment.A FeNO cut-off lower than 25 ppb should be considered irrelevant for this clinical application.

WAO-ARIA consensus on chronic cough - Part II: Phenotypes and mechanisms of abnormal cough presentation - Updates in COVID-19

BACKGROUND

Chronic cough can be triggered by respiratory and non-respiratory tract illnesses originating mainly from the upper and lower airways, and the GI tract (ie, reflux). Recent findings suggest it can also be a prominent feature in obstructive sleep apnea (OSA), laryngeal hyperresponsiveness, and COVID-19. The classification of chronic cough is constantly updated but lacks clear definition. Epidemiological data on the prevalence of chronic cough are informative but highly variable. The underlying mechanism of chronic cough is a neurogenic inflammation of the cough reflex which becomes hypersensitive, thus the term hypersensitive cough reflex (HCR). A current challenge is to decipher how various infectious and inflammatory airway diseases and esophageal reflux, among others, modulate HCR.

OBJECTIVES

The World Allergy Organization/Allergic Rhinitis and its Impact on Asthma (WAO/ARIA) Joint Committee on Chronic Cough reviewed the current literature on classification, epidemiology, presenting features, and mechanistic pathways of chronic cough in airway- and reflux-related cough phenotypes, OSA, and COVID-19. The interplay of cough reflex sensitivity with other pathogenic mechanisms inherent to airway and reflux-related inflammatory conditions was also analyzed.

OUTCOMES

Currently, it is difficult to clearly ascertain true prevalence rates in epidemiological studies of chronic cough phenotypes. This is likely due to lack of standardized objective measures needed for cough classification and frequent coexistence of multi-organ cough origins. Notwithstanding, we emphasize the important role of HCR as a mechanistic trigger in airway- and reflux-related cough phenotypes. Other concomitant mechanisms can also modulate HCR, including type2/Th1/Th2 inflammation, presence or absence of deep inspiration-bronchoprotective reflex (lower airways), tissue remodeling, and likely cough plasticity, among others.

Upper airway cough syndrome may be the main cause of chronic cough in Japan: a cohort study

BACKGROUND

Upper airway cough syndrome (UACS) is generally considered a common cause of chronic cough but remains poorly recognised in Japan.

OBJECTIVE

This study aimed to assess whether UACS was a common cause of chronic cough in Japan, as is true in other countries. Interview and examination items were evaluated for their potential use in UACS diagnosis.

METHODS

All patients with chronic cough were preliminarily diagnosed with bronchial asthma, UACS, gastroesophageal reflux disease, or postinfectious prolonged cough, based on interviews and examinations. Treatment centred on nasal steroids was administered to the UACS group and standard treatment to the other groups. The observation period lasted 4 weeks. The subjective cough score at first diagnosis was set at 10, and the final diagnosis was made based on the treatment administered at the time the cough score had decreased to ≤2. The associations between the presence or absence of UACS and interview and examination items were statistically evaluated.

RESULTS

Among 230 patients with chronic cough, 146 were diagnosed with UACS-only. Multivariate logistic regression revealed that the assessment items 'awareness of mucus accumulating in the back of the throat', 'presence of abnormal echography findings', 'absence of associated coughing when exercising' and 'presence of coughing persisting after onset' were significantly correlated with the presence or absence of UACS (p < 0.05).

CONCLUSIONS

UACS may be the most common cause of chronic cough in Japan and may be effectively treated with nasal corticosteroids. Diagnosing UACS might be possible by selecting appropriate interview and examination items.

Heartburn as a Marker of the Success of Acid Suppression Therapy in Chronic Cough

Purpose

Gastro-oesophageal reflux disease (GORD) is commonly thought to play an important role in chronic cough and patients are often empirically treated with acid suppression therapy. We sought to investigate the response rate to acid suppression treatment in patients with and without heartburn attending two specialist cough clinics.

Methods

A retrospective review of 558 consecutive patients referred to two specialist cough clinics was performed (UK and USA). Patients who were treated with acid suppression were included and their documented response to treatment was collected. Binary logistic regression was used to ascertain the value of reported heartburn in predicting the response of chronic cough to acid suppression therapy.

Results

Of 558 consecutive referrals, 238 patients were excluded due to missing data or cough duration of < 8 weeks. The remaining 320 patients were predominantly female (76%), with mean age 61 yrs (± 13) and 96.8% non-smokers, with chronic cough for 36 (18–117) months. Of 72 patients with heartburn, 20 (28%) noted improvement in their cough with acid suppression, whereas of 248 without heartburn, only 35 (14%) responded. Patients reporting heartburn were 2.7 (95% C.I. 1.3–5.6) times more likely to respond to acid suppression therapy (p = 0.007).

Conclusion

In specialist cough clinics, few patients report a response of their chronic cough to acid suppression therapy. Nonetheless, heartburn is a useful predictor substantially increasing the likelihood of benefit.

Prostaglandin E2 sensitizes the cough reflex centrally via EP3 receptor-dependent activation of NaV 1.8 channels

Background

Cough hypersensitivity is a major characteristic feature associated with several types of cough, including chronic cough, but its underlying mechanisms remain to be fully understood. Inflammatory mediators, such as prostaglandin E₂ (PGE₂), have been implicated in both peripheral induction and sensitization of the cough reflex. In this study, using a conscious guinea pig model of cough, we investigated whether PGE₂ can sensitize the cough reflex via central actions and, if so, via which mechanisms.

Methods

All drugs were administered by intracerebroventricular (i.c.v.) route and whole-body plethysmograph set-up was used for both induction, using aerosolized citric acid (0.2 M), and recording of cough. Immunohistochemistry was performed to confirm the expression of NaV 1.8 channels in the nucleus tractus solitarius (nTS).

Results

We show that both PGE₂ and the non-selective EP1/EP3 agonist, sulprostone, dose-dependently enhanced the citric acid-induced cough (P ≤ 0.001, P ≤ 0.01, respectively). Pretreatment with the EP1 antagonist, ONO-8130, did not affect the sulprostone-induced cough sensitization, whilst the EP3 antagonist, L-798,106, dose-dependently inhibited this effect (P ≤ 0.05). Furthermore, treatment with either the EP2 agonist, butaprost or the EP4 agonist, L-902,688, had no effect on cough sensitization. Additionally, pretreatment with either the TRPV1 antagonist, JNJ-17203212 or the TRPA1 antagonist, HC-030031, alone or in combination, nor with the NaV 1.1, 1.2, 1.3, 1.4, 1.6 and 1.7 channel blocker, tetrodotoxin, had any effect on the cough. In contrast, pretreatment with the NaV 1.8 antagonist, A-803467, dose-dependently inhibited this effect (P ≤ 0.05). Furthermore, NaV 1.8 channels were shown to be expressed in the nTS.

Conclusion

Collectively, our findings show that PGE₂ sensitizes the cough reflex centrally via EP3 receptor-dependent activation of NaV 1.8 but independently of TRPV1,TRPA1 and TTX-sensitive sodium channel activation. These results indicate that PGE₂ plays an important role in central sensitization of the cough reflex and suggest that central EP3 receptors and/or NaVv 1.8 channels may represent novel antitussive molecular targets.

Graphical Abstract

Eliapixant (BAY 1817080), a P2X3 receptor antagonist, in refractory chronic cough: a randomised, placebo-controlled, crossover phase 2a study

BACKGROUND

ATP acting via P2X3 receptors is an important mediator of refractory chronic cough (RCC). This phase 2a double-blinded crossover study assessed the safety, tolerability and efficacy of eliapixant (BAY 1817080), a selective P2X3 receptor antagonist, in adults with RCC attending specialist centres.

METHODS

In period A, patients received placebo for 2 weeks then eliapixant 10 mg for 1 week. In period B, patients received eliapixant 50, 200 and 750 mg twice daily for 1 week per dose level. Patients were randomised 1:1 to period A-B (n=20) or B-A (n=20). The primary efficacy end-point was change in cough frequency assessed over 24 h. The primary safety end-point was frequency and severity of adverse events (AEs).

RESULTS

37 patients completed randomised therapy. Mean cough frequency fell by 17.4% versus baseline with placebo. Eliapixant reduced cough frequency at doses ≥50 mg (reduction versus placebo at 750 mg: 25% (90% CI 11.5-36.5%); p=0.002). Doses ≥50 mg also significantly reduced cough severity. AEs, mostly mild or moderate, were reported in 65% of patients with placebo and 41-49% receiving eliapixant. Cumulative rates of taste-related AEs were 3% with placebo and 5-21% with eliapixant; all were mild.

CONCLUSIONS

Selective P2X3 antagonism with eliapixant significantly reduced cough frequency and severity, confirming this as a viable therapeutic pathway for RCC. Taste-related side-effects were lower at therapeutic doses than with the less selective P2X3 antagonist gefapixant. Selective P2X3 antagonism appears to be a novel therapeutic approach for RCC.

Acute Exacerbation of Cough as a Precipitating Cause of Hypoxia in COVID-19 Patients

Kumar A, Kumar A, Kumar A, Sinha C, Kumar N, Singh PK. Acute Exacerbation of Cough as a Precipitating Cause of Hypoxia in COVID-19 Patients. Indian J Crit Care Med 2021;25(11):1324-1325.

Longitudinal analyses suggest a higher burden of self-reported influenza-like illness among women and girls in a rural community in western Kenya

Longitudinal studies that quantify influenza-like illness (ILI) burden while determining associated risk factors and intra-cluster correlation coefficients (ICCs) are scarce in Africa. This study aimed to identify longitudinal patterns of ILI and the associated independent variables while quantifying the burden by age and sex. We enrolled and followed 390 subjects nested within 92 households for 12 weeks, collecting weekly data on prespecified self-reported symptoms in a rural community in western Kenya. Using a standard case definition, reporting at least any four prespecified symptoms attained an ILI syndrome. Analyses related relationship between attaining ILI syndrome and independent variables using multilevel logistic regression models adjusting for age and sex. ICCs quantified clustering of ILI syndrome computed at different levels of data aggregation. Of the 4261 reports received, 592 (14%) registered an illness, with 278 (48%) of these attaining ILI syndrome. The 278 reports belonged to 176 (41%) subjects dwelling in 76 (83%) households. On average, each study subject and household experienced 1.6 and 3.7 episodes of ILI syndrome, respectively. Making a visit outside the local area of residence (Odds ratio (OR) =2.7, 95% CI 1.8, 4.1) and living in a cement-floored house (OR = 1.9, 95% CI 1.1, 3.3) independently predicted attaining ILI syndrome. Correcting for the population structure revealed an excess risk of 16% in attaining the syndrome among the study women and girls. Clustering of ILI syndrome was lowest at the individual level (ICC = 0.04) and slightly higher within households (ICC = 0.14), suggesting moderate household contextual influences. Regardless of the cause, we provide evidence of a potentially higher ILI syndrome burden among women and girls in our study area. Studies are needed to establish granular exposures defining the increasing risk of ILI syndrome associated with gender, making a visit outside the local sub-county of residence and living in a cement-floored house.

Revised Korean Cough Guidelines, 2020: Recommendations and Summary Statements

Cough is the most common respiratory symptom that can have various causes. It is a major clinical problem that can reduce a patient's quality of life. Thus, clinical guidelines for the treatment of cough were established in 2014 by the cough guideline committee under the Korean Academy of Tuberculosis and Respiratory Diseases. From October 2018 to July 2020, cough guidelines were revised by members of the committee based on the first guidelines. The purpose of these guidelines is to help clinicians efficiently diagnose and treat patients with cough. This article highlights the recommendations and summary of the revised Korean cough guidelines. It includes a revised algorithm for the evaluation of acute, subacute, and chronic cough. For a chronic cough, upper airway cough syndrome (UACS), cough variant asthma (CVA), and gastroesophageal reflux disease (GERD) should be considered in differential diagnoses. If UACS is suspected, first-generation antihistamines and nasal decongestants can be used empirically. In cases with CVA, inhaled corticosteroids are recommended to improve cough. In patients with suspected chronic cough due to symptomatic GERD, proton pump inhibitors are recommended. Chronic bronchitis, bronchiectasis, bronchiolitis, lung cancer, aspiration, intake of angiotensin-converting enzyme inhibitor, intake of dipeptidyl peptidase-4 inhibitor, habitual cough, psychogenic cough, interstitial lung disease, environmental and occupational factors, tuberculosis, obstructive sleep apnea, peritoneal dialysis, and unexplained cough can also be considered as causes of a chronic cough. Chronic cough due to laryngeal dysfunction syndrome has been newly added to the guidelines.

An open-label study of the tolerability and potential efficacy of memantine for treating refractory chronic cough

Refractory chronic cough (RCC) is defined as cough lasting longer than 8 weeks either in the absence of an identifiable underlying cause or that remains resistant to treating any potential underlying causes [1]. Affected patients have a poor quality of life and suffer from fatigue, disturbed sleep, incontinence, frustration, anxiety, and depression [2]. Despite being a debilitating condition, no licensed treatment is available.

Blocking NMDA receptors with memantine in refractory chronic cough patients is poorly tolerated and demonstrates no improvement in coughhttps://bit.ly/3kgx2g1

Impact of guideline awareness on the counseling of patients with acute cough among general practitioners and pharmacy personnel

Objective

To explore the awareness and knowledge of applicable guidelines on acute cough among general practitioners, pharmacists and pharmacy technicians and to compare their recommendation behavior and clinical decision making to the evidence-based recommendation in the applicable guidelines.

Methods

An anonymous online survey was performed among 303 members of an existing panel of healthcare professionals (HCPs). They were presented with a hypothetical case vignette representative of their daily practice and asked for their treatment recommendations. After being shown an excerpt from the applicable guidelines, these questions were repeated.

Results

Forty-six % of participants reported to seek information on cough and respiratory conditions very often or often. Among 12 non-prescription treatments-commonly used over-the-counter-products for acute cough, HCPs most often recommended various plant extract-based products (phytotherapeutic remedies) for the acute cough case, whereas chemically defined options such as ambroxol or N-acetyl-cysteine were recommended less often. Following presentation of the guidelines excerpt, recommendations of the phytotherapeutic remedies decreased moderately whereas that of the guideline-recommended ambroxol more than doubled. Among stated reasons for the recommendation guideline conformity increased from 5% to 35% among the top-3 reasons.

Conclusions

The recommendations for the treatment of acute cough by professionals involved in primary healthcare deviated considerably from the applicable guideline recommendation but changed after presentation of a guidelines excerpt and knowledge thereof. We conclude that dissemination of applicable guideline knowledge is relevant to improve evidence-based healthcare and clinical decision making.

Efficacy of non-sedating H1-receptor antihistamines in adults and adolescents with chronic cough: A systematic review

Background

Nasal symptoms frequently coexist in patients with chronic cough, and non-sedating H1-receptor antihistamines (nsH1RAs) are often prescribed for cough management in several countries. However, recommendations on the use of nsH1RAs vary among chronic cough guidelines. This study aimed to examine the efficacy of nsH1RAs over placebos in adolescents or adults with chronic cough or allergic respiratory conditions that may present as chronic cough.

Methods

Electronic databases were searched for studies published until November 2020. Randomized placebo-controlled trials of nsH1RAs reporting cough endpoints in adolescents or adults with chronic cough or cough-associated allergic respiratory conditions (allergic rhinitis, allergic asthma, or atopic cough) were included.

Results

A total of 10 placebo-controlled trials were identified. Three studies (one study each involving allergic rhinitis, allergic rhinitis with comorbid asthma, and atopic cough) described baseline and post-treatment cough scores, and all reported significant improvements in subjective cough scores; however, the magnitude of improvement was greater in the 2 studies of patients with atopic cough (relative improvement in cough frequency score: −36.6 ± 8.4%) or seasonal allergic rhinitis-associated cough (cough frequency score: −44.0 ± 7.3% and cough intensity score: −65.7 ± 8.3%) than in the 1 study of allergic rhinitis patients with comorbid asthma (−4.0 ± 1.3%). Meanwhile, the other 7 trials found conflicting results but lacked information on the baseline cough score and did not use validated cough measurement tools; thus, their clinical relevance could not be determined.

Conclusion

Despite the widespread use of nsH1RAs in patients with chronic cough, only a few clinical trials examining their benefits on cough outcomes have been conducted. There may be a subgroup of patients, particularly those with seasonal allergic rhinitis-associated cough or atopic cough, whose cough may improve with nsH1RA treatment. However, adequately powered trials with validated cough measurement tools are warranted to confirm the role of nsH1RAs in the management of patients with allergic phenotypes of chronic cough.

Web-based survey to evaluate the prevalence of chronic and subacute cough and patient characteristics in Japan

Background

Cough lasting 3–8 weeks and more than 8 weeks are defined as subacute/prolonged cough and chronic cough, respectively. Japanese chronic cough population has not been well studied. This study aimed to describe the prevalence and characteristics of chronic cough and subacute cough patients in Japan. This study also sought to compare between chronic cough patients who were not greatly satisfied with treatment effectiveness for resolving cough and other chronic cough patients.

Methods

Data from a cross-sectional online 2019 Japan National Health and Wellness Survey and a supplemental chronic cough survey were used to understand respondents’ chronic cough status and their cough-specific characteristics and experience. The prevalence, patient characteristics and cough-specific characteristics were summarised descriptively. Patients who were not greatly satisfied with treatment effectiveness and other chronic cough patients were compared for their characteristics and cough severity.

Results

The point prevalence of chronic cough was 2.89% and 12-month period prevalence was 4.29%. Among all chronic cough patients analysed, the average age was 56 years old, 61.1% were males and 29.4% were current smokers. Patients were most frequently told by a physician that cough was related to allergic rhinitis, asthma and cough variant asthma. Only 44.2% of chronic cough patients had spoken with a physician about their cough, and half of chronic cough patients did not use any medications. Patients who were not greatly satisfied with treatment effectiveness had significantly greater cough severity during past 2 weeks compared with other chronic cough patients (Visual Analogue Scale 45.34 vs 39.63).

Conclusions

This study described the prevalence and patient characteristics information of chronic cough patients in Japan. Furthermore, the study highlighted an unmet need for better diagnosis and treatments for chronic cough patients, especially among patients who were not greatly satisfied with treatment effectiveness and reported significantly worse cough severity.

Effects of Cough Suppression Therapy on Voice Disorder Severity

OBJECTIVES//HYPOTHESIS

To determine changes in voice severity when treating chronic cough refractory to medical treatment with cough suppression therapy (CST) in patients with chronic cough and voice complaints. Chronic cough has been reported to be refractory to medical treatment and frequently co-occurs with voice disorders. The possible effects of CST on self-assessed changes in chronic cough and voice disorders have not been demonstrated.

STUDY DESIGN

Retrospective analysis of the effects of cough suppression therapy (CST) on self-assessed changes in chronic cough and voice disorder severity in patients with both chronic cough and voice disorders.

METHODS

Forty-three adult patients with the primary complaint of chronic refractory cough underwent pre- and post-treatment diagnostic examinations, completed pre- and post-treatment Voice Handicap Index-10 (VHI-10) and Cough Severity Index assessments, and were treated by a licensed speech-language pathologist using CST. Twenty-seven subjects were assigned to the cough (C) group and 16 to the cough-voice (CV) group based on the severity of their VHI-10 scores.

RESULTS

Post-test analysis showed significant improvement in cough severity for both groups and significant improvement in voice severity for the CV group. The VHI-10 scores for the C group did not change significantly. The median number of treatment sessions was 3, with a range of 1-13 sessions. Correlation between changes in severity and number of treatment sessions was not found to be significant at the tested level.

CONCLUSIONS

CST represents a unifying approach for treatment of patients with CRC and comorbid voice disorders. CST offered cross-over effects to the voice when subjects were treated for their primary complaint of chronic cough. This treatment of the primary complaint improves function in systems that share a common pathway.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

Presentation of the Therapy Program for Management of Chronic Cough

PURPOSE

To present a proposal for speech-language pathology rehabilitation called the Therapy Program for Management of Chronic Cough (TMCC) for the treatment of refractory chronic cough.

METHODS

TMCC was developed based on two stages: literature and clinical analysis. The literature analysis stage was carried out through the following procedures: electronic and manual search for articles and books published until June 2019 that included adult participants with chronic cough and intervention with speech-language pathology therapy; selection of sources; analysis of articles and books included; and, preparation of the initial version of the therapy program. The initial version of the therapy program resulting from literature analysis stage was submitted to clinical analysis stage through the following procedures: analysis by three judges; revision of the proposal by the authors; judges' re-analysis; elaboration of the final version called the Therapy Program for Management of Chronic Cough (TMCC).

RESULTS

TMCC synthesizes scientific knowledge and current clinical experience on the behavioral management of refractory chronic cough into a program with three main components, each one with specific objectives and strategies. TMCC consists of four sessions, with weekly frequency and duration between 30-45 minutes per session, executed in hierarchical phases, with specific objectives and strategies per session.

CONCLUSION

TMCC is a program structured to offer global cough rehabilitation. To obtain scientific evidence about its effectiveness is necessary, so that it can be used in clinical practice.

Differential features of chronic cough according to etiology and the simple decision tree for predicting causes

Finding etiology of chronic cough is an essential part of treatment. Although guidelines include many laboratory tests for diagnosis, these are not possible in many primary care centers. We aimed to identify the characteristics and the differences associated with its cause to develop a clinical prediction model. Adult subjects with chronic cough who completed both Korean version of the Leicester Cough Questionnaire (K-LCQ) and COugh Assessment Test (COAT) were enrolled. Clinical characteristics of each etiology were compared using features included in questionnaires. Decision tree models were built to classify the causes. A total of 246 subjects were included for analysis. Subjects with asthma including cough variant asthma (CVA) suffered from more severe cough in physical and psychological domains. Subjects with eosinophilic bronchitis (EB) presented less severe cough in physical domain. Those with gastro-esophageal reflux disease (GERD) displayed less severe cough in all 3 domains. In logistic regression, voice hoarseness was an independent feature of upper airway cough syndrome (UACS), whereas female sex, tiredness, and hypersensitivity to irritants were predictors of asthma/CVA; less hoarseness was a significant feature of EB, and feeling fed-up and hoarseness were less common characteristics of GERD. The decision tree was built to classify the causes and the accuracy was relatively high for both K-LCQ and COAT, except for UACS. Voice hoarseness, degree of tiredness, hypersensitivity to irritants and feeling fed-up are important features in determining the etiologies. The decision tree may further assists classifying the causes of chronic cough.

Prevalence and associated factors of pelvic organ prolapse among women attending gynecologic clinic in referral hospitals of Amhara Regional State, Ethiopia

INTRODUCTION AND HYPOTHESIS

While pelvic organ prolapse is common in clinical observation, there is a lack of evidence regarding its actual proportion and associated factors in the study area. Understanding the prevalence and risk factors could potentially help with prevention. Thus, this study aimed to determine the prevalence and associated factors related to pelvic organ prolapse in the Amhara region, northwest Ethiopia.

METHODS

An institutional-based cross-sectional study was conducted among 424 women, recruited by the systematic random sampling technique. Data were collected in a face-to-face interview using a structured and pre-tested questionnaire to assess the symptoms of pelvic organ prolapse and the socio-demographic, obstetric, gynecologic, medical and surgical characteristics. The stage of prolapse was determined by pelvic examination using the Simplified Pelvic Organ Prolapse Quantification staging system. Descriptive statistics and logistic regression analyses were employed.

RESULTS

The overall prevalence of pelvic organ prolapse (stage I-IV) was found to be 37.6% when determined by pelvic examination and 9.2% as assessed by prolapse symptoms. Age ≥ 40 years [AOR 2.46 (1.320, 5.314)], age at first delivery ≤ 20 years [AOR 4.719 (2.44, 9.11)], carrying heavy objects for ≥ 5 hours a day [AOR 12.724 (4.89, 33.07)], parity ≥ 4 [AOR 3.739 (1.693, 8.208)], prolonged labor [AOR 3.487 (1.699, 7.159)], constipation [AOR 2.835 (1.273, 6.317)] and anemia [AOR 2.22 (1.049, 4.694)] were significantly associated with pelvic organ prolapse.

CONCLUSION

Prevalence of pelvic organ prolapse is high in the area; thus, developing information and education programs on avoiding risk factors is advisable to reduce the problem.

The spectrum, clinical features and diagnosis of chronic cough due to rare causes

Background

Chronic cough has many diverse causes, including common and uncommon causes. There are few comprehensive reports on rare causes of chronic cough. The purpose of this study is to determine the etiological distribution, clinical features, and diagnostic value of special examinations in patients with rare causes of chronic cough.

Methods

A retrospective analysis of patients with chronic cough who underwent medical history taking, full examination, and etiological treatment over a 13-year period was conducted. Causes of chronic cough with a prevalence of less than 3% were defined as rare causes.

Results

A total of 1,554 patients were enrolled, and 39 causes of chronic cough were identified. Among them, 1,055 cases were due to common causes, whereas 235 cases were due to rare causes; the causes involved 7 bodily systems. The top five rare causes were protracted bacterial bronchitis, somatic cough syndrome, diffuse panbronchiolitis, obstructive sleep apnea syndrome (OSAS), and interstitial lung disease, accounting for 67.2% of all rare causes. Among 235 patients with rare causes, causes in 90 (38.3%) patients were detected by chest high-resolution computed tomography (HRCT), in 44 (18.7%) patients by bronchoscopy/nasopharyngoscopy, and in 21 (8.9%) patients by pulmonary spirometry and diffusing capacity testing.

Conclusions

Among the 31 rare causes of chronic cough in this cohort, the top five were protracted bacterial bronchitis, somatic cough syndrome, diffuse panbronchiolitis, OSAS, and interstitial lung disease. Special examinations, such as chest HRCT and bronchoscopy, should be considered after excluding common causes of chronic cough.

Characteristic appearance of the oropharynx in patients with postnasal drip (PND)-induced cough

INTRODUCTION

Post-nasal drip (PND)-induced cough is a common cause of chronic cough. However, there is little known about the characteristic physical findings of this condition.

OBJECTIVES

We investigated views of the pharyngeal wall in patients with PND-induced cough using a handy endoscopic images.

METHODS

The subjects were 135 consecutive patients referred to our hospital with a sensation of something "dripping down the throat" as one of their symptoms. Physical findings for the oropharynx were examined using Wi-Fi endoscope camera. The difference in probability of symptoms in patients with acute cough and those with subacute/chronic cough was assessed using a Bayesian Fisher exact test on a 2 × 2 table.

RESULTS

Among the patients, 105 (78%) complained of cough, 78 (58%) of acute cough, 20 (15%) of subacute cough, and 7 (5%) of chronic cough; and 71 (53%) had coexisting asthma. Using Bayesian inference, a sore or scratchy throat and fever were more common in patients with acute cough than in those with subacute/chronic cough. In endoscopic images of the oropharynx, a reddish curtain sign on the posterior pharyngeal wall behind the palatopharyngeal arch was found in 121 patients (90%).

CONCLUSION

Patients with acute PND-induced cough have a component of acute upper respiratory infection, because of high probability of a sore or scratchy throat and fever as symptom. A reddish curtain sign may be a useful finding for identifying PND-induced cough in these cases.

Sensory Innervation of the Larynx and the Search for Mucosal Mechanoreceptors

Purpose The larynx is a uniquely situated organ, juxtaposed between the gastrointestinal and respiratory tracts, and endures considerable immunological challenges while providing reflexogenic responses via putative mucosal mechanoreceptor afferents. Laryngeal afferents mediate precise monitoring of sensory events by relay to the internal branch of the superior laryngeal nerve (iSLN). Exposure to a variety of stimuli (e.g., mechanical, chemical, thermal) at the mucosa-airway interface has likely evolved a diverse array of specialized sensory afferents for rapid laryngeal control. Accordingly, mucosal mechanoreceptors in demarcated laryngeal territories have been hypothesized as primary sources of sensory input. The purpose of this article is to provide a tutorial on current evidence for laryngeal afferent receptors in mucosa, the role of mechano-gated ion channels within airway epithelia and mechanisms for mechanoreceptors implicated in laryngeal health and disease. Method An overview was conducted on the distribution and identity of iSLN-mediated afferent receptors in the larynx, with specific focus on mechanoreceptors and their functional roles in airway mucosa. Results/Conclusions Laryngeal somatosensation at the cell and molecular level is still largely unexplored. This tutorial consolidates various animal and human researches, with translational emphasis provided for the importance of mucosal mechanoreceptors to normal and abnormal laryngeal function. Information presented in this tutorial has relevance to both clinical and research arenas. Improved understanding of iSLN innervation and corresponding mechanotransduction events will help shed light upon a variety of pathological reflex responses, including persistent cough, dysphonia, and laryngospasm.

Drug-Induced Cough

Since the recognition of angiotensin-converting enzyme inhibitors (ACEIs)-induced cough, drug has been considered as a potential cause of chronic cough. This review presents recent knowledge on drug-induced coughs in patients with chronic cough. The focus is placed on ACEIs, for which there are a multitude of studies documenting their associations with cough. Additional drugs are discussed for which there are reports of cough as a side effect of treatment, and the potential mechanisms of these effects are discussed.

An Evidence-Based Review of Antitussive Herbs Containing Essential Oils in Traditional Persian Medicine

BACKGROUND

Cough is one of the most common medical symptoms for which medical advice is sought. Although cough is a protective reflex responsible for clearing the airways from secretions and foreign bodies, it can be a troublesome symptom that causes discomfort to patients. Due to the increasing interest in herbal remedies in both developed and developing countries, in the current study, we aimed to overview medicinal herbs containing essential oils used as antitussive agents according to Traditional Persian Medicine (TPM) textbooks. We summarized the relevant scientific evidence on their possible pharmacological effects.

METHODS

To collect the evidence for the treatment of cough or "seaal" (cough in ancient books) from TPM sources, five main medicinal Persian manuscripts were studied. The antitussive herbs were listed and their scientific names were identified and authenticated following botanical reference books. ScienceDirect and PubMed online databases were searched for related mechanisms of action of the reported medicinal plants.

RESULTS

Forty-nine herbs containing essential oils have been recommended in TPM for the treatment of cough; 21 of them had at least one known mechanism of action for cough suppression in the scientific literature. According to this review, most of the cited medicinal plants were assessed for either nitric oxide inhibitory or antitussive/expectorant activities.

CONCLUSION

In addition to advantageous effects of antitussive herbs recommended by TPM, the present review highlighted some recent evidence-based data on these promising herbs that could be used as an outline for future research on their medicinal use.

Relationship between cough reflex sensitivity and body mass index in children with chronic cough - a pilot study

Obesity is characterized by chronic, low-grade systemic inflammation. Obesity may also be associated with chronic cough. The aim of this pilot study was to clarify relation of cough reflex sensitivity and body mass index (BMI) in children with chronic cough. Altogether 41 children having symptoms of chronic cough were submitted to cough reflex sensitivity measurement. We assessed the relation of cough reflex sensitivity (CKR) due to BMI. Cough reflex sensitivity was defined as the lowest capsaicin concentration which evoked two (C2) or five (C5) coughs. Capsaicin aerosol in doubling concentrations (from 0.61 to 1250 micromol/l) was inhaled by a single breath method (KoKo DigiDoser; nSpire heath Inc, Louisville, CO, USA), modified by the addition of an inspiratory flow regulator valve (RIFR; nSpire heath Inc, Louisville, CO, USA). BMI was calculated. Pulmonary function was within normal range. Concentrations of capsaicin causing two (C2) and five coughs (C5) were reported. Children (22 boys and 19 girls, mean age 6.8 years) cough reflex sensitivity (median, with the Inter-Quartile Range) for C2 was 19.5 (73.4) micromol/l; for C5 it was 78.1 (605.5) micromol/l. We have noticed statistically significant relation of the cough reflex sensitivity (C5) and body mass index (P<0.0001); however, the effect size was small, R2=0.03. Increase of body mass index in one unit is associated with -34.959 micromol/l decrease of C5. We did not find a statistically significant relation between C2 and BMI (P=0.41). The median value of CKR (C2) in boys is not statistically significantly different than the median value of CKR (C2) in girls (P-value 0.5). The median value of CKR (C5) in boys is not statistically significantly different than the median value of CKR (C5) in girls (P-value 0.5). Increase of body mass index in children suffering from chronic cough relates to decrease of cough reflex sensitivity (C5 value).

Cough hypersensitivity and suppression in COPD

Cough reflex hypersensitivity and impaired cough suppression are features of chronic refractory cough (CRC). Little is known about cough suppression and cough reflex hypersensitivity in cough associated with chronic obstructive pulmonary disease (COPD). This study investigated the ability of patients with COPD to suppress cough during a cough challenge test in comparison to patients with CRC and healthy subjects. This study also investigated whether cough reflex hypersensitivity is associated with chronic cough in COPD.Participants with COPD (n=27) and CRC (n=11) and healthy subjects (n=13) underwent capsaicin challenge tests with and without attempts to self-suppress cough in a randomised order over two visits, 5 days apart. For patients with COPD, the presence of self-reported chronic cough was documented, and objective 24-h cough frequency was measured.Amongst patients with COPD, those with chronic cough (n=16) demonstrated heightened cough reflex sensitivity compared to those without chronic cough (n=11): geometric mean±sd capsaicin dose thresholds for five coughs (C5) 3.36±6.88 µmol·L^-1 versus 44.50±5.90 µmol·L^-1, respectively (p=0.003). Participants with CRC also had heightened cough reflex sensitivity compared to healthy participants: geometric mean±sd C5 3.86±5.13 µmol·L^-1 versus 45.89±3.95 µmol·L^-1, respectively (p<0.001). Participants with COPD were able to suppress capsaicin-evoked cough, regardless of the presence or absence of chronic cough: geometric mean±sd capsaicin dose thresholds for 5 coughs without self-suppression attempts (C5) and with (CS5) were 3.36±6.88 µmol·L^-1 versus 12.80±8.33 µmol·L^-1 (p<0.001) and 44.50±5.90 µmol·L^-1 versus 183.2±6.37 µmol·L^-1 (p=0.006), respectively. This was also the case for healthy participants (C5 versus CS5: 45.89±3.95 µmol·L^-1 versus 254.40±3.78 µmol·L^-1, p=0.033), but not those with CRC, who were unable to suppress capsaicin-evoked cough (C5 versus CS5: 3.86±5.13 µmol·L^-1 versus 3.34±5.04 µmol·L^-1, p=0.922). C5 and CS5 were associated with objective 24-h cough frequency in patients with COPD: ρ= -0.430, p=0.036 and ρ= -0.420, p=0.041, respectively.Patients with COPD-chronic cough and CRC both had heightened cough reflex sensitivity but only patients with CRC were unable to suppress capsaicin-evoked cough. This suggests differing mechanisms of cough between patients with COPD and CRC, and the need for disease-specific approaches to its management.

A Randomized Controlled Trial to Assess the Effect of Lidocaine Administered via Throat Spray and Nebulization in Patients with Refractory Chronic Cough

BACKGROUND

Refractory chronic cough (RCC) is a debilitating condition for which there are no licensed treatments. Lidocaine is a nonselective inhibitor of voltage-gated sodium channels with potential antitussive effects, but randomized placebo-controlled studies evaluating its efficacy in RCC are lacking.

OBJECTIVE

To investigate the efficacy of nebulized lidocaine and lidocaine throat spray versus matched placebos in RCC.

METHODS

This was a randomized, double-blind, double-dummy, placebo-controlled, 3-way crossover study, comparing the effect of single doses of nebulized lidocaine with lidocaine delivered by a throat spray and matched placebo. The primary end point was cough frequency over the 10 hours following treatment. Secondary end points were visual analog scale scores for urge-to-cough and cough severity; an exploratory analysis evaluated hourly cough rates up to 5 hours after treatment.

RESULTS

Twenty-six subjects with RCC were recruited (22 females; mean age, 53.5 ± 12.1 years; FEV₁ %predicted, 105.2 ± 16.8 L; forced vital capacity %predicted, 112.4 ± 18 L). Lidocaine throat spray, but not nebulized lidocaine, significantly reduced 10-hour cough frequency as compared with placebo (throat spray, 22.6 coughs/h; nebulization, 26.9 coughs/h; and placebos, 27.6 coughs/h; P = .04,). Lidocaine throat spray showed the greatest effect on cough compared with placebo in the first hour after administration (31.7 coughs/h vs 74.2 coughs/h; P = .004). Both nebulizer and spray treatments significantly alleviated urge-to-cough and cough severity visual analog scale scores compared with placebo (P < .05). There were no serious adverse events associated with lidocaine therapy.

CONCLUSIONS

Lidocaine throat spray was effective in reducing cough frequency in patients with RCC. Voltage-gated sodium channel inhibitors applied to pharynx have potential as therapies for RCC.

The effect of pain conditioning on experimentally evoked cough: evidence of impaired endogenous inhibitory control mechanisms in refractory chronic cough

The pathophysiology of refractory chronic cough (RCC) is unclear. We hypothesised that endogenous inhibitory control mechanisms, such as those activated by noxious stimuli inducing pain (conditioned pain modulation) may be capable of inhibiting coughing and urge to cough evoked by inhaled capsaicin. Furthermore, these mechanisms may be impaired in patients with RCC.The objective was to investigate the effects of pain on cough and urge to cough in healthy volunteers and RCC patients. Healthy volunteers and RCC patients underwent a randomised, controlled, four-way crossover study comparing the effect of four interventions on capsaicin-evoked coughing and urge to cough. The interventions comprised immersing a hand in 1) noxious cold water; 2) warm water; 3) warm water, but subjects were instructed to voluntarily supress coughing; and 4) no intervention. The co-primary outcomes were numbers of evoked coughs and urge to cough scores.20 healthy volunteers (mean±sd age 50.1±14.2 years, male:female 10:10) and 20 RCC patients (age 60.1±7.9 years, male:female 9:11) participated. Overall, noxious cold water reduced capsaicin-evoked urge-to-cough scores and cough numbers compared with warm water (1.6 (95% CI 1.3-2.0) versus 2.2 (1.8-2.6), p<0.001 and 4.8 (3.7-6.2) coughs versus 7.9 (6.7-9.5) coughs, p<0.001, respectively). Healthy volunteers and RCC patients demonstrated similar reductions in the urge to cough during noxious cold-water immersion, but noxious cold water and voluntary suppression interventions were less effective at reducing capsaicin-evoked cough in RCC patients than in healthy volunteers (p=0.041).Endogenous inhibitory control mechanisms, specifically those activated by pain, can reduce both coughing and the urge to cough. Impairment of endogenous inhibitory control mechanisms may contribute to excessive coughing in RCC.

Prevalence and Characteristics of Chronic Cough in Adults Identified by Administrative Data

CONTEXT

International Classification of Diseases-9/10 codes for chronic cough (CC) do not exist, limiting investigation.

OBJECTIVE

To develop a computerized algorithm to determine CC prevalence and its characteristics.

DESIGN

This observational study using administrative data identified hierarchically patients aged 18 to 85 years with CC from 2013 to 2016. First, a specialist-diagnosed CC group was identified using an internal CC encounter code during an outpatient visit to a pulmonologist, allergist, otolaryngologist, or gastroenterologist. Subsequently, an event-diagnosed CC group was identified based on clinical notes through natural language processing, ICD-9/ICD-10 cough codes, and dispensed antitussives.

MAIN OUTCOME MEASURES

Prevalence of CC and comparison of clinical characteristics between specialist-diagnosed and event-diagnosed CC subgroups.

RESULTS

A total of 50,163 patients with CC of more than 8 weeks were identified. Of these, 11,290 (22.5%) were specialist diagnosed, and 38,873 (77.5%) were event diagnosed. The CC cohort was 57.4 ± 16.5 years of age; 67.6% were female. The overall prevalence was 1.04% (95% confidence interval = 1.03-1.06) in 2016. Prevalence in 2016 was higher in female patients (1.21%) than in male patients (0.81%), higher in patients aged 65 to 85 years (2.2%) than in patients aged 18 to 44 years (0.43%), and higher in Blacks (1.38%) than in Whites (1.21%). Compared with patients with event-diagnosed CC, patients with specialist-diagnosed CC exhibited significantly higher frequencies of laboratory tests and respiratory and nonrespiratory comorbidities and dispensed medication and lower frequency of pneumonia, all-cause and respiratory-cause emergency department visits and hospitalizations, and dispensed antitussives.

CONCLUSIONS

We identified a CC cohort using electronic data in a managed care organization. Prevalences varied by sex, age, and ethnicity. Clinical characteristics varied between specialist-diagnosed and event-diagnosed CC.

Oral corticosteroids for post-infectious cough in adults: study protocol for a double-blind randomized placebo-controlled trial in Swiss family practices (OSPIC trial)

BACKGROUND

Cough is a common reason for patients to visit general practices. So-called post-infectious cough is defined as lasting 3 to 8 weeks after an upper respiratory tract infection. It can be disabling in daily activities, with substantial impact on physical and psychosocial health, leading to impaired quality of life and increased health care costs. Recommendations for the management of post-infectious cough in primary care are scarce and incoherent. A systematic review and meta-analysis of randomized clinical trials (RCT) assessing patient-relevant benefits and potential harms of available treatments identified six eligible RCTs assessing different treatment regimens (i.e. inhaled fluticasone propionate, inhaled budesonide, salbutamol plus ipratropium-bromide, montelukast, nociception-opioid-1-receptor agonist, codeine, gelatine). No RCT found clear patient-relevant benefits and most had an unclear or high risk of bias. Post-infectious cough is thought to be mediated by inflammatory processes that are also present in exacerbations of asthma or chronic obstructive pulmonary diseases for which there is strong evidence that oral corticosteroids provide patient-relevant benefit without relevant harm. We therefore plan to conduct the first RCT evaluating the effectiveness of oral corticosteroids for post-infectious cough.

METHODS

We are conducting a triple-blinded randomized-controlled and multicentred superiority trial in primary health care practices in Switzerland. We will include 204 adult patients who consult their general practitioner (GP) for a cough lasting 3 to 8 weeks following an upper respiratory tract infection. Participants will be randomly allocated to either the 5-day treatment with oral corticosteroids or placebo. The primary outcome is cough-related quality of life assessed by the Leicester Cough Questionnaire score 14 days after randomization. Secondary outcomes include cough-related quality of life at several time points, overall cessation of cough and adverse events.

DISCUSSION

This RCT will provide evidence on whether oral corticosteroids are beneficial and safe in patients with post-infectious cough. Results can have a substantial impact on the well-being and management of these patients in Switzerland and beyond. An evidence-based treatment for this condition may reduce re-consultations with GPs and spending for antitussive drugs, thus possibly having an impact on health care spending.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04232449 . Prospectively registered on 18 January 2020.

Patient-Reported Burden of Chronic Cough in a Managed Care Organization

BACKGROUND

The burden of chronic cough (CC) requires better understanding.

OBJECTIVE

To determine the severity, health status, and health care resource utilization among patients with CC identified by electronic health records on 2 visits separated by ≥1 year.

METHODS

Information on cough-related burden was collected through survey from patients with CC, including validated questionnaires (the cough health status Leicester Cough Questionnaire [LCQ], the cough hypersensitivity Hull Airway Reflux Questionnaire [HARQ], and the Cough Quality of Life Questionnaire [CQLQ]), CC-associated respiratory and gastrointestinal comorbidities, and treatment responses. Spearman correlation coefficients were reported to examine the associations among the LCQ, HARQ, and CQLQ. Patient demographics and patient-reported CC features were compared between males and females, and among ethnic groups using Robust Poisson regression models.

RESULTS

The survey was completed by 565 patients who were 64.8 ± 12.6 years, 75.8% female, and 60.4% white. CC duration was 8.6 ± 10.5 years with an average weekly severity of 5.3 ± 2.3 (maximum 10). The LCQ score was 11.3 ± 3.9 (maximum 21). The HARQ score was 33.3 ± 13.6 (normal ≤13). The CQLQ score was 56.9 ± 17.5 (maximum 112, worse with higher scores). The Spearman rank correlations were high between the LCQ and HARQ (-0.65), the LCQ and CQLQ (-0.80), and the HARQ and CQLQ (0.69). Patients with CC-associated respiratory and gastrointestinal comorbidities generally showed similar results regarding the above questionnaires. Treatment responses were suboptimal. Women compared with men and non-whites compared with whites reported significantly worse cough severity and poorer LCQ, HARQ, and CQLQ scores.

CONCLUSIONS

CC is self-reported as a burdensome condition, particularly in women and non-white minorities, which markedly affects daily living with inadequate response to treatments.

Rhinovirus-16 increases ATP release in A549 cells without concomitant increase in production

Human rhinovirus (RV) is the most common cause of upper respiratory tract infection (URTI) and chronic airway disease exacerbation. Cough is present in 50–80% of URTI cases, accompanied by heightened airway hypersensitivity, yet no effective treatment currently exists for this infectious cough. The mechanism by which RV causes cough and airway hypersensitivity in URTI is still unknown despite recent advances in potential therapies for chronic cough.

The effect of RV-16 infection (MOI 1) on intracellular ATP stores and ATP release in A549 alveolar epithelial cells was measured.

RV-16 infection was found to significantly increase (by 50% from basal at 24 h) followed by decrease (by 50% from basal at 48 and 72 h) intracellular ATP concentrations, while increasing ATP release (from 72 h) independently of secondary stimulation. This effect was mimicked by intercellular adhesion molecule 1 receptor binding alone through ultraviolet-inactivated sham control. In addition, RV-16-infected cells became more sensitive to secondary stimulation with both hypotonic and isotonic solutions, suggestive of a hypersensitive response. These responses were not mediated via increased TRPV4 or pannexin-1 whole-cell expression as determined by Western blotting. Interestingly, the increased ATP release seen was not a result of increased mitochondrial ATP production.

Thus, this is the first report demonstrating that RV-16 infection of airway epithelial cells causes hypersensitivity by increasing ATP release. These finding provide a novel insight into the process by which viruses may cause cough and identify a potential target for treatment of viral and post-viral cough.

Rhinovirus-infected airway epithelial cells (A549) show increased ATP release with and without a secondary stimulation (mechanical or hypotonic), which may account for increased cough sensitivity seen during respiratory viral infectionshttps://bit.ly/3eABEY9

Perspectives on chronic cough in Korea

Chronic cough is a common condition, and generally affects about 3% of Korean adults with a significant influence on quality of life (QoL). Despite continued clinical and academic efforts, there are unmet needs for chronic cough prevention and management in Korea. Epidemiologically, there are two major challenges: an aging population and air pollution. Korea is one of the most rapidly aging countries, and the relative proportion of elderly to younger people is expected to double within the next two decades. Air pollution is a major concern, but there is very limited evidence on the effects of air pollutant on cough in Korean patients. Clinically, upper and lower airway diseases, such as rhinitis/rhinosinusitis and cough variant asthma/eosinophilic bronchitis, are reported to account for about 75% of chronic cough in Korean adults, which formed the basis in formulating clinical practice guidelines. However, further studies are warranted to resolve clinical uncertainty, particularly for the evaluation and treatment of upper airway conditions in chronic cough. The prevalence of gastroesophageal reflux disease (GERD) is increasing, thus its relevance to cough among Koreans may warrant re-evaluation. Infection-associated chronic cough, such as tuberculosis, is another continuing concern. The proportion of chronic refractory or unexplained cough is assumed to be 10–20% among patients visiting referral clinics for chronic cough. This review presents our perspectives on current epidemiological and clinical issues of chronic cough in Korea, and addresses major knowledge gaps and future research priorities.

Cluster analysis in 975 patients with current cough identifies a phenotype with several cough triggers, many background disorders, and low quality of life

BACKGROUND

Recognition of disorder phenotypes may help to estimate prognosis and to guide the clinical management. Current cough management guidelines classify patients according to the duration of the cough episode. However, this classification is not based on phenotype analyses. The present study aimed to identify cough phenotypes by clustering.

METHODS

An email survey among employed, working-age subjects identified 975 patients with current cough. All filled in a comprehensive 80-item questionnaire including the Leicester Cough Questionnaire. Phenotypes were identified utilizing K-means partitional clustering. A subgroup filled in a follow-up questionnaire 12 months later to investigate the possible differences in the prognosis between the phenotypes.

RESULTS

Two clusters were found. The cluster A included 608 patients (62.4% of the population) and the cluster B 367 patients (37.6%). The three most important variables to separate the clusters were the number of the triggers of cough (mean 2.63 (SD 2.22) vs. 6.95 (2.30), respectively, p < 0.001), the number of the cough background disorders (chronic rhinosinusitis, current asthma, gastroesophageal reflux disease, 0.29 (0.50) vs. 1.28 (0.75), respectively, p < 0.001), and the Leicester Cough Questionnaire physical domain (5.33 (0.76) vs. 4.25 (0.84), respectively, p < 0.001). There were significant interrelationships between these three variables (each p < 0.001). Duration of the episode was not among the most important variables to separate the clusters. At 12 months, 27.0% of the patients of the cluster A and 46.1% of the patients of the cluster B suffered from cough that had continued without interruptions from the first survey (p < 0.001).

CONCLUSIONS

Two cough phenotypes could be identified. Cluster A represents phenotype A, which includes the majority of patients and has a tendency to heal by itself. The authors propose that cluster B represents phenotype TBQ (Triggers, Background disorders, Quality of life impairment). Given the poor prognosis of this phenotype, it urges a prompt and comprehensive clinical evaluation regardless of the duration of the cough episode.

Diagnosis and management of chronic cough: similarities and differences between children and adults

Cough is a natural process that protects the airway. Cough can occur spontaneously or voluntarily. It is considered chronic when it is present for longer than 4 weeks in children or 8 weeks in adults. In both, chronic cough causes patient distress and increased healthcare utilization. Etiologies of pediatric chronic cough include asthma, protracted bacterial bronchitis, tracheomalacia, habit cough, and various systemic disorders. While some diagnoses are identifiable by careful history alone, others require testing guided by specific pointers. Flexible fiberoptic bronchoscopy has been an important tool to identify etiologies of chronic cough that were not otherwise apparent. In adults, asthma and bronchitis are well-defined etiologies of chronic cough, but much chronic cough in adults is largely a conundrum.

Reviews of adult chronic cough report that at least 40% of adults with chronic cough have no medical explanation. Gastroesophageal reflux and upper airway cough syndrome (a.k.a. post-nasal drip) have been common diagnoses of chronic cough, but those diagnoses have no support from controlled clinical trials and have been subjected to multiple published critiques. Cough hypersensitivity is considered to be an explanation for chronic cough in adults who have no other confirmed diagnosis. Gabapentin, a neuromodulator, has been associated with a modest effect in adults, as has speech pathology. While habit cough has not generally been a diagnosis in adults, there is evidence for a behavioral component in adults with chronic cough. Treatment for a specific diagnosis provides a better outcome than trials of cough suppression in the absence of a specific diagnosis. More data are needed for chronic cough in adults to examine the hypothesized cough hypersensitivity and behavioral management. This article reviews etiologies and the treatment of chronic cough in children and the conundrum of diagnosing and treating chronic cough in adults.

Recent progress in the management of chronic cough

Chronic cough is a common clinical condition with significant impact on quality of life and for which effective therapy remains an unmet clinical need. Over the past decade, there has been a major shift in how we approach this problem, driven by better appreciation of the clinical manifestation of chronic cough and an improved understanding of the associated neurobiology. "Cough hypersensitivity syndrome" has been proposed as a new diagnostic term for chronic cough, encompassing different phenotypes of the condition. Accumulating evidence suggests that this new concept is clinically relevant. However, while it is gaining widespread endorsement within the allergy and respiratory community, raising its profile in routine clinical practice is a priority. Thus, the present paper reviews recent progress in our understanding and management of chronic cough, with focus on mechanistic and clinical studies. It also provides detail on knowledge gaps and future research directions.

Application of a simple point-of-care test to reduce UK healthcare costs and adverse events in outpatient acute respiratory infections

Background: Acute respiratory infection (ARI) accounts for over two-thirds of total antibiotic prescriptions although most are caused by viruses that do not benefit from antibiotics. Most antibiotics are prescribed in the outpatients setting. Antibiotic overuse leads to antibiotic-related adverse events (AEs), inclusive of secondary infections, resistance, and increased costs. Point-of-care tests (POCT) may reduce unnecessary antibiotics. A cost analysis was performed to assess diagnostic POCT options to identify patients with an ARI that may benefit from antibiotics in a United Kingdom (UK) outpatient setting.Methods: Healthcare savings were estimated using a budget impact analysis based on UK National Institute for Health and Care Excellence (NICE) data and direct costs (antibiotics, AEs, POCTs) derived from published literature. Otitis media, sinusitis, pharyngitis and bronchitis were considered the most common ARIs. Antibiotic-related AE costs were calculated using re-consultation costs for anaphylaxis, Stevens-Johnson syndrome, allergies/diarrhea/nausea, C. difficile infection (CDI). Potential cost-savings from POCTs was assessed by evaluating NICE guideline-referenced POCTs (CRP, FebriDx, Sarasota, FL) as well as a target product profile (TPP).Results: Fifty-percent (7,718,283) of ARI consultations resulted in antibiotics while guideline-based prescribing suggest appropriate antibiotic prescriptions are warranted 9% (1,444,877) of ARI consultations. Direct antibiotic costs for actual ARI consultations associated with antibiotics was £24,003,866 vs. £4,493,568 for guideline-based, "appropriate" antibiotic prescriptions. Antibiotic-related AEs and re-consultations for actual vs. appropriate prescribing totaled £302,496,486 vs. £63,854,269. ARI prescribing plus AE costs totaled £326,729,943 annually without the use of delayed prescribing practices or POCT while the addition of delayed prescribing plus POCT totaled £60,114,564-£78,148,933 depending on the POCT.Conclusions: Adding POCT to outpatient triage of ARI can reduce unnecessary antibiotics and antibiotic-related AEs, resulting in substantial cost savings. Further, near patient diagnostic testing can benefit health systems and patients by avoiding exposure to unnecessary drugs, side effects and antibiotic resistant pathogens.Key points for decision makersMany patients are unnecessarily treated with antibiotics for respiratory infections.Antibiotic misuse leads to unnecessary adverse events, secondary infections, re-consultations, antimicrobial resistance and increased costs.Point-of-care diagnostic tests used to guide antibiotic prescriptions will avoid unnecessary adverse health effects and expenses.

Cough Severity Index in Brazilian Portuguese: Translation and Cross-Cultural Adaptation

OBJECTIVE

To translate and cross-culturally adapt the Cough Severity Index to Brazilian Portuguese.

MATERIAL AND METHODS

This is a study with observational, cross-sectional, and analytical design. The procedure for translation and cross-cultural adaptation followed the recommendations of the Scientific Advisory Committee of the Medical Outcomes Trust and was performed in five stages: translation, synthesis, back translation, committee review, and pretesting. The sample for the pretest consisted of 34 participants with refractory chronic cough, 11 males and 23 females, with an average age of 48 years and 1 month.

RESULTS

The title of the questionnaire, the answer options, and seven of the ten questions were agreed upon by three judges, the remaining three questions were retranslated by a fourth judge. After back-translation and committee review, editing of question five was necessary. The option "never" was more frequently selected for four questions and the option "always" for six questions. There was a significantly higher proportion of other response categories of the instrument compared to the response category "not applicable."

CONCLUSION

This study resulted in the elaboration of a translated and cross-culturally adapted version of the Cough Severity Index in Brazilian Portuguese.