Measuring cough severity: Perspectives from the literature and from patients with chronic cough

Development of an Italian version of the Leicester cough questionnaire and its relationship with other symptom-specific measures for patients with chronic cough

OBJECTIVE

To implement subjective methods for measuring the impact of chronic cough on patients' daily life, including an Italian version of the symptom-specific, health status measure for patients with chronic cough, i.e. the Leicester Cough Questionnaire (LCQ).

METHODS

Sixty-five chronic cough patients attended a tertiary cough clinic on two separate occasions 8 weeks apart. The visual analogue scale for cough severity (VAS), the LCQ and the cough disturbance score (CDS) were administered on both occasions. The LCQ was adapted for Italian conditions following a forward-backward translation procedure. Concurrent validation, internal consistency, repeatability and responsiveness were determined.

RESULTS

The CDS, VAS and LCQ were correlated (r coefficients ranging from 0.69 to 0.94, p < 0.01). The internal consistency for each LCQ domain was high (alpha coefficient range 0.87-0.93), as was the 8-week repeatability of the LCQ in the patients (n = 36, 60 %) who displayed no change in CDS and VAS (intra-class correlation coefficient = 0.86, p < 001) over the same period. Patients who reported an improvement in CDS and VAS after 8 weeks (n = 29) also demonstrated significant improvements in each LCQ domain. The mean difference in LCQ total score before and after improvements was 2.26 (95 % CI: 1.58-4.47).

CONCLUSIONS

The Italian version of the LCQ appears to be just as valid as the other language versions of the questionnaire. In addition, the CDS appears to be a clinically useful, symptom-specific measure of the overall disturbance provoked by cough.

Quality of Life in Adults with Chronic Cough: A Mixed Methods Study Informing the Development of a Quantitative Patient Preference Study

OBJECTIVES

This study aimed to describe quality of life for patients with chronic cough (CC) and identify meaningful attributes that affect patient treatment preferences to inform the design of a quantitative preference study.

METHODS

Eligible patients (≥ 18 years) with a CC (> 8 weeks) participated in qualitative interviews with two defined steps. Step one: concept elicitation and bidding games were used to collect descriptions of patient experiences with CC and identify important CC-related attributes. Step two: attributes were confirmed using concept elicitation and bidding games and prioritized using structured card sort activities. Purposive sampling ensured diversity of patient experiences. Qualitative content analysis was used to analyze participant narratives, and descriptive statistics were used to summarize card sort results. This study follows a fully mixed concurrent dominant status design, with qualitative (dominant) and quantitative components.

RESULTS

A total of 20 participants were interviewed with a mean age of 61.4 years (range 24-79 years). Coughing episodes, described as intense consecutive coughs that made catching breath difficult, were important to most participants (n = 17). Participants emphasized the emotional impact of episodes including feelings of uncertainty, loss of control, self-consciousness, and fear. Severity of CC was most often judged by frequency (n = 11) and intensity (n = 12) of cough. Daily, physical, or social activities were impacted for most participants. Impact on sleep (n = 14) included waking during the night, difficulty falling asleep, and daytime fatigue. Medication-related taste disturbances were an important consideration for what participants were willing to accept in exchange for cough relief.

CONCLUSIONS

This study emphasizes the importance of coughing episodes for adults with CC and provides initial evidence that taste alterations are an important component of patient treatment decisions for CC.

Patient preferences for the treatment of chronic cough: a discrete choice experiment

BACKGROUND

Chronic cough is common, negatively affects quality of life and has limited treatment options. Inhibition of purinergic signalling is a promising therapeutic approach but is associated with taste-related adverse effects. Little is known about treatment preferences from the perspective of patients with chronic cough, such as trade-offs between efficacy and side effect.

METHODS

Patients with chronic cough completed an online discrete choice experiment survey in which they answered a series of questions requiring a choice between two constructed treatment options characterised by varying attribute levels. Selection of cough and taste-related attributes was informed by qualitative interviews and clinical trial data. Logit-based models were used to analyse resulting choice data.

RESULTS

The discrete choice experiment survey was completed by 472 participants with chronic cough. Among study attributes, frequency of intense cough attacks was the most important to participants, followed by taste change, frequency of night-time coughing and frequency of daytime coughing. To accept the least preferred taste disturbance of a bitter, metallic, chalky or oily taste change, participants required either: (1) elimination of night-time cough along with a slight reduction in daytime cough; (2) elimination of daytime cough along with a pronounced reduction in night-time or (3) reduction in intense cough attacks from 7 to 2 times per week. Two distinct preference patterns were identified, each placing different importance on efficacy versus side effect trade-offs.

CONCLUSIONS

Participants with chronic cough were willing to accept some taste disturbances in exchange for improved efficacy of chronic cough treatments. Knowledge of patient preferences can facilitate shared decision-making.

Patient Global Impression of Severity Scale in Chronic Cough: Validation and Formulation of Symptom Severity Categories

BACKGROUND

The Patient Global Impression of Severity (PGI-S) scale is a self-reported, single-item categorical scale that is increasingly used when assessing chronic cough (CC).

OBJECTIVE

This study aimed to establish validity, repeatability, and responsiveness of the PGI-S scale in CC and use the scale to define discrete categories of severity when measured with other commonly used patient-reported outcome (PRO) tools.

METHODS

Consecutive patients with CC completed the PGI-S scale, cough severity and urge to cough visual analog scales (VAS), and cough-specific health status Leicester Cough Questionnaire (LCQ) at a clinic visit. Validity, repeatability, and responsiveness were assessed, and threshold scores for PRO severity categories determined.

RESULTS

A total of 482 participants completed the assessments; the median (interquartile range [IQR]) age was 57 (46-67) years, 71% were female, and the median (IQR) duration of cough was 48 (24-120) months. They reported a median (IQR) PGI-S score of 3 (3-4; moderate severity), cough severity VAS of 57 (31-75) mm, urge to cough VAS of 62 (40-81) mm, and LCQ of 11.5 (8.7-14.4). There were strong associations between PGI-S scores and cough severity VAS (ρ = 0.81), urge to cough VAS (ρ = 0.73), and LCQ (ρ = -0.73) (all P < .001). Repeatability of the PGI-S scale was high (n = 77); the intraclass correlation coefficient (95% confidence interval) was 0.85 (0.77-0.91) (P < .001). The PGI-S scale was responsive in participants with a treatment response (P < .001). The suggested PRO thresholds to define severe cough are ≥61 mm (cough severity VAS), ≥71 mm (urge to cough VAS), and ≤10 (LCQ).

CONCLUSION

The PGI-S scale is a simple and valid tool that characterizes cough severity and is repeatable and responsive in CC. The proposed categorical severity thresholds for VAS and LCQ can provide intuitive meaning for patients and clinicians.

Perspectives of Patients With Chronic Respiratory Diseases and Medical Professionals on Pulmonary Rehabilitation in Pune, India: Qualitative Analysis

BACKGROUND

Chronic respiratory diseases (CRDs) contribute significantly to morbidity and mortality worldwide and in India. Access to nonpharmacological options, such as pulmonary rehabilitation (PR), are, however, limited. Given the difference between need and availability, exploring PR, specifically remotely delivered PR, in a resource-poor setting, will help inform future work.

OBJECTIVE

This study explored the perceptions, experiences, needs, and challenges of patients with CRDs and the potential of and the need for PR from the perspective of patients as well as medical professionals involved in the referral (doctors) and delivery (physiotherapists) of PR.

METHODS

In-depth qualitative semistructured interviews were conducted among 20 individuals diagnosed with CRDs and 9 medical professionals. An inductive thematic analysis approach was used as we sought to identify the meanings shared both within and across the 2 participant groups.

RESULTS

The 20 patients considered lifestyle choices (smoking and drinking), a lack of physical activity, mental stress, and heredity as the triggering factors for their CRDs. All of them equated the disease with breathlessness and a lack of physical strength, consulting multiple doctors about their physical symptoms. The most commonly cited treatment choice was an inhaler. Most of them believed that yoga and exercise are good self-management strategies, and some were performing yoga postures and breathing exercises, as advised by friends or family members or learned from a televised program or YouTube videos. None of them identified with the term "pulmonary rehabilitation," but many were aware of the exercise component and its benefits. Despite being naive to smartphone technology or having difficulty in reading, most of them were enthusiastic about enrolling in an application-based remotely delivered digital PR program. The 9 medical professionals were, however, reluctant to depend on a PR program delivered entirely online. They recommended that patients with CRDs be supported by their family to use technology, with some time spent with a medical professional during the program.

CONCLUSIONS

Patients with CRDs in India currently manage their disease with nonguided strategies but are eager to improve and would benefit from a guided PR program to feel better. A home-based PR program, with delivery facilitated by digital solutions, would be welcomed by patients and health care professionals involved in their care, as it would reduce the need for travel, specialist equipment, and setup. However, low digital literacy, low resource availability, and a lack of expertise are of concern to health care professionals. For India, including yoga could be a way of making PR "culturally congruent" and more successful. The digital PR intervention should be flexible to individual patient needs and should be complemented with physical sessions and a feedback mechanism for both practitioners as well as patients for better uptake and adherence.

The Efficacy of Superior Laryngeal Nerve Block for Neurogenic Cough: A Placebo-Controlled Trial

OBJECTIVES

Chronic cough is a common and debilitating problem. The objective of this study is to assess the efficacy and safety of superior laryngeal nerve (SLN) block for neurogenic cough through a placebo-controlled, prospective trial.

METHODS

Patients were recruited in an outpatient tertiary care center. Inclusion criteria included a history consistent with neurogenic cough and age ≥ 18. Exclusion criteria included patients with untreated other etiologies of chronic cough (i.e., uncontrolled reflux) and current neuromodulating medication use. Patients were randomized into the treatment (1-2 mL of a 1:1 triamcinolone 40 mg: 1% lidocaine with 1:200,000 epinephrines) or placebo (saline) group and received two unilateral injections at approximately 2-week intervals. Outcomes were measured primarily by the Leicester Cough Questionnaire (LCQ) and a patient symptom log including a visual analog scale of cough severity.

RESULTS

17 patients completed the study, including 10 in the treatment group and seven in the placebo group. Eight (80%) patients in the treatment group reported improvement with at least one of the injections, whereas only 1 (14.3%) patient reported improvement in the placebo group (p < 0.0001). Average total LCQ scores increased in the treatment group from 10.09 to 13.15 (p = 0.03), with the most change occurring in the social domain. There was no statistically significant change in LCQ scores for the placebo group. There were no serious adverse events.

CONCLUSION

An SLN block is a safe and efficacious procedure for the treatment of neurogenic cough. Further studies are needed to optimize treatment protocol and assess long-term follow-up of patient outcomes.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:3068-3074, 2023.

Burden of chronic cough in the UK: results from the 2018 National Health and Wellness Survey

Background

Chronic cough, defined as daily cough for at least 8 weeks, negatively affects quality of life and work productivity and increases healthcare resource utilisation. We aimed to determine the prevalence and burden of chronic cough in the UK.

Methods

Study participants were general population respondents to the 2018 UK National Health and Wellness Survey (NHWS). Respondents completed survey questions relating to health, quality of life, work productivity and activity impairment, and use of healthcare resources. Prevalence estimates were projected to the UK population using post-stratification sampling weights to adjust for sampling bias. The population with chronic cough was matched 1:3 with a group without chronic cough, using propensity score matchingon age, sex and the modified Charlson Comorbidity Index.

Results

Of 15 000 NHWS respondents, 715 reported chronic cough in the previous 12 months and 918 during their lifetime. Weighted to the UK adult population, the 12-month prevalence of chronic cough was 4.9% and lifetime prevalence was 6.2%. Prevalence of chronic cough was higher among older respondents and those with smoking histories. Chronic cough respondents experienced higher rates of severe anxiety and depression in the past 2 weeks than matched controls. Poor sleep quality and loss of work productivity were also observed. More chronic cough respondents visited a healthcare provider in the past 6 months than respondents without chronic cough with a mean of 5.8 and 3.7 visits per respondent, respectively.

Conclusion

Adults with chronic cough report lower quality of life, reduced work productivity and greater healthcare resource utilisation than matched controls without chronic cough.

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.

[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.

The "vicious circle" of chronic cough: the patient experience - qualitative synthesis

Aim

The aim of this study was to systematically search and synthesise findings from peer-reviewed qualitative studies describing the experiences of those living with chronic cough.

Methods

A systematic search was conducted to identify all studies that used qualitative methodology to report on the experiences of adults living with chronic cough. A thematic synthesis of the first-hand narratives was undertaken. Key themes in relation to personal perspectives and experiences of living with chronic cough were identified and grouped into analytical themes.

Results

Six studies met the inclusion criteria. The thematic synthesis generated three analytical themes: 1) "It's just a cough"; 2) "Constant cough and constant worry"; and 3) "No light at the end of the tunnel", highlighting the biopsychosocial nature of chronic cough. The synthesis highlights chronic cough as a heterogeneous experience that may appear idiosyncratic, completely consuming the lives of those living with it.

Conclusion

This is to our knowledge the first qualitative synthesis reporting on the perceptions and experiences of adults living with chronic cough. Our review draws attention to the paucity of literature that utilises qualitative methodology to explore the experience of living with chronic cough. We highlight the missing voice of people living with chronic cough in the contemporary literature. There is now a requirement for research exploring the narratives of those living with chronic cough, to gain an understanding of the condition beyond simple quantification.

Change over time and agreement between clinical markers of disease resolution in dogs with aspiration-induced lung injury

BACKGROUND

There is a lack of consensus regarding which markers of disease resolution to prioritise when assessing treatment response in client-owned dogs with aspiration-induced lung injury. This study describes the change over time and the agreement between the clinical markers used to determine disease resolution.

METHODS

Physical examination (PE), owner-reported clinical signs (CS-O), thoracic radiographs (TXR) scores and C-reactive protein (CRP) concentrations were determined at enrolment, after 24, 48 and 72 hours, and after 7, 14 and 28 days.

RESULTS

PE scores were significantly improved at 48 hours, while CRP initially increased (24 hours) and then decreased (48 hours). PE, CS-O and CRP significantly improved earlier (7 days) than TXR (14 days). The median number of days to marker normalisation was 7, 9 and 14 for PE, CRP and CS-O, respectively. Marker agreement was excellent/very good at enrolment and fair/poor during disease recovery.

LIMITATIONS

Analysis did not control for differences aetiology of aspiration or the lack of standardisation in treatment approach.

CONCLUSIONS

PE was the earliest and most consistent marker indicating disease resolution. Serial CRP monitoring (72 hours) may provide an objective marker of early treatment response. Alongside PE normalisation, improvement in CS-O, CRP and TRX may assist in determining disease resolution and guide treatments, including limiting antibiotic exposure in dogs with aspiration-induced lung injury.

Chronic cough-the limitation and advances in assessment techniques

Accurate and consistent assessments of cough are essential to advance the understanding of the mechanisms of cough and individualised the management of patients. Considerable progress has been made in this work. Here we reviewed the currently available tools for subjectively and objectively measuring both cough sensitivity and severity. We also provided some opinions on the new techniques and future directions. The simple and practical Visual Analogue Scale (VAS), the Leicester Cough Questionnaire (LCQ), and the Cough Specific Quality of Life Questionnaire (CQLQ) are the most widely used self-reported questionnaires for evaluating and quantifying cough severity. The Hull Airway Reflux Questionnaire (HARQ) is a tool to elucidate the constellation of symptoms underlying the diagnosis of chronic cough. Chemical excitation tests are widely used to explore the pathophysiological mechanisms of the cough reflex, such as capsaicin, citric acid and adenosine triphosphate (ATP) challenge test. Cough frequency is an ideal primary endpoint for clinical research, but the application of cough counters has been limited in clinical practice by the high cost and reliance on aural validation. The ongoing development of cough detection technology for smartphone apps and wearable devices will hopefully simplify cough counting, thus transitioning it from niche research to a widely available clinical application.

Cough suppression and HRQoL in adult people with cystic fibrosis: an unexplored correlation

BACKGROUND

Cough suppression assessed by embarrassment about coughing has been shown in adolescents with cystic fibrosis (CF) and negatively affects health-related quality of life (HRQoL) and clinical indicators of disease severity in adolescent females. However, whether cough suppression exists in adults has been studied as little as its effects on clinical and psychological outcomes beyond adolescence.

METHODS

Seventy-one subjects completed the self-reported 'Cystic Fibrosis Questionnaire-Revised (CFQ-R + 14)' and a self-report questionnaire about cough suppression, health-related perspectives, and therapy adherence. The status of CF disease was quantified in terms of the percentage of predicted forced expiratory volume in one second (ppFEV₁), body mass index (BMI), Pseudomonas aeruginosa, pancreatic status, and CF-related diabetes (CFRD). Additional demographic data for sex, age, graduation, employment, and marital status were assessed.

RESULTS

CS exists in adult CF and is associated with impaired HRQoL but not the overall CF disease status regarding BMI, ppFEV₁, or health-related perspectives. Despite a higher prevalence of cough suppression in women, no effect of sex regarding either outcome measure was observed.

CONCLUSION

The results of this study suggest that mental health indicators have an impact on cough suppression.

The COVID-19 pandemic as a catalyst for innovation: a regulatory framework to assess fit-for-purpose innovative approaches in clinical research

The COVID-19 pandemic has had a devastating impact on individuals and multiple aspects of our society including healthcare and clinical research. The silver lining is that the pandemic also served as a catalyst for wider adoption of innovative approaches in clinical research, notably the use of mobile or remote services, and digital technologies. Regulators, clinical study investigators, clinical study participants, sponsors, and other stakeholders collaborated to adopt measures that ensured safe participation in clinical studies whilst maintaining study integrity. In this article, we propose a regulatory framework for assessing fit-for-purpose innovative approaches in clinical research based on Roche/Genentech’s experience during the COVID-19 pandemic with the aim to inform and encourage broader implementation of patient-centric and sustainable innovation in clinical research. Our goal is to contribute to ongoing discussions on introducing innovative approaches in clinical trials and eventually the development of globally harmonised guidelines.

Improvements in Objective and Subjective Measures of Chronic Cough with Gefapixant: A Pooled Phase 3 Efficacy Analysis of Predefined Subgroups

Introduction

In phase 3 trials (COUGH-1/COUGH-2), gefapixant 45 mg twice daily significantly reduced 24-h cough frequency vs placebo in refractory or unexplained chronic cough (RCC or UCC).

Methods

Here, the efficacy of gefapixant 45 mg vs placebo was evaluated across COUGH-1/COUGH-2 in predefined subgroups based on sex, region, age, cough duration, cough severity, cough frequency, and diagnosis (RCC, UCC). Awake cough frequency reductions at Week 12 and LCQ response rates (i.e., ≥ 1.3-point improvement) at Week 24 were assessed.

Results

Among 1360 participants analyzed, gefapixant 45 mg resulted in consistent awake cough frequency reductions overall and across predefined subgroups at Week 12. Gefapixant also resulted in improved LCQ scores across subgroups at Week 24; ≥ 70% of participants in each subgroup treated with gefapixant 45 mg had an LCQ response.

Conclusion

These data suggest gefapixant 45 mg provides consistent objective and subjective efficacy across subgroups of individuals with RCC or UCC.

A new method for objectively evaluating nocturnal cough in adults

BACKGROUND

For the management of cough diseases in adults, an objective method of evaluating nocturnal cough is required.

METHODS

In Study 1, a cough monitoring system was evaluated using 25 adult volunteers. In Study 2, the cough monitoring system was validated using 20 samples from 10 adult patients with cough diseases obtained overnight. In hospitalized patients, our original cough monitoring system with a microphone and accelerometer was used. At the same time, coughs were recorded using a video camera with digital sound recording. The number of coughs in each 8-h video-audio recording was counted manually by three trained observers. All cough data were printed out, and the basal number of cough events, using both the printed-out data and video-audio recordings, were then calculated by three observers.

RESULTS

In Study 1, the cough monitoring system demonstrated good agreement with the number of coughs counted by examiners (sensitivity 99.2%, specificity 98.9%). In Study 2, there was significant agreement in the counts of natural coughs between our system and the video-audio method (p < 0.0001) and between our system and the basal cough events (p < 0.0001).

CONCLUSIONS

Our method demonstrated excellent agreement with the video-audio recording method in adults and is considered extremely useful for the objective monitoring of overnight cough in adult patients with cough diseases.

A double-blind randomised placebo-controlled trial investigating the effects of lesogaberan on the objective cough frequency and capsaicin evoked coughs in patients with refractory chronic cough

Objective

Baclofen is a centrally acting γ-aminobutyric acid type B (GABA_B) receptor agonist which reduces gastro-oesophageal reflux and suppresses the cough reflex; however, central nervous system side-effects limit its use. Lesogaberan is a novel peripherally acting GABA_B agonist, but its effects on refractory chronic cough are unknown.

Design

We performed a single-centre, placebo-controlled, double-blind randomised crossover study in patients with chronic cough, refractory to the treatment of underlying conditions. Patients were randomised to treatment with lesogaberan 120 mg modified release twice daily or matched placebo for 2 weeks and then crossed over to the alternative therapy after a 2-week washout. The primary end-point was 24-h cough frequency measured with an acoustic monitoring system. In addition, cough responses to capsaicin were measured, and gastro-oesophageal reflux assessed by 24-h pH/impedance at screening.

Results

22 patients were randomised to receive lesogaberan/placebo or placebo/lesogaberan (female (73%); mean±sd age 63.7±7.2 years; median (interquartile range) cough duration 10.5 (5.8–17.0) years; mean (95% CI) 45 (29–67) reflux events in 24 h; two patients had abnormal oesophageal acid exposure times). Although lesogaberan reduced cough counts by 26% over placebo, this did not reach statistical significance (p=0.12). However, lesogaberan did significantly improve cough responses to capsaicin (p=0.04) and the number of cough bouts (p=0.04) compared with placebo. Lesogaberan was well tolerated in this study.

Conclusions

Lesogaberan improved cough hypersensitivity and the number of bouts of coughing, but not coughs per hour. This implies a possible role for peripheral GABA_B receptors in refractory chronic cough.

Lesogaberan, a peripherally acting GABA_B agonist, does not reduce 24-h cough frequency in patients with chronic cough despite significantly reducing capsaicin-induced coughinghttps://bit.ly/3uGyPQL

Assessing cough symptom severity in refractory or unexplained chronic cough: findings from patient focus groups and an international expert panel

Background

Cough symptom severity represents an important subjective end-point to assess the impact of therapies for patients with refractory or unexplained chronic cough (RCC/UCC). As existing instruments assessing the severity of cough are neither widely available nor tested for measurement properties, we aim to develop a new patient-reported outcome measure addressing cough severity.

Objective

The aim of this study was to establish items and domains that would inform development of a new cough severity instrument.

Methods

Three focus groups involving 16 adult patients with RCC/UCC provided data that we analysed using directed content analysis. Discussions led to consensus among an international panel of 15 experts on candidate items and domains to assess cough severity.

Results

The patient focus group provided 48 unique items arranged under broad domains of urge-to-cough sensations and cough symptom. Feedback from expert panel members confirmed the appropriateness of items and domains, and provided an additional subdomain related to cough triggers. The final conceptual framework comprised 51 items in the following domains: urge-to-cough sensations (subdomains: frequency and intensity) and cough symptom (subdomains: triggers, control, frequency, fit/bout duration, intensity, quality and associated features/sequelae).

Conclusions

Consensus findings from patients and international experts established domains of urge-to-cough and cough symptom with associated subdomains and relevant items. The results support item generation and content validity for a novel patient-reported outcome measure for use in health research and clinical practice.

The urge-to-cough (subdomains: frequency and intensity) and cough symptom (subdomains: triggers, control, frequency, fit/bout duration, intensity, quality, and associated features/sequelae) represent domains to assess cough severity in RCC/UCChttps://bit.ly/3fI6qkC

Nebulized fentanyl for respiratory symptoms in patients with COVID-19 (ventanyl trial)

Patients with coronavirus disease (COVID-19) commonly experience distressing and challenging respiratory symptoms. Interventions such as oxygen therapy, oral opiates, and traditional nebulizers like ipratropium bromide and salbutamol are variable in their efficacy, and therapy responses in patients are difficult to predict. The purpose of this study is to investigate the efficacy of nebulized fentanyl citrate on dyspnea, cough, and throat pain in patients with COVID-19 and evaluate the safety with any potential adverse events.In COVID-19, about 59% of patients will exhibit cough, 35% generalized body ache and sore throat, and 31% dyspnea. Some methods such as nebulized lidocaine, magnesium sulfate, and systemic opioids have been used to manage the respiratory symptoms. It has been previously shown that fentanyl nebulizer has beneficial effect in improving shortness of breath in patients with chronic obstructive pulmonary disease. The proposed theory behind that was that fentanyl decreased the rate of spontaneous respiratory rate, diminished the brain stem chemoreceptor response to hypoxia and hypercarbia, in addition to exhibiting a modulating effect on the brain stem. Therefore, we hypothesize that nebulized fentanyl has superior effect in improving shortness of breath and relieving cough compared to normal saline, in addition to its advantageous throat pain relief, while exhibiting fewer side effects in patients with COVID 19 infection. Therefore, this phase-III, randomized, comparative, parallel assignment, single-blinded clinical trial aims at assessing the efficacy and safety of nebulized fentanyl to suppress cough, improve breathlessness, and relieve throat pain in patients with COVID-19.

Leicester Cough Questionnaire validation and clinically important thresholds for change in refractory or unexplained chronic cough

INTRODUCTION

The Leicester Cough Questionnaire (LCQ), a cough-specific quality-of-life measure, evaluates the impact of cough across physical, psychological, and social domains in patients with chronic cough (CC). This study assessed the psychometric properties of the LCQ.

METHODS

Data from a phase IIb, randomized controlled trial of the P2X3-receptor antagonist gefapixant were analyzed (NCT02612610). Subjective [Cough Severity Diary, cough severity visual analogue scale, and patient global impression of change (PGIC)] and objective (awake and 24-h cough frequency) data were used to validate the LCQ for use in patients with refractory or unexplained CC (RCC and UCC, respectively). Psychometric analyses included confirmatory factor analyses, internal consistency and test-retest reliability, validity, responsiveness, and estimated within-patient thresholds for clinically meaningful change.

RESULTS

Model-fit values for the proposed three-factor LCQ domains and most individual items were acceptable. Analyses suggest that a mean improvement ranging from 1.3 to 2.3 points for the LCQ total and ⩾0.8, ⩾0.9, and ⩾0.8 points for physical, psychological, and social domain scores, respectively, had the best sensitivity and/or specificity for predicting patient ratings of improvement on the PGIC.

CONCLUSIONS

The LCQ is a valid and reliable measure to evaluate cough-specific quality of life and is a fit-for-purpose measure for use in patients with RCC or UCC. Although a single threshold for defining clinically meaningful change depends on the context of use, the results can help guide both treatment decisions and drug development. Therefore, clinicians may consider a ⩾1.3-point increase in the LCQ total score as clinically meaningful.

Validation of a visual analog scale for assessing cough severity in patients with chronic cough

Introduction:

Patients with chronic cough experience considerable burden. The cough severity visual analog scale (VAS) records patients’ assessment of cough severity on a 100-mm linear scale ranging from “no cough” (0 mm) to “worst cough” (100 mm). Although cough severity scales are widely used in clinical practice and research, their use in patients with refractory or unexplained chronic cough has not been formally validated.

Methods:

This analysis includes data from a phase 2b randomized controlled trial of the P2X3-receptor antagonist gefapixant for treatment of refractory or unexplained chronic cough (NCT02612610). Cough severity VAS scores were assessed at baseline and Weeks 4, 8, and 12. The cough severity VAS was validated using several outcomes, including the Cough Severity Diary (CSD), Leicester Cough Questionnaire (LCQ), patient global impression of change (PGIC) scale, and objective cough frequency. Validation metrics included test–retest reliability, convergent and known-groups validity, responsiveness, and score interpretation (i.e., clinically meaningful change threshold).

Results:

The analysis included 253 patients (median age, 61.0 years; females, 76%). Test–retest reliability of the cough severity VAS was moderate (intraclass correlation coefficient, 0.51). The cough severity VAS had acceptable convergent validity with other related measures (Pearson r of 0.53 and -0.41 for CSD and LCQ total scores, respectively; p < 0.0001 for each). Known-groups validity was supported by significant differences in mean cough severity VAS scores across severity groups defined using CSD, LCQ, and cough frequency tertiles. A large effect size was observed in patients with the greatest improvements in PGIC (Cohen d = -1.8). A ⩾ 30-mm reduction in the cough severity VAS was estimated as a clinically meaningful change threshold for clinical trials in chronic cough.

Conclusions:

The cough severity VAS is a valid and responsive measure. A cough severity VAS reduction of ⩾ 30 mm can discriminate clinically meaningful changes in chronic cough severity in clinical studies.

Cough symptom severity in patients with refractory or unexplained chronic cough: a systematic survey and conceptual framework

BACKGROUND

Cough severity represents an important subjective endpoint in assessing the effectiveness of therapies for patients with chronic cough. Although cough-specific quality of life questionnaires exist, a widely available cough severity instrument with established measurement properties remains unavailable.

AIMS

To identify and summarise the results of studies reporting on the experience of patients with chronic cough and, in the process, develop a conceptual framework to inform development of a patient-reported outcome measurement (PROM) addressing cough severity.

RESULTS

We identified 61 eligible studies reporting on patient experience with chronic cough. Studies provided 82 potential items, of which 43 proved unique and relevant to cough severity. The urge-to-cough sensation and the cough symptom itself represented broad domains of cough severity. Two subdomains under urge-to-cough included frequency (1 item) and intensity (1 item). Five subdomains under cough symptoms included control (2 items), frequency (6 items), bout duration (1 item), intensity (8 items), and associated features/sequelae (24 items).

CONCLUSIONS

Our systematic survey and conceptual framework identified items and domains of cough severity in patients with refractory or unexplained chronic cough. The results support item generation and content validity for a PROM assessing cough severity.

[Perceptions of family doctors, pulmonologists and allergists on the approach to patients with chronic cough. Results of an anonymous survey]

OBJECTIVE

To understand the perception of family doctors, pulmonologists and allergists about the current approach to chronic cough and its impact on patients' quality of life.

MATERIAL AND METHODS

Cross-sectional and anonymous survey disseminated through the scientific societies SEAIC, SEMERGEN, semFYC, SEMG and SEPAR. The participants were 620 family doctors, 92 pulmonologists and 62 allergists. A descriptive analysis of the answers was conducted. Response percentages, medians and interquartile intervals were presented. The differences in the percentages between specialties were evaluated with the chi-square.

RESULTS

Only half of the respondents chose a duration greater than 8 weeks as a criterion for diagnosing chronic cough, and less than half considered refractory/unexplained chronic cough a disease in itself. Family doctors perceived that chronic cough had less impact on patients than did pulmonologists or allergists. After a diagnosis of refractory/unexplained chronic cough, all 3specialties considered the most common approach to be to initiate treatment and to do the follow-up of the patient themselves. Most stated that they had no protocols for managing chronic cough, and more than 90% considered these to be necessary.

CONCLUSIONS

The management of patients with chronic cough by family doctors, pulmonologists or allergists seems to be heterogeneous. There is a need for protocols that standardise diagnosis, referral and treatment criteria to optimise patients' management and reduce the impact of chronic cough.

Azithromycin for the Treatment of Chronic Cough in Idiopathic Pulmonary Fibrosis: A Randomized Controlled Cross-over Trial

RATIONALE

Patients with idiopathic pulmonary fibrosis (IPF) frequently suffer from difficult to treat chronic cough, which substantially affects their quality of life. Azithromycin has been demonstrated to relieve chronic cough in some populations, however this has not been investigated in IPF.

OBJECTIVES

To determine the safety and efficacy of azithromycin for the treatment of chronic cough in patients with IPF.

METHODS

In a double-blind randomized controlled cross-over trial, patients with IPF underwent two 12-week intervention periods (azithromycin 500mg or placebo 3 times per week). The primary outcome was change in cough-related quality of life measured by the Leicester cough questionnaire (LCQ). Secondary outcomes included cough severity measured using Visual Analog Scale (VAS), health-related quality of life assessed by the St. George's Respiratory Questionnaire (SGRQ), and objective cough frequency using audiovisual readings from 24h respiratory polygraphy.

RESULTS

25 patients were randomized (23 men, 2 women), 20 patients completed the study. Mean (standard deviation, SD) age was 67 (8) years, mean (SD) forced vital capacity (FVC) was 65 (16) %-predicted, and diffusion capacity (DLCO) 43 (16) %-predicted. Mean (SD) baseline LCQ was 11.7 (3.7) and 11.3 (3.3) for the azithromycin and the placebo period, respectively, and the corresponding mean (SD) cough VAS 5.6 (2.3) and 5.8 (2.1). There was no significant change in LCQ and VAS with azithromycin or placebo. Similarly, there was no significant difference in change in polygraphy measured cough frequency between the azithromycin and placebo periods. Gastrointestinal adverse effects were more frequent with azithromycin than with placebo (diarrhea 43% vs 5%, p=0.03).

CONCLUSIONS

This randomized controlled trial does not support the use of low dose azithromycin for chronic cough in patients with IPF. Clinical trial registered with ClinicalTrials.gov (NCT02173145).

The Multidimensional Cough Index: A Practical Scale to Measure Cough and Sputum

BACKGROUND

There currently is a lack of easy-to-use instruments with which to assess cough. The aim of the present study was to develop a scale for measuring the characteristics of cough and sputum.

METHODS

The authors developed a scale for assessing cough, including aspects such as intensity, frequency, physical impact, psychosocial impacts and sputum characteristics. The first four components were scored using a Cough Index, with a range of 0 to 20. Sputum information included volume, appearance, and hemoptysis. The scale was administered to 105 patients and re-administered to 51 about two weeks later. The patients also reported cough frequency and intensity using a 100-mm visual analogue scale (VAS) and answered the Leicester Cough Questionnaire (LCQ). Additionally, 12 patients with acute exacerbation (AE) of chronic airways disease were interviewed upon admission to and discharge from the hospital.

RESULTS

Analysis identified only one factor for the Cough Index, and Cronbach's alpha value was 0.819. Cough Index was significantly correlated with VAS_frequency (r = 0.651, p < 0.0001), VAS_intensity (r = 0.543, p<0.0001), and LCQ (r = -0.824, p < 0.0001). The intraclass correlation coefficient of test-retest scores was 0.779. The median Cough Index significantly decreased after AE treatment, as did the number of patients reporting increased sputum production and greenish and dark sputum. A Cough Index ≥ 4 distinguished respiratory patients from healthy subjects, with a sensitivity of 80% and a specificity of 85%.

CONCLUSION

The Multidimensional Cough Index condenses complex aspects related to cough and sputum production into a single instrument, with satisfactory validation.

Gender difference in the association between cough severity and quality of life among patients with postinfectious cough

Background

Despite close link exists between cough severity and quality of life (QoL), whether gender difference is implied in the effect of cough on QoL has not been studied yet. This study primarily aims to investigate whether the association between cough severity and QoL is modified by gender in patients with postinfectious cough.

Methods

Secondary analyses were performed in 180 participants with postinfectious cough in a multisite randomized controlled trial. Baseline demographics, clinical characteristics and score of cough specific quality of life questionnaire (CQLQ) were collected. Linear regression analyses were conducted to examine gender difference in CQLQ score and the association between cough severity and CQLQ score.

Results

Difference between women and men was not significant in CQLQ total score in the unadjusted analysis (P = 0.077). Women had a 2.20-point higher CQLQ total score than men (95% confidence interval (CI) 0.11–4.30; P = 0.039), after adjusting for age, cough duration, cough severity, and clinical center. Gender significantly modified the association between cough severity and CQLQ total score (coefficient 1.80, 95% CI 0.29–3.30; P = 0.020), after adjusting for age, cough duration, and study center. An increase of 1-point in cough severity was associated with a 2.55-point (95% CI 1.16–3.95) increase in CQLQ total score in women versus a 1.26-point (95% CI 0.20–2.31) increase in men (P = 0.020).

Conclusions

Female sex may be associated with worse QoL than men, and women’s QoL may be more significantly impaired as cough symptom deteriorates. Gender difference should be taken into account in the clinical settings and research of cough and cough related QoL.

Trial registration: Chinese Clinical Trial Registry, ChiCTRTRC12002297. Registered 19 June 2012, http://www.chictr.org.cn/abouten.aspx.

Global Physiology and Pathophysiology of Cough: Part 1: Cough Phenomenology - CHEST Guideline and Expert Panel Report

The purpose of this state-of-the-art review is to update the American College of Chest Physicians 2006 guideline on global physiology and pathophysiology of cough. A review of the literature was conducted using PubMed and MEDLINE databases from 1951 to 2019 and using prespecified search terms. We describe the basic phenomenology of cough patterns, behaviors, and morphological features. We update the understanding of mechanical and physiological characteristics of cough, adding a contemporary view of the types of cough and their associated behaviors and sensations. New information about acoustic characteristics is presented, and recent insights into cough triggers and the patient cough hypersensitivity phenotype are explored. Lastly, because the clinical assessment of patients largely focuses on the duration rather than morphological features of cough, we review the morphological features of cough that can be measured in the clinic. This is the first of a two-part update to the American College of Chest Physicians 2006 cough guideline; it provides a more global consideration of cough phenomenology, beyond simply the mechanical aspects of a cough. A greater understanding of the typical features of cough, and their variations, may allow a more informed interpretation of cough measurements and the clinical relevance for patients.

Assessment and management of cough among patients with lung cancer in a radiotherapy department in China: a best practice implementation project

OBJECTIVES

This project aimed to implement an evidence-based practice to assess and manage lung cancer-associated cough, thereby relieving patients' physical pain and psychological challenges and improving their quality of life.

INTRODUCTION

Cough is one of the most common symptoms experienced by patients with lung cancer. If a cough is not proactively managed, patients may develop decreased compliance with treatments and experience a reduced quality of life. Cough assessment and management are essential components of nursing practice that should include evidence-based interventions.

METHODS

Seven evidence-based audit criteria were developed from current evidence. The JBI Practical Application of Clinical Evidence System (PACES) was used to perform a baseline audit on 30 patients and 20 nurses in the Department of Radiotherapy of Nanfang Hospital. The Getting Research into Practice (GRiP) component of PACES was used to identify barriers, strategies, resources and outcomes. Following implementation of strategies to improve compliance, a post-audit was conducted using the same sample size and audit criteria.

RESULTS

The seven evidence-based audit criteria were as follows: 1) Clinicians have received training on the assessment and management of lung cancer-associated cough; 2) In patients with lung cancer-associated cough, a comprehensive assessment was conducted to identify any co-existing causes linked to cough; 3) Any reversible causes of cough were treated according to evidence-based guidelines; 4) A validated scale was used to assess the frequency and severity of cough and distress experienced by the patients; 5) Patients (and their caregivers) have received education regarding management of cough; 6) Patients (and their caregivers) have received training on cough suppression exercises; 7) For symptomatic therapy, a stepwise approach was followed according to evidence-based guidelines. The baseline results showed that compliance rates were 0% for criteria 1, 4 and 5; 70% for criterion 6; 80% for criterion 7; 90% for criterion 3 and 93% for criterion 2. The implementation of strategies to increase compliance with best practice, including establishing training and education programs for nursing staff and patients, utilizing some validated scales to assess the frequency and severity of cough and the distress caused to the patients, and establishing a quality control team to supervise implementation of the assessment and management of cough, achieved ≥ 93% compliance rate for all seven audit criteria.

CONCLUSION

An evidence-based and nurses-oriented best practice for cough assessment and management was successfully established among patients with lung cancer-associated cough.

A new simple score of chronic cough: cough evaluation test

Background

Chronic cough has an important impact on physical, social and psychological aspects. A simple and effective method to assess different aspects of chronic cough severity is required. We aimed to develop a simple, self-completed test, Cough Evaluation Test (CET), to evaluate cough severity and its impact on health.

Method

The items of preliminary CET were generated based on literature review and clinical practice. Items reduction was conducted by modified Delphi method. Patients with chronic cough were recruited to complete CET, Cough Visual Analog Scales (VAS), Mandarin Chinese version of the Leicester Cough Questionnaire (LCQ-MC), and Cough Symptom Score (CSS). Reassessments were performed at 1 week apart before treatment, and after more than 2 weeks treatments. Concurrent validation, internal consistency, repeatability, responsiveness and the minimal important difference (MID) were determined.

Results

CET consists of five items with a 5-point Likert scale (1–5 scaling of items, 5–25 score range). The Cronbach’s alpha values for CET was 0.80. CET showed a stronger correlation with LCQ-MC (r = − 0.74) compared to that between LCQ-MC with VAS (r = − 0.61). CET also showed a stronger correlation with VAS (r = 0.70) compared to that between VAS with other measures. Intraclass correlation coefficients for CET was 0.84. In patients undergoing treatment, CET scores significantly changed (p < 0.0001). The MID of CET was 2.

Conclusion

Cough Evaluate Test is a reliable, valid and responsive tool to simply evaluate impact of cough on physical, social and psychological aspects.

A cross sectional study to determine the prevalence of cough and its impact in patients with lung cancer: a patient unmet need

BACKGROUND

There is absence of literature related to cough prevalence and its characteristics in lung cancer patients, with information deriving only from broader symptoms occurrence studies. The aims of this study were to provide a snapshot of the prevalence of all-cause-cough in lung cancer patients and to characterise cough in terms of its impact and severity.

METHODS

A cross-sectional study recruiting consecutive lung cancer patients over a pre-defined period of time and using cough-specific validated tools in a tertiary referral centre in the UK, including a cough severity VAS and the Manchester Cough in Lung Cancer scale (MCLCS).

RESULTS

Data was collected from 202 patients. All-cause cough prevalence was 57% (through VAS) both in the screened (N = 223) and research (N = 202) population or 67% (through the MCLCS), and cough severity was moderate at a mean of 32 mm (in a 100 mm VAS). Age, sex, smoking status, lung cancer histology, stage and comorbidities were not associated with cough prevalence. The only variable associated with lower cough reports was being 'on anticancer treatment'; fewer patients on treatment reported a cough (40%) compared to those off treatment (54%) (p = 0.04). The impact of cough (as measured by MCLCS) was also significant (mean score = 22). About 18% of patients felt moderate/severe distress from their cough and about 15% often or always reported disturbed sleep due to coughing. Half the patients felt their cough warranted treatment.

CONCLUSIONS

Cough is a common symptom in lung cancer with considerable impact on patients' lives. Cough presence and severity should regularly be assessed in clinical practice. There is an urgent need to focus on developing more potent antitussive treatments and improve the management of this complex and distressing symptom.

Quantitative measurement properties and score interpretation of the Cough Severity Diary in patients with chronic cough

AIMS

The Cough Severity Diary (CSD) was developed in accordance with the FDA guidance for patient-reported outcome measures and is focused on capturing the patient's perception of cough in terms of frequency, intensity, and disruption due to their cough. The measure includes a series of seven items asking patients to rate the frequency (three items), intensity (two items), and disruptiveness (two items) of their cough. The instrument was designed to be completed daily before bedtime, has a recall period of 'today,' and responses to items are entered on an 11-point numeric rating scale ranging from 0 to 10 with anchors on each end. The objective of this analysis was to confirm the domain structure of the CSD and assess its reliability, validity, and responsiveness in adult patients with refractory or unexplained chronic cough (RCC/UCC). Criteria for defining meaningful changes in mean weekly CSD total and domain scores in the context of a clinical trial were also developed.

METHODS

Pooled data from a phase II randomized controlled trial of an investigational treatment for RCC/UCC were analyzed. Participants were non-smokers, had RCC/UCC for ⩾1 year, and a baseline cough severity visual analogue scale (VAS) ⩾40 mm. CSD scores (baseline, week 4), were analyzed; the Leicester Cough Questionnaire (LCQ), cough severity VAS, Patient Global Impression of Change (PGIC), and objective cough frequency counts were used for validation. CSD domain structure (Total, Frequency, Intensity, Disruption) was assessed for scoring.

RESULTS

A total of 253 participants were included (mean age 60.2; 76% female). Global fit of the three-factor CSD was acceptable. For the CSD total score, internal consistency (α = 0.89) and test-retest reliability (intraclass correlation coefficient = 0.68) were high. CSD total scores were correlated with the LCQ total (r = -0.62) and cough severity VAS (r = 0.84). Participants with a PGIC score of 1 or 2 (most improved groups) had the greatest mean score improvement on the CSD Total (Day 0 to Day 28), supporting responsiveness (similar findings for subscales). A change threshold of ⩾1.3-point reduction on the total and subscale scores is appropriate to define clinically meaningful improvement.

CONCLUSION

The CSD is a reliable, valid, and responsive measure of cough symptom severity in patients with refractory or unexplained chronic cough and fit-for-purpose for assessing changes in cough severity in clinical trials. The reviews of this paper are available via the supplemental material section.

[From acute cough to chronic cough in adults: Overview on a common reason for consultation]

Cough is divided into two categories: acute cough lasting less than 3 weeks, and chronic cough lasting more than 8 weeks. Acute cough is usually triggered by a viral infection of the upper airways. Evidence of treatment effectiveness is low and management of acute cough is complex in clinical practice. Chronic cough is a common reason for consultation in medicine. The most frequent causes are upper airway diseases, gastroesophageal reflux disease, asthma, eosinophilic bronchitis, and drugs. Before investigation, smoking cessation and drug withdrawal must be achieved for 4 to 6 weeks. Once this step is completed, simple investigations have to be performed in order to find common causes of chronic cough (questioning, physical examination, spirometry, chest X-ray). If no causes have been identified or cough remains despite optimal treatment, exhaustive exploration has to be performed to rule out rare causes. A chronic cough hypersensitivity syndrome is suggested if any causes have been found despite exhaustive assessment or if cough remains with optimal treatments. This syndrome is characterized by an increase in the sensitivity of cough peripheral receptors and is not sensitive to usual therapies. The therapeutic options are limited but innovative treatments such as P2X3 receptor antagonists are in development.

Sound: a non-invasive measure of cough intensity

Introduction

Cough intensity is an important determinant of cough severity reported by patients. Cough sound analysis has been widely validated for the measurement of cough frequency but few studies have validated its use in the assessment of cough strength. We investigated the relationship between cough sound and physiological measures of cough strength.

Methods

32 patients with chronic cough and controls underwent contemporaneous measurements of voluntary cough sound, flow and oesophageal pressure. Sound power, peak energy, rise-time, duration, peak-frequency, bandwidth and centroid-frequency were assessed and compared with physiological measures. The relationship between sound and subjective cough strength Visual Analogue Score (VAS), the repeatability of cough sounds and the effect of microphone position were also assessed.

Results

Sound power and energy correlated strongly with cough flow (median Spearman’s r=0.87–0.88) and oesophageal pressure (median Spearman’s r=0.89). Sound power and energy correlated strongly with cough strength VAS (median Spearman’s r=0.84–0.86) and were highly repeatable (intraclass correlation coefficient=0.93–0.94) but both were affected by change in microphone position.

Conclusions

Cough sound power and energy correlate strongly with physiological measures and subjective perception of cough strength. Power and energy are highly repeatable measures but the microphone position should be standardised. Our findings support the use of cough sound as an index of cough strength.

The Intensity of Voluntary, Induced, and Spontaneous Cough

BACKGROUND

The intensity of cough is an important determinant of cough severity. Few studies have quantified cough intensity in patients with chronic cough with objective measures. We investigated the intensity of voluntary, induced, and spontaneous cough in patients with chronic cough and healthy control subjects.

METHODS

Patients with chronic cough and control subjects underwent physiologic assessment of the intensity of maximum voluntary, capsaicin-induced, and spontaneous cough. Assessments included measurement of gastric pressure (Pga) and esophageal pressure (Pes) during cough, peak cough flow (PCF), expiratory muscle strength (twitch gastric pressure [TwPga]), and cough compression phase duration (CPD). Subjective perception of cough intensity was assessed using a visual analog scale (VAS).

RESULTS

Pes, Pga, and PCF during maximum voluntary cough were significantly greater in patients with chronic cough compared with control subjects (P = .003-.042). There was no difference in TwPga between patients and control subjects. CPD was increased in female patients compared with control subjects (mean ± SD, 0.50 ± 0.22 s vs 0.28 ± 0.17 s; P = .007). Mean ± SD Pes during spontaneous cough was comparable to induced cough (128 ± 28 cm H2O vs 122 ± 37 cm H2O, P = .686) but less than maximum voluntary cough (170 ± 46 cm H2O, P = .020). Median within-subject correlation coefficients between cough intensity VAS and Pes, Pga, and PCF were r = 0.82 to 0.86.

CONCLUSIONS

Maximum voluntary cough intensity was increased in patients with chronic cough compared with control subjects. There was no significant difference in expiratory muscle contractility. Further studies should evaluate the compressive phase of cough in more detail. Physiologic measures of cough intensity correlated strongly with subjective perception of intensity in patients with chronic cough and may be relevant objective outcome measures for clinical studies.

A longitudinal assessment of acute cough

RATIONALE

Cough can be assessed with visual analog scales (VAS), health status measures, and 24-hour cough frequency monitors (CF(24)). Evidence for their measurement properties in acute cough caused by upper respiratory tract infection (URTI) and longitudinal data is limited.

OBJECTIVES

To assess cough longitudinally in URTI with subjective and objective outcome measures and determine sample size for future studies.

METHODS

Thirty-three previously healthy subjects with URTI completed cough VAS, Leicester Cough Questionnaire (LCQ-acute), and CF(24) monitoring (Leicester Cough Monitor) on three occasions, 4 days apart. Changes in subjects' condition were assessed with a global rating of change questionnaire. The potential for baseline first-hour cough frequency (CF(1)), VAS, and LCQ to identify low CF(24) was assessed.

MEASUREMENTS AND MAIN RESULTS

Mean ± SD duration of cough at visit 1 was 4.1 ± 2.5 days. Geometric mean ± log SD baseline CF(24) and median (interquartile range) cough bouts were high (14.9 ± 0.4 coughs/h and 85 [39-195] bouts/24 h). Health status was severely impaired. There was a significant reduction in CF(24) and VAS, and improvement in LCQ, from visits 1-3. At visit 3, CF(24) remained above normal limits in 52% of subjects. The smallest changes in CF(24), LCQ, and VAS that subjects perceived important were 54%, 2- and 17-mm change from baseline, respectively. The sample sizes required for parallel group studies to detect these changes are 27, 51, and 25 subjects per group, respectively. CF(1) (<20.5 coughs/h) was predictive of low CF(24).

CONCLUSIONS

CF(24), VAS, and LCQ are responsive outcome tools for the assessment of acute cough. The smallest change in cough frequency perceived important by subjects is 54%. The sample sizes required for future studies are modest and achievable.

Four-hour cough frequency monitoring in chronic cough

BACKGROUND

The recent development of automated cough monitors has enabled objective assessment of cough frequency. A study was undertaken to determine whether short-duration recordings( < 6 h) accurately reflect 24-h cough frequency and to investigate their responsiveness.

METHODS

One hundred adults with chronic cough underwent 24-h cough frequency monitoring with the Leicester Cough Monitor and completed cough visual analog scales (VASs) and the Leicester Cough Questionnaire (LCQ). Cough recordings were analyzed using customized software to derive cough frequencies from 1 to 6 h and 24-h recordings. Responsiveness was assessed with repeat assessments following therapeutic trials.

RESULTS

The median (interquartile range) 24-h cough frequency was 11.5 (5.8-26.6) coughs/h. Four hours was considered the shortest recording duration that represented 24-h cough frequency( ρ= 0.9, P ≤ .001). Median 4-h cough frequency was 16.6 (7.3-36.8) coughs/h. Both 4-h and 24-h cough frequency correlated moderately with cough VAS ( ρ= 0.49, P ≤ .01 and ρ= 0.44, P ≤ .01)and LCQ ( ρ = - 0.48, P ≤ .01; ρ = - 0.50, P ≤ .01). Four-hour cough frequency was responsive to improvements in cough severity following trials of therapy.

CONCLUSIONS

Four-hour cough frequency correlates highly with 24-h cough frequency recordings and relates equally well with subjective measures in chronic cough. Short-duration cough monitoring could be a practical tool to validate the presence of cough and assess response to trials of therapy in the clinic setting.

A novel approach to studying the relationship between subjective and objective measures of cough

BACKGROUND

Currently, no data are available on the relationship between changes in objective and subjective measures of cough, the magnitude of change in cough frequency perceived by patients as clinically meaningful, or the sample sizes required to show significant changes in cough therapeutic trials. Because patients anecdotally report reductions in cough severity while undergoing esophageal testing, we aimed to address these issues by assessing objective and subjective measures of cough with and without an esophageal catheter.

METHODS

Twenty-four-hour cough monitoring was performed on two occasions, with and without esophageal impedance/pH monitoring in 62 patients with chronic cough (mean age 56.8 years [SD±10.8]; 43 women; median cough duration 3.3 years [interquartile range (IQR), 2.0-10.0]). Cough was assessed objectively measuring coughs per hour and subjectively using a numerical cough score and a visual analog scale (VAS), scored separately for day and night, and then averaged to represent each 24-h period.

RESULTS

Objective cough frequency was reduced by a median of 33.3% (IQR, -68.8% to -13.0%; P<.001) with the catheter. The averaged day and night cough scores and VAS scores also significantly decreased, but changes in these did not correlate with decreases in cough frequency. Sample-size calculations suggested that crossover designs using objective cough frequency may be preferable in therapeutic trials.

CONCLUSIONS

These observations provide useful information on the reduction in objective cough frequency scored as an improvement by patients with chronic cough and offer guidance for the design and powering of future therapeutic trials.

TRIAL REGISTRY

ISRCTN; No.: ISRCTN62337037; URL: http://www.controlled-trials.com.

Measuring cough severity: development and pilot testing of a new seven-item cough severity patient-reported outcome measure

Objective: Although chronic and subacute cough are clinically problematic and a target of therapeutic interventions, there are no validated cough severity patient-reported outcome (PRO) instruments for comprehensively evaluating cough severity in clinical trials. The Cough Severity Diary (CSD) is a simple, seven-item daily diary developed to meet this need. The objective of this study was to assess preliminary measurement characteristics in a small sample of patients with chronic or subacute cough.

Methods: Thirty-nine patients (24 chronic; 15 subacute) participated in a two-week prospective pilot study. Patients completed the CSD each evening and validation instruments (cough severity visual analog scale [VAS], Leicester Cough Questionnaire [LCQ], Medical Outcomes Study 36-Item Short Form [SF-36], Work Productivity Index [WPAI], MOS Sleep Scale [MOS-SS]) at baseline, days 8 and 15, and a global rating of change at days 8 and 15.

Results: Confirmatory factor analyses supported three severity subscales: frequency (three items), intensity (two items), and disruption (two items) (χ2 = 10.57 (11)). For the CSD total score, internal consistency (α) on day 1 was 0.89, and on day 8 was 0.96; reproducibility (intraclass correlation coefficients [ICC]) was 0.68 on day 1 to day 8 and 0.94 on day 8 to day 15. CSD total scores correlated with the VAS (r = 0.84, p < 0.0001), LCQ total (r =-0.62, p < 0.0001) and subscale scores (r =-0.43, p < 0.01 to -0.60, p < 0.0001), and WPAI subscale scores (r = 0.27 (ns) to 0.51, p < 0.01). No significant relationships with SF-36 or MOS-SS were found. Subacute patients showed significant improvement over time (F = 3.20, p < 0.05).

Conclusions: Results suggest that the CSD is ready for further testing in larger naturalistic studies or as an exploratory endpoint in clinical trials of patients with subacute or chronic cough.

Quality of life in patients with chronic cough

Chronic cough is a relatively common symptom for which effective, acceptable treatments are lacking. Many patients suffer frequent coughing over several years without resolution and this has significant physical, social and psychological consequences. The recent development of cough-specific quality-of-life tools now allows quantification of the burden of coughing both in patients specifically presenting with chronic cough and also in common respiratory conditions.