Assessment of Intervention Fidelity and Recommendations for Researchers Conducting Studies on the Diagnosis and Treatment of Chronic Cough in the Adult: CHEST Guideline and Expert Panel Report

Exploring fidelity of enactment in a cluster randomised controlled trial testing the effectiveness of 'gatekeeper' training for pesticide vendors in reducing self-poisoning in rural Sri Lanka: protocol for a multimethod qualitative study

INTRODUCTION

Pesticide self-poisoning causes severe health and socioeconomic hardship in low- and middle-income countries, including Sri Lanka. A stepped-wedge cluster randomised controlled trial (cRCT) has been designed to test whether 'gatekeeper' training for pesticide vendors reduces pesticide self-poisoning in rural Sri Lanka (Vendor cRCT). Ensuring intervention fidelity in RCTs is essential for consistently replicating interventions, accurately assessing their impact and improving outcomes. Thus, the overarching goal of this proposed study is to explore to what extent the pesticide vendors use the 'gatekeeper' strategies.

METHODS AND ANALYSIS

A multimethod qualitative research design is being used to explore the pesticide-selling behaviours of vendors after the 'gatekeeper' training. A subsample of the Vendor cRCT Study population is being recruited using a stratified purposive sampling method in all six intervention districts in Sri Lanka to ensure that the sample is representative of the pesticide vendors in the study area. Participant diaries, observations and focus group discussions are being adopted to collect data. Data triangulation will be performed and data will be analysed thematically.

ETHICS AND DISSEMINATION

The study was approved by the Ethics and Research Committee, Faculty of Medicine and Allied Sciences, at the Rajarata University of Sri Lanka (ERC/2023/09). All participants will provide informed consent. Findings will be disseminated in scientific peer-reviewed journals and conference presentations.

Underreporting of implementation strategies and barriers in physical activity interventions for young people at risk of problematic substance use: a brief report

BACKGROUND

Several studies have assessed whether physical activity interventions can reduce substance use in young people at risk of problematic substance use. This report identifies and describes the reporting of implementation characteristics within published studies of physical activity interventions for young people at risk of problematic substance use and provides recommendations for future reporting.

METHODS

Reported implementation strategies (including intervention manualization), barriers, implementation fidelity, and personnel acceptance were extracted from studies of physical activity interventions for young people aged 12-25 years at risk of problematic substance use that were included in a previous systematic review of intervention efficacy.

RESULTS

Implementation strategies were reported in less than half of the included studies (42.9%), implementation barriers in only 10.7% of studies, intervention fidelity in 21.4%, and personnel acceptance in a single study (3.6%).

CONCLUSIONS

Results indicate insufficient reporting of implementation strategies, barriers, fidelity, and personnel acceptance. Consideration of implementation characteristics is essential for implementing physical activity interventions in practice. Inadequate or limited reporting of these characteristics may contribute to delayed uptake and adoption of evidence-based interventions in clinical practice. Recommendations to improve the reporting of implementation information include integrating standards for reporting implementation characteristics into existing reporting guidelines, developing an international taxonomy of implementation strategies, and upskilling intervention researchers in the fundamentals of implementation science.

Efficacy and Tolerability of Gefapixant for Treatment of Refractory or Unexplained Chronic Cough: A Systematic Review and Dose-Response Meta-Analysis

Importance

Gefapixant represents an emerging therapy for patients with refractory or unexplained chronic cough.

Objective

To evaluate the efficacy and tolerability of gefapixant for the treatment of adults with refractory or unexplained chronic cough.

Data Sources

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science from November 2014 to July 2023.

Study Selection

Two reviewers independently screened for parallel and crossover randomized clinical trials (RCTs) that compared, in patients with refractory or unexplained chronic cough, either gefapixant with placebo, or 2 or more doses of gefapixant with or without placebo.

Data Extraction and Synthesis

Two reviewers independently extracted data. A frequentist random-effects dose-response meta-analysis or pairwise meta-analysis was used for each outcome. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach was used to rate the certainty in whether patients would perceive the effects as important (greater than the minimal important difference [MID]) or small (less than the MID).

Main Outcomes and Measures

Cough frequency (measured using the VitaloJAK cough monitor; MID, 20%), cough severity (measured using the 100-mm visual analog scale [VAS]; higher score is worse; MID, 30 mm), cough-specific quality of life (measured using the Leicester Cough Questionnaire [LCQ]; score range, 3 [maximal impairment] to 21 [no impairment]; MID, 1.3 points), treatment-related adverse events, adverse events leading to discontinuation, and taste-related adverse events.

Results

Nine RCTs including 2980 patients were included in the primary analysis. Compared with placebo, gefapixant (45 mg twice daily) had small effects on awake cough frequency (17.6% reduction [95% CI, 10.6%-24.0%], moderate certainty), cough severity on the 100-mm VAS (mean difference, -6.2 mm [95% CI, -4.1 to -8.4]; high certainty), and cough-specific quality of life on the LCQ (mean difference, 1.0 points [95% CI, 0.7-1.4]; moderate certainty). Compared with placebo, gefapixant (45 mg twice daily) probably caused an important increase in treatment-related adverse events (32 more per 100 patients [95% CI, 13-64 more], moderate certainty) and taste-related adverse events (32 more per 100 patients [95% CI, 22-46 more], high certainty). High-certainty evidence suggests that gefapixant (15 mg twice daily) had small effects on taste-related adverse events (6 more per 100 patients [95% CI, 5-8 more]).

Conclusions and Relevance

Compared with placebo, gefapixant (45 mg orally twice daily) led to modest improvements in cough frequency, cough severity, and cough-specific quality of life but increased taste-related adverse events.

Managing Chronic Cough Associated with Idiopathic Pulmonary Fibrosis - Will Nalbuphine Fill an Unmet Need?

In this issue of NEJM Evidence, Maher et al.1 report the results of a randomized, controlled, 22-day treatment crossover trial comparing the antitussive effect of extended-release nalbuphine, an opioid agonist-antagonist, with placebo in a cohort of patients with definite or probable idiopathic pulmonary fibrosis (IPF). In this small, short-term trial of 38 evaluable patients, the active drug was associated with a 75.1% reduction in daytime objective cough frequency (the primary outcome) compared with a 22.6% reduction in placebo-treated patients, yielding a substantial and statistically significant 52.5 percentage point placebo-adjusted change from baseline.

Cough Hypersensitivity Syndrome: Why Its Use Is Inappropriate in Children

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

Intervention Fidelity to VITAL Start (Video Intervention to Inspire Treatment Adherence for Life) in a Randomized Controlled Trial Among Women Living With HIV in Malawi

BACKGROUND

Intervention effectiveness in a randomized controlled trial is attributed to intervention fidelity. Measuring fidelity has increasing significance to intervention research and validity. The purpose of this article is to describe a systematic assessment of intervention fidelity for VITAL Start (Video intervention to Inspire Treatment Adherence for Life)-a 27-minute video-based intervention designed to improve antiretroviral therapy adherence among pregnant and breastfeeding women.

METHOD

Research Assistants (RAs) delivered VITAL Start to participants after enrolment. The VITAL Start intervention had three components: a pre-video orientation, video viewing, and post-video counseling. Fidelity assessments using checklists comprised self (RA assessment) and observer (Research Officers, also known as ROs) assessment. Four fidelity domains (adherence, dose, quality of delivery, and participant responsiveness) were evaluated. Score scale ranges were 0 to 29 adherence, 0 to 3 dose, 0 to 48 quality of delivery and 0 to 8 participant responsiveness. Fidelity scores were calculated. Descriptive statistics summarizing the scores were performed.

RESULTS

In total, eight RAs delivered 379 VITAL Start sessions to 379 participants. Four ROs observed and assessed 43 (11%) intervention sessions. The mean scores were 28 (SD = 1.3) for adherence, 3 (SD = 0) for dose, 40 (SD = 8.6) for quality of delivery, and 10.4 (SD = 1.3) for participant responsiveness.

CONCLUSION

Overall, the RAs successfully delivered the VITAL Start intervention with high fidelity. Intervention fidelity monitoring should be an important element of randomized control trial design of specific interventions to ensure having reliable study results.

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

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

A validity study to consult on a protocol of a home hazard management program for falls prevention among community dwelling stroke survivors

OBJECTIVE

A fall after a stroke is common but the consequences can be devastating not only for the stroke survivors, but also for caregivers, healthcare, and the society. However, research on falls prevention among the stroke population are limited, particularly on home hazards assessment and home modifications, demanding for a study to be conducted. The aim of the study is to validate the protocol and content of a home hazard management program guided by the Person-Environment-Occupation (PEO) Model for falls prevention among community dwelling stroke survivors.

METHOD

Researchers developed their own questionnaire for content validation which consist of 23 items that covers two domains, namely justification for telehealth home hazard management practice and the protocol's overall methodology. Occupational therapists with at least one year of experience in conducting a home hazard assessment were consulted for the content validation of a two-group clinical controlled trial protocol utilizing a home hazard assessment, home modifications and education over the usual care. Written consent was obtained prior to the study. The occupational therapists were given a Google Form link to review the protocol and intervention based on the questionnaire and rated each item using a four-point Likert scale for relevance and feasibility. Open-ended feedback was also recorded on the google form. Content Validity Index (CVI), Modified Kappa Index and Cronbach's Alpha was calculated for the content validity and reliability analysis.

RESULTS

A total of sixteen occupational therapists participated in the study. 43.7% of participants had a master's degree, 93.7% worked in the government sector and 56.2% had six years and more experience on conducting home hazard assessments. Content validity of the protocol is satisfactory for relevancy and feasibility (CVI = 0.84, ranging from 0.5 to 1.00), and for the reliability (α = 0.94 (relevance) and α = 0.97 (feasibility), respectively. The Modified Kappa ranged from 0.38 to 1.00 for all items. Feedback was also received regarding the design and procedure of the study protocol which included participant's selection criteria, sample size, equipment provided, cost, location, and care for the participants during the intervention.

CONCLUSIONS

Introducing a home hazard management program to prevent falls among the stroke population is viewed relevant and feasible. Practical suggestions from the consultation panel were adopted, and minor adjustments were required to strengthen the protocol's overall methodology. This study established a rigorous and robust experimental protocol for future undertaking.

The Evolving Clinical Practice of Chronic Cough

Chronic cough, defined as a cough lasting for greater than 8 weeks, accounts for a substantial number of primary care and specialist consultations in the United States. Although cough can arise from a myriad number of serious respiratory diseases, attention has traditionally focused on diagnosing and treating gastroesophageal reflux, upper airway cough syndrome, and eosinophilic airway inflammation (asthma and nonasthmatic eosinophilic bronchitis) in patients with normal chest imaging. The newly described paradigm and entity of cough hypersensitivity syndrome (CHS) becomes useful when the etiology of cough remains elusive or when the cough remains refractory despite appropriate therapy for underlying causes. We present an update on the evolving understanding of refractory chronic cough and/or unexplained chronic cough as manifestations of laryngeal hypersensitivity and CHS. This includes a focus on understanding the pathophysiology underlying current and novel therapeutics for CHS, while also ensuring that common causes of chronic cough continue to be evaluated and treated in a systematic multidisciplinary manner.

Identifying active ingredients, working mechanisms and fidelity characteristics reported in smoking cessation interventions in Dutch primary care: a systematic review

Background

Evidence-based smoking cessation interventions provided by healthcare professionals can be successful in helping citizens to quit smoking. Yet, evidence is needed about the active ingredients of these interventions, how these ingredients work and how they are implemented in practice. Such knowledge is required to effectively support healthcare professionals to optimally put evidence-based smoking cessation interventions to (inter)national practice.

Objective

To identify active ingredients (including behavior change techniques), mechanisms of action and implementation fidelity reported in smoking cessation interventions in Dutch primary care settings and to relate these to intervention effectiveness.

Methods

A systematic review was conducted by searching nine national intervention or funding databases, five international scientific databases and consulting 17 national smoking cessation experts. Out of 1066 identified manuscripts, 40 interventions were eligible for this review. Based on published protocols, information regarding behavior change techniques and mechanisms of action was systematically abstracted. Additionally, information regarding study characteristics and other active ingredients, effects on smoking behavior and implementation fidelity was abstracted. Comparative effectiveness concerning abstracted intervention characteristics was qualitatively explored.

Results

Active ingredients, mechanisms of action and implementation fidelity were moderately to poorly reported. Interventions applying behavior change techniques and interventions with a single behavioral target (i.e. smoking-only versus multiple behaviors) seemed to provide stronger evidence for successfully changing smoking behavior.

Conclusion

Attention to and reporting on interventions’ active ingredients (e.g. behavior change techniques), mechanisms of action and implementation fidelity are prerequisites for developing more effective evidence-based smoking cessation interventions to be successfully implemented in primary healthcare.

Implications

This systematic review provides an overview of smoking cessation interventions in Dutch primary care settings, identified since the year 2000. Smoking cessation support is offered in various forms, but our qualitative findings show that interventions including more behavior change techniques and interventions targeting only smoking cessation (compared to multiple behaviors) might be more effective. Results also show that—based on available intervention reports—it is difficult to distinguish patterns of active ingredients (such as behavior change techniques), mechanisms of action and fidelity of implementation in relation to interventions’ effectiveness. This means (quality of) reporting on these intervention characteristics should improve.

Addressing unmet needs for diagnosis and management of chronic cough in the primary care setting

Chronic cough (i.e. cough lasting >8 weeks) has a global prevalence of approximately 10% and is associated with substantial patient burden, including social, psychological, and physical impairments. This burden can be long-lasting, with some patients experiencing cough for many years. Although chronic cough is often a symptom of respiratory diseases (e.g. interstitial lung disease, chronic obstructive pulmonary disease) or is associated with comorbid conditions (e.g. asthma, gastroesophageal reflux disease) and may resolve after targeted treatment of these conditions, some patients continue to cough despite optimal treatment of associated conditions (refractory chronic cough (RCC)) or have no identifiable conditions presumed to be contributing to the cough (unexplained chronic cough (UCC)). As both RCC and UCC are diagnoses of exclusion, it is critical to perform a thorough initial patient assessment with adherence to diagnostic guidelines to accurately identify RCC and UCC and provide appropriate treatment. Primary care physicians may be in an important position to provide the initial diagnostic workup of patients with chronic cough as well as identify when referral to specialists (e.g. pulmonologists, allergists, otolaryngologists) is appropriate. In this narrative review, current diagnosis and management guidelines for chronic cough are summarized and recommendations for diagnostic workup in a primary care setting are provided. Increased appreciation of chronic cough as a distinct condition, rather than as only a symptom of other diseases, may help overcome current challenges in diagnosing and managing chronic cough and reduce patient burden.

Characterization of Patients With Refractory or Unexplained Chronic Cough Participating in a Phase 2 Clinical Trial of the P2X3-Receptor Antagonist Gefapixant

Purpose

This analysis assesses clinical characteristics of patients with refractory chronic cough (RCC) or unexplained chronic cough (UCC) enrolled in a phase 2 study to better understand this patient population.

Methods

Patients with RCC/UCC lasting for ≥ 1 year and cough severity visual analog scale (VAS) score of > 40 mm at screening were eligible. Demographics, clinical characteristics, and medical history were collected at baseline. Cough-related measures included cough severity VAS, Cough Severity Diary (CSD), Leicester Cough Questionnaire (LCQ), and a structured cough-trigger questionnaire. Medication history included all medications 30 days before screening and chronic cough treatments within 1 year before screening. Data were summarized using descriptive statistics.

Results

Patients (N = 253; female, 76%; mean age, 60 years) had severe (mean cough severity VAS, 57.5 mm) and long-lasting (median duration, 11 years) cough. The most burdensome self-reported aspects included psychological and social factors (LCQ) and cough frequency and intensity (CSD). Patient-reported triggers were consistent with cough hypersensitivity (e.g., 95% to 96% reported irritation or tickle in throat). Common reported comorbidities included gastroesophageal reflux disease (GERD; 56%), allergic rhinitis (47%), and asthma (30%); 12% of patients had been diagnosed with all 3 conditions. The most common prior medications included inhaled or oral steroids (21%), antihistamines (15%), and antacids (15%).

Conclusion

Patients with RCC/UCC had severe, long-lasting, and burdensome cough with clinical features of cough hypersensitivity. Many patients had been diagnosed with GERD, allergic rhinitis, and asthma but had a persistent cough despite treatment of these conditions.

Trial registration: ClinicalTrials.gov, NCT02612610; registered November 20, 2015

Inflammatory Subtypes in Classic Asthma and Cough Variant Asthma

Background

Measurement of sputum is used to define airway inflammatory phenotypes. Cough variant asthma (CVA) is considered to be the initial stage of classic asthma (CA). The aim of this study was to describe the association between the different subtypes of CVA and CA.

Methods

A total of 459 patients with CVA and CA were screened for the study. All included patients performed spirometry, underwent a bronchial challenge with methacholine and induced sputum according to the guidelines.

Results

A higher frequency of female patients were found with CVA and the eosinophilic airway inflammation of CVA than in CA and the noneosinophilic airway inflammation of CA (p=0.004 and p=0.024, respectively). Bronchial hyper-responsiveness (BHR) was lower in eosinophilic CVA and CA (p=0.006), while no difference was found in noneosinophilic CVA and CA. Association between the percentage of sputum eosinophils and the FEV₁ level fell below 20% of the baseline value (PD₂₀) in CVA and CA (r= −0.1245, p=0.0357 and r= −0.2148, p=0.0014, respectively).

Conclusion

Eosinophilia may be associated with more severe disease, yet there was no difference in spirometry between the eosinophilic and noneosinophilic groups, and the BHR difference was not dramatic.

Identifying and Characterizing a Chronic Cough Cohort Through Electronic Health Records

BACKGROUND

Chronic cough (CC) of 8 weeks or more affects about 10% of adults and may lead to expensive treatments and reduced quality of life. Incomplete diagnostic coding complicates identifying CC in electronic health records (EHRs). Natural language processing (NLP) of EHR text could improve detection.

RESEARCH QUESTION

Can NLP be used to identify cough in EHRs, and to characterize adults and encounters with CC?

STUDY DESIGN AND METHODS

A Midwestern EHR system identified patients aged 18 to 85 years during 2005 to 2015. NLP was used to evaluate text notes, except prescriptions and instructions, for mentions of cough. Two physicians and a biostatistician reviewed 12 sets of 50 encounters each, with iterative refinements, until the positive predictive value for cough encounters exceeded 90%. NLP, International Classification of Diseases, 10th revision, or medication was used to identify cough. Three encounters spanning 56 to 120 days defined CC. Descriptive statistics summarized patients and encounters, including referrals.

RESULTS

Optimizing NLP required identifying and eliminating cough denials, instructions, and historical references. Of 235,457 cough encounters, 23% had a relevant diagnostic code or medication. Applying chronicity to cough encounters identified 23,371 patients (61% women) with CC. NLP alone identified 74% of these patients; diagnoses or medications alone identified 15%. The positive predictive value of NLP in the reviewed sample was 97%. Referrals for cough occurred for 3.0% of patients; pulmonary medicine was most common initially (64% of referrals).

LIMITATIONS

Some patients with diagnosis codes for cough, encounters at intervals greater than 4 months, or multiple acute cough episodes may have been misclassified.

INTERPRETATION

NLP successfully identified a large cohort with CC. Most patients were identified through NLP alone, rather than diagnoses or medications. NLP improved detection of patients nearly sevenfold, addressing the gap in ability to identify and characterize CC disease burden. Nearly all cases appeared to be managed in primary care. Identifying these patients is important for characterizing treatment and unmet needs.

Maintaining Intervention Fidelity When Using Technology Delivery Across Studies

The current standard in healthcare research is to maintain scientific fidelity of any intervention being tested. Fidelity is defined as the consistent delivery of interventions that ensures that all participants are provided the same information, guidance, and/or materials. Notably, the methods for ensuring fidelity of intervention delivery must also be consistent. This article describes our Intervention and Technology Delivery Fidelity Checklists used to ensure consistency. These checklists were completed by trained nurse observers who rated the intervention implementation and the technology delivery. Across our clinical trials and pilot studies, the fidelity scores were tabulated and compared. Intervention information and materials were delivered by a variety of devices including telehealth monitors, videophones, and/or iPads. Each of the devices allows audiovisual connections between health professionals from their offices and patients and participants in their homes. Our checklists guide the monitoring of fidelity of technology delivery. Overall checklist ratings across our studies demonstrate consistent intervention, implementation, and technology delivery approaches. Uniquely, the fidelity checklist verifies the interventionist's correct use of the technology devices to ensure consistent audiovisual delivery. Checklist methods to ensure intervention fidelity and technology delivery are essential research procedures, which can be adapted for use by researchers across multiple disciplines.

Perspectives on neuroinflammation contributing to chronic cough

Chronic cough can be a troublesome clinical problem. Current thinking is that increased activity and/or enhanced sensitivity of the peripheral and central neural pathways mediates chronic cough via processes similar to those associated with the development of chronic pain. While inflammation is widely thought to be involved in the development of chronic cough, the true mechanisms causing altered neural activity and sensitisation remain largely unknown. In this back-to-basics perspective article we explore evidence that inflammation in chronic cough may, at least in part, involve neuroinflammation orchestrated by glial cells of the nervous system. We summarise the extensive evidence for the role of both peripheral and central glial cells in chronic pain, and hypothesise that the commonalities between pain and cough pathogenesis and clinical presentation warrant investigations into the neuroinflammatory mechanisms that contribute to chronic cough. We open the debate that glial cells may represent an underappreciated therapeutic target for controlling troublesome cough in disease.

ERS guidelines on the diagnosis and treatment of chronic cough in adults and children

These guidelines incorporate the recent advances in chronic cough pathophysiology, diagnosis and treatment. The concept of cough hypersensitivity has allowed an umbrella term that explains the exquisite sensitivity of patients to external stimuli such a cold air, perfumes, smoke and bleach. Thus, adults with chronic cough now have a firm physical explanation for their symptoms based on vagal afferent hypersensitivity. Different treatable traits exist with cough variant asthma (CVA)/eosinophilic bronchitis responding to anti-inflammatory treatment and non-acid reflux being treated with promotility agents rather the anti-acid drugs. An alternative antitussive strategy is to reduce hypersensitivity by neuromodulation. Low-dose morphine is highly effective in a subset of patients with cough resistant to other treatments. Gabapentin and pregabalin are also advocated, but in clinical experience they are limited by adverse events. Perhaps the most promising future developments in pharmacotherapy are drugs which tackle neuronal hypersensitivity by blocking excitability of afferent nerves by inhibiting targets such as the ATP receptor (P2X3). Finally, cough suppression therapy when performed by competent practitioners can be highly effective. Children are not small adults and a pursuit of an underlying cause for cough is advocated. Thus, in toddlers, inhalation of a foreign body is common. Persistent bacterial bronchitis is a common and previously unrecognised cause of wet cough in children. Antibiotics (drug, dose and duration need to be determined) can be curative. A paediatric-specific algorithm should be used.

Bronchoscopy for Chronic Unexplained Cough: Use of Biopsies and Cultures Increase Diagnostic Yield

BACKGROUND

Prior studies assessing the diagnostic utility of bronchoscopy for chronic unexplained cough have focused primarily on identifying endobronchial anomalies to determine chronic cough etiology. On the basis of our institutional experience, expanding bronchoscopy to include cultures and biopsies can considerably increase its diagnostic yield for identifying the etiology of chronic unexplained cough.

MATERIALS AND METHODS

This retrospective review analyzed bronchoscopies conducted in our institution between 2013 and 2017. Eligibility criteria were bronchoscopies conducted for chronic unexplained cough for which no etiology had been identified before the bronchoscopy. Microbiology, pathology, and cytology results from bronchoscopy were reviewed to identify the etiology of the cough.

RESULTS

Over the study period, 169 bronchoscopies met the eligibility criteria. The average patient age at bronchoscopy was 59.7±14.8 years; 61% were female individuals. Direct visualization identified anatomic etiologies in 48 (28%) patients, most commonly tracheobronchomalacia, and less common conditions, such as tracheobronchopathia osteochondroplastica. Microbiology cultures were positive in 33 (20%) patients, principally Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and nontuberculosis mycobacterium. Pathology results from endobronchial biopsies identified respiratory conditions associated with cough, primarily eosinophilic bronchitis (n=15), as well as neurofibromatosis (n=1) and amyloidosis (n=1). Cytology results did not reveal alternate diagnoses not previously identified.

CONCLUSION

Inclusion of bronchial washings and endobronchial biopsies during bronchoscopy for chronic unexplained cough increased diagnostic yield from 28%, attributable to directly visualized anatomic etiologies, to 41%. The addition of microbiology cultures and pathology analysis significantly increased the diagnostic yield of bronchoscopy in identifying the potential etiology of chronic heretofore unexplained cough.

Controversies in Cough Management: An Indian Perspective

Chronic cough is one of the most common symptoms for patients-seeking consultation in an outpatient clinic. It is associated with substantial psychological, physical, and social burdens and impaired quality of life. This review highlights some of the major diagnostic and management challenges confronted in the field of cough with a special focus on the Indian perspective. Heterogeneity in definitions and classifications and challenges associated with over-the-counter drug use and irrational drug use are some of the major controversies. Streamlined diagnostic approach involving a combination of subjective and objective tools, evidence-based amendments in clinical practice, and stringent implementation of regulatory guidelines are mandatory to address controversies in cough management in developing countries.

Managing patients with chronic cough: challenges and solutions

Chronic cough is a common complaint and a frequent cause of medical consultation. Its management can be difficult. We present here an overview of the current guidelines for the management of chronic cough. Different steps are detailed, including the initial research of an obvious etiology and alert signs that should lead to further investigation of underlying condition. The diagnosis of the most frequent causes: asthma, non-asthmatic eosinophilic bronchitis, gastroesophageal reflux disease and upper airway cough syndrome should be considered, assessed and treated accordingly. Recent advances have been made in the comprehension of refractory chronic cough pathophysiology as well as its pharmacologic and non-pharmacologic treatment, especially speech pathology therapy.

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

BACKGROUND

We performed systematic reviews using the population, intervention, comparison, outcome (PICO) format to answer the following key clinical question: Are the CHEST 2006 classifications of acute, subacute and chronic cough and associated management algorithms in adults that were based on durations of cough useful?

METHODS

We used the CHEST Expert Cough Panel's protocol for the systematic reviews and the American College of Chest Physicians (CHEST) methodological guidelines and Grading of Recommendations Assessment, Development, and Evaluation framework. Data from the systematic reviews in conjunction with patient values and preferences and the clinical context were used to form recommendations or suggestions. Delphi methodology was used to obtain the final grading.

RESULTS

With respect to acute cough (< 3 weeks), only three studies met our criteria for quality assessment, and all had a high risk of bias. As predicted by the 2006 CHEST Cough Guidelines, the most common causes were respiratory infections, most likely of viral cause, followed by exacerbations of underlying diseases such as asthma and COPD and pneumonia. The subjects resided on three continents: North America, Europe, and Asia. With respect to subacute cough (duration, 3-8 weeks), only two studies met our criteria for quality assessment, and both had a high risk of bias. As predicted by the 2006 guidelines, the most common causes were postinfectious cough and exacerbation of underlying diseases such as asthma, COPD, and upper airway cough syndrome (UACS). The subjects resided in countries in Asia. With respect to chronic cough (> 8 weeks), 11 studies met our criteria for quality assessment, and all had a high risk of bias. As predicted by the 2006 guidelines, the most common causes were UACS from rhinosinus conditions, asthma, gastroesophageal reflux disease, nonasthmatic eosinophilic bronchitis, combinations of these four conditions, and, less commonly, a variety of miscellaneous conditions and atopic cough in Asian countries. The subjects resided on four continents: North America, South America, Europe, and Asia.

CONCLUSIONS

Although the quality of evidence was low, the published literature since 2006 suggests that CHEST's 2006 Cough Guidelines and management algorithms for acute, subacute, and chronic cough in adults appeared useful in diagnosing and treating patients with cough around the globe. These same algorithms have been updated to reflect the advances in cough management as of 2017.

Change in Psychological, Physiological, and Situational Factors in Adults After Treatment of Chronic Cough

BACKGROUND

We hypothesized that addressing anxiety and depressive mood disorders will improve chronic cough severity and cough quality of life (CQOL).

METHODS

Major tenets of the theory of unpleasant symptoms were examined in a longitudinal observational study of consecutive adults with cough of > 8 weeks' duration treated in our cough clinic. At baseline and 3 and 6 months, subjects completed 3 Punum Ladders rating cough severity, the CQOL Questionnaire, the Depression, Anxiety, and Stress Scales-21, and the Duke Functional Social Support Questionnaire. Cross-sectional baseline and longitudinal regression analyses were conducted.

RESULTS

Eighty subjects (55 women) with a mean age of 58.5 ± 11.1 years and a cough duration of 86.0 ± 123.7 months were enrolled. At baseline, worse cough severity was significantly associated with less education and worse ability to speak bothered by cough and the urge to cough. Worse CQOL was significantly associated with worse depression symptoms, urinary incontinence, and ability to speak; use of self-prescribed remedies; and younger age. Significant improvements in depression and stress symptoms occurred at 3 and 6 months. Anxiety symptoms improved, particularly in the first 3 months. Improvement in cough severity was significantly associated with less education, male sex, and improvement in ability to speak and urge to cough. Improvement in CQOL was significantly associated with improvement in urinary incontinence, urge to cough, anxiety symptoms, and use of self-prescribed remedies.

CONCLUSIONS

Using the theory of unpleasant symptoms, we have come to appreciate that managing psychological, physiological, and situational factors in addition to focusing on identifying the cause of cough is important to maximize improvement in CQOL.

Chronic cough: clinical characteristics and etiologies of 510 cases

BACKGROUND/AIM

To investigate the clinical features and underlying etiologies of chronic cough (CC).

MATERIALS AND METHODS

Five hundred and ten CC patients were enrolled. The phases, characteristics and associated clinical manifestations of CC among the gastroesophageal reflux cough (GERC), cough-variant asthma (CVA), and upper airway cough syndrome (UACS) groups were compared, and the diagnostic values of each group were evaluated by multiple regression analysis.

RESULTS

In the 510 patients, 404 had CC with single etiology-GERC (n = 175), CVA (n = 134), and UACS (n = 95). The characteristic features of GERC included gastric acid backflow symptoms such as sour-tasting regurgitation, heartburn, endoscopic esophagitis, poststimulation cough, frequent throat clearing, daytime mono-cough, and feelings of heaviness and pain in the chest. Patients with CVA typically exhibited sensitivity to smog and other irritants; the cough occurred mostly at night, and was associated with positive bronchodilator and provocation test results. The typical features of UACS included a history and/or symptoms of rhinitis, retropharyngeal postnasal drip, and wet cough occurring mostly during the daytime. The diagnostic specificities of above factors were >70%.

CONCLUSION

The most common causes of CC include GERC, CVA, and UACS, and their diagnosis is based on the characteristics of the underlying disease.

Chronic Cough Due to Gastroesophageal Reflux in Adults: CHEST Guideline and Expert Panel Report

BACKGROUND

We updated the 2006 ACCP clinical practice guidelines for management of reflux-cough syndrome.

METHODS

Two population, intervention, comparison, outcome (PICO) questions were addressed by systematic review: (1) Can therapy for gastroesophageal reflux improve or eliminate cough in adults with chronic and persistently troublesome cough? and (2) Are there minimal clinical criteria to guide practice in determining that chronic cough is likely to respond to therapy for gastroesophageal reflux?

RESULTS

We found no high-quality studies pertinent to either question. From available randomized controlled trials (RCTs) addressing question #1, we concluded that (1) there was a strong placebo effect for cough improvement; (2) studies including diet modification and weight loss had better cough outcomes; (3) although lifestyle modifications and weight reduction may be beneficial in suspected reflux-cough syndrome, proton pump inhibitors (PPIs) demonstrated no benefit when used in isolation; and (4) because of potential carryover effect, crossover studies using PPIs should be avoided. For question #2, we concluded from the available observational trials that (1) an algorithmic approach to management resolved chronic cough in 82% to 100% of instances; (2) cough variant asthma and upper airway cough syndrome (UACS) (previously referred to as postnasal drip syndrome) from rhinosinus conditions were the most commonly reported causes; and (3) the reported prevalence of reflux-cough syndrome varied widely.

CONCLUSIONS

The panelists (1) endorsed the use of a diagnostic/therapeutic algorithm addressing causes of common cough, including symptomatic reflux; (2) advised that although lifestyle modifications and weight reduction may be beneficial in suspected reflux-cough syndrome, PPIs demonstrated no benefit when used in isolation; and (3) suggested that physiological testing be reserved for refractory patients being considered for antireflux surgery or for those in whom there is strong clinical suspicion warranting diagnostic testing.

Occupational and Environmental Contributions to Chronic Cough in Adults: Chest Expert Panel Report

BACKGROUND

In response to occupational and environmental exposures, cough can be an isolated symptom reflecting exposure to an irritant with little physiological consequence, or it can be a manifestation of more significant disease. This document reviews occupational and environmental contributions to chronic cough in adults, focusing on aspects not previously covered in the 2006 ACCP Cough Guideline or our more recent systematic review, and suggests an approach to investigation of these factors when suspected.

METHODS

MEDLINE and TOXLINE literature searches were supplemented by articles identified by the cough panel occupational and environmental subgroup members, to identify occupational and environmental aspects of chronic cough not previously covered in the 2006 ACCP Cough Guideline. Based on the literature reviews and the Delphi methodology, the cough panel occupational and environmental subgroup developed guideline suggestions that were approved after review and voting by the full cough panel.

RESULTS

The literature review identified relevant articles regarding: mechanisms; allergic environmental causes; chronic cough and the recreational and involuntary inhalation of tobacco and marijuana smoke; nonallergic environmental triggers; laryngeal syndromes; and occupational diseases and exposures. Consensus-based statements were developed for the approach to diagnosis due to a lack of strong evidence from published literature.

CONCLUSIONS

Despite increased understanding of cough related to occupational and environmental triggers, there remains a gap between the recommended assessment of occupational and environmental causes of cough and the reported systematic assessment of these factors. There is a need for further documentation of occupational and environmental causes of cough in the future.

Evidence-based Evaluation and Management of Chronic Cough

Chronic cough is common and has a significant impact on the wellbeing of patients and the use and cost of health care services. Traditionally the approach to chronic cough in patients who are nonsmokers and are not taking an angiotensin-converting enzyme inhibitor has focused on the diagnosis and management of the upper airway cough syndrome, asthma, and reflux disease. The evaluation of patients with chronic cough frequently involves trials of empiric therapy for these 3 conditions. Chronic cough may be perpetuated by abnormalities of the cough reflex and sensitization of its afferent and central components.

Chronic cough and a normal chest X-ray - a simple systematic approach to exclude common causes before referral to secondary care: a retrospective cohort study

Chronic cough is common in the community and can cause significant morbidity. It is not clear how closely treatment guidelines are used in general practice, or how often specialist referral is indicated. We aimed to assess the management of chronic cough in primary care before referral to a cough clinic, and to assess the outcome of managing chronic cough with an approach of simple investigation and empirical treatment trials. Data were extracted from the records of all patients attending a district general hospital respiratory clinic over a two-year period with isolated chronic cough lasting ⩾8 weeks. The clinic assessed symptoms with a cough-severity visual analogue scale and the Leicester Cough Questionnaire. Among 266 patients, the most frequent diagnoses were asthma (29%), gastro-oesophageal reflux (22%) and angiotensin-converting enzyme inhibitor use (14%). In all, 12% had unexplained chronic cough. Common diagnoses had often not been excluded in primary care: only 21% had undergone spirometry, 86% had undergone chest radiography and attempts to exclude asthma with corticosteroids had been made only in 39%. In the clinic few investigations were conducted that were not available in primary care. Substantial improvements in symptoms occurred with a median (interquartile range) total of 2 (2–3) clinic visits. We estimated that 87% of patients could have been managed solely in primary care; we did not identify distinguishing characteristics among this group. Most cases of chronic cough referred to secondary care could be managed with a simple and systematic approach, which is potentially transferrable to a community setting.

Treatment of Unexplained Chronic Cough: CHEST Guideline and Expert Panel Report

BACKGROUND

Unexplained chronic cough (UCC) causes significant impairments in quality of life. Effective assessment and treatment approaches are needed for UCC.

METHODS

This systematic review of randomized controlled trials (RCTs) asked: What is the efficacy of treatment compared with usual care for cough severity, cough frequency, and cough-related quality of life in patients with UCC? Studies of adults and adolescents aged > 12 years with a chronic cough of > 8 weeks' duration that was unexplained after systematic investigation and treatment were included and assessed for relevance and quality. Based on the systematic review, guideline suggestions were developed and voted on by using the American College of Chest Physicians organization methodology.

RESULTS

Eleven RCTs and five systematic reviews were included. The 11 RCTs reported data on 570 participants with chronic cough who received a variety of interventions. Study quality was high in 10 RCTs. The studies used an assortment of descriptors and assessments to identify UCC. Although gabapentin and morphine exhibited positive effects on cough-related quality of life, only gabapentin was supported as a treatment recommendation. Studies of inhaled corticosteroids (ICS) were affected by intervention fidelity bias; when this factor was addressed, ICS were found to be ineffective for UCC. Esomeprazole was ineffective for UCC without features of gastroesophageal acid reflux. Studies addressing nonacid gastroesophageal reflux disease were not identified. A multimodality speech pathology intervention improved cough severity.

CONCLUSIONS

The evidence supporting the diagnosis and management of UCC is limited. UCC requires further study to establish agreed terminology and the optimal methods of investigation using established criteria for intervention fidelity. Speech pathology-based cough suppression is suggested as a treatment option for UCC. This guideline presents suggestions for diagnosis and treatment based on the best available evidence and identifies gaps in our knowledge as well as areas for future research.