Patient-reported experiences with refractory or unexplained chronic cough: a qualitative analysis

Development and validation of a nomogram for predicting cough variant asthma diagnosis

BACKGROUND

Cough variant asthma (CVA) is a specific type of asthma characterized by chronic cough as the sole or predominant symptom. Accurate diagnosis is crucial for effective treatment, yet bronchial provocation test is not always feasible in clinical settings. To identify independent predictors of CVA diagnosis, we developed a nomogram for predicting CVA. Univariate and multivariate logistic regression analyses were employed to construct the model, and the accuracy and consistency of the prediction model were subsequently validated.

METHODS

We conducted a retrospective review of clinical data from 241 outpatients with chronic cough (≥ 8 weeks) who underwent bronchial provocation test at our hospital between January 2018 and December 2021. Patients were categorized into CVA group and Non-CVA group based on diagnostic criteria. Univariate analysis (chi-square and t-tests) was performed, followed by multivariate logistic regression to identify independent predictors. A nomogram was constructed using these predictors and validated using Bootstrap resampling (B = 200) to calculate the C-index. Additionally, receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were employed to assess the model's accuracy.

RESULTS

Of the 241 outpatients, 156 (64.7%) were diagnosed with CVA. Multivariate analysis identified several independent predictors of CVA, including cough triggered by cold air (OR = 12.493, P = 0.019), exposure to pungent odors (OR = 3.969, P = 0.002), cough phasing (OR = 4.515, P < 0.001), history of allergic rhinitis (OR = 3.231, P = 0.018), and the percentage of the predicted value of maximum mid-expiratory flow (MMEF%pred) (OR = 0.981, P = 0.039) were independent predictors of CVA. The nomogram demonstrated good discrimination (AUC = 0.829) and calibration, with a sensitivity of 75.3% and specificity of 77.6% at the optimal cutoff. The C-index was 0.920, indicating excellent model performance.

CONCLUSIONS

We successfully developed and validated a user-friendly nomogram that accurately predicted CVA diagnosis based on clinical characteristics and pulmonary function test. This nomogram model could assist clinicians in diagnosing CVA, especially in patients without bronchial provocation test or with contraindications to bronchial provocation test.

The Relationship Between Self-Reported Nocturnal Cough Symptoms and Acoustic Cough Monitoring

OBJECTIVE

This pilot investigation explored the relationship between self-reported clinical cough symptoms and objective acoustic cough data in individuals with nocturnal chronic cough.

METHODS

Ten participants diagnosed with chronic cough with a nocturnal component underwent two study sessions, approximately 1 week apart. Participants completed questionnaires regarding cough severity and their perceptions of using a smartphone application (app) to audio record cough. Between sessions, participants utilized the continuous audio recorder while sleeping. The relationship between the number of coughs captured at night and the self-reported impact of cough awakening during sleep were analyzed.

RESULTS

We found strong correlations (ρ = -0.78, -0.87) between formalized Leicester Cough Questionnaire scores and acoustically determined cough frequency. However, there were large differences between the average number of self-reported cough awakening events (0-3) and the number of acoustically recorded coughs (0-639). While users expressed comfort with recording and sharing acoustic data (4.8/5 Likert rating), concerns over confidentiality in daytime use were noted (4.1/5).

CONCLUSION

Formalized cough questionnaires provide insight into chronic cough at night but may fall short in quantifying the shear frequency of coughs patients are experiencing. Although continuous audio recordings via smartphone emerged as a comfortable means for patients to supply quantifiable data regarding the impact of chronic cough during sleep, future endeavors in cough acoustic monitoring should prioritize privacy considerations for daytime use and work to share information with health care providers.

Current opinion in refractory and/or unexplained chronic cough

PURPOSE OF REVIEW

Otolaryngologists are vital to successfully managing chronic cough in adults. This review presents updates regarding rapidly evolving concepts in chronic cough.

RECENT FINDINGS

Significant growth is occurring in chronic cough research, strengthening the evidence of its major psychosocial impacts. Elucidation of the neural underpinnings of normal and abnormal cough within both the peripheral and central nervous systems highlight the previously underappreciated complexity of cough. Recent clinical practice recommendations emphasize personalized treatment approaches through addressing treatable traits of chronic cough. Investigations are ongoing to better distinguish chronic cough subgroups, and multiple types of important clinical outcome measures are being characterized. Newer research about chronic cough treatment encompasses pharmacologic and nonpharmacologic interventions, including oral and inhaled medications, superior laryngeal nerve blocks, and behavioral therapy.

SUMMARY

As knowledge about chronic cough in adults continues to expand in both research and clinical practice, otolaryngologists can continue to raise awareness of the role of the larynx in cough and promote ongoing multidisciplinary collaborations. In the coming years, more pharmacologic options and personalized treatment approaches will likely emerge for chronic cough.

Cough Reflex Hypersensitivity as a Key Treatable Trait

Cough reflex hypersensitivity is emerging as a key treatable trait in chronic cough and other cough-associated respiratory conditions. This review examines the neurological basis of cough, highlighting the complex interplay between peripheral and central mechanisms. The concept of cough hypersensitivity aims to address unmet clinical needs by recognizing chronic cough as a distinct disorder rather than merely a symptom. Evidence from clinical trials supports cough hypersensitivity as a treatable trait in chronic cough, with opiates, gabapentinoids, and novel P2X3 antagonists showing efficacy. Cough hypersensitivity is also relevant in conditions presenting with persistent cough, such as asthma, bronchiectasis, and idiopathic pulmonary fibrosis, though more research is needed. Recognizing cough reflex hypersensitivity as a treatable trait offers new avenues for management, particularly for patients with persistent cough despite etiology-targeted therapies. We propose redefining chronic cough as a distinct disease entity in which cough hypersensitivity is a common feature and key therapeutic target, potentially leading to better patient care and the development of novel therapies.

Content validity of the Leicester Cough Questionnaire in adults with refractory or unexplained chronic cough: a qualitative interview study

BACKGROUND

Chronic cough, a cough lasting >8 weeks, includes refractory chronic cough (RCC) and unexplained chronic cough (UCC). Patient-reported outcome (PRO) measures are needed to better understand chronic cough impacts that matter most to patients. The 19-item Leicester Cough Questionnaire (LCQ), an existing PRO measure of chronic cough, assesses impacts of cough across physical, psychological, and social domains. However, the content validity of the LCQ evaluating these concepts in patients with RCC/UCC had not been established.

OBJECTIVES

To evaluate the content validity of the LCQ in patients with RCC/UCC.

DESIGN

A cross-sectional, qualitative interview study.

METHODS

First, previously completed qualitative interview results in adults with RCC/UCC (N = 30) were evaluated and mapped to LCQ concepts. Next, a clinical cough expert reviewed each LCQ item and assessed the salience of its concepts for patients with RCC/UCC. Finally, semistructured interviews-including both concept elicitation and cognitive debriefing-were conducted in adults with RCC/UCC (N = 20) to elicit a comprehensive set of participant experiences and to assess the appropriateness of using the LCQ in this population.

RESULTS

Concepts reported in the past and present qualitative interviews were included across all LCQ items, and most impacts reported to be the "most bothersome" were assessed in the LCQ. In the current study, all participants indicated that reduced cough frequency would be an important treatment target. During cognitive debriefing, each LCQ item was endorsed by ⩾70% of participants. Additionally, participants were generally able to understand, recall, and select a response for each LCQ item. All participants and the clinical expert indicated that the LCQ was appropriate and assessed the impacts most relevant to patients with RCC/UCC.

CONCLUSION

Our findings support the content validity of the LCQ and demonstrate that this measure is fit-for-purpose and includes important cough impacts in adults with RCC/UCC.