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

Abstract

BackgroundCough 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.ObjectiveThe aim of this study was to establish items and domains that would inform development of a new cough severity instrument.MethodsThree 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.ResultsThe 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).ConclusionsConsensus 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 “vicious circle” of chronic cough: the patient experience – qualitative synthesis

“…To ensure no literature had unintentionally been omitted during the search strategy, both forward and backward citation searching of the 5 studies [21][22][23][24][25][26] was undertaken, yielding no further results. Daily email alerts were set up, with links to studies that met the search strategy via all four of the academic bibliographic databases, allowing 1 contemporary addition [21].…”

“…This resulting six studies [21][22][23][24][25][26] underwent critical appraisal with the use of the Critical Appraisal Skills Programme Qualitative Research Checklist (CASP (Critical Appraisal Skills Programme), 2018). (Supplementary File 3).…”

“…Studies were published between 2009 and 2022. Data reflects the views of individuals from 4 countries, United States of America (n=2) [23,25], Canada (n=-1) [26], United Kingdom (n=1) [24] and Japan (n=1) [21]. It was not possible to determine the location of participants in one of the studies [22] as data was collected via online forums.…”

Chronic cough—the limitation and advances in assessment techniques

“… Other tools: McMaster Cough Severity Questionnaire (a current conceptual framework for measuring cough severity in RCC/UCC patients) ( 186 ). C2, the first administered concentration of tussive stimuli causing two coughs; C5, the first administered concentration of tussive stimuli causing five coughs; VAS, Visual Analogue Scale; LCQ, Leicester Cough Questionnaire; CSD, Cough Severity Diary; NA, not applicable; ICC, intraclass correlation coefficient; ES, effect size; CC, chronic cough; COPD, chronic obstructive pulmonary disease; ILD, interstitial lung disease; K-CSS, Korean Cough Symptom Score; VAS, Visual Analogue Scale; sCSS, simplified cough symptom score; CLCQ, Cough Quality of Life Questionnaire; CSI, Cough Severity Index; MCI, Multidimensional Cough Index; CET, Cough Evaluation Test; MCID, minimum clinically important difference; RCC, refractory chronic cough; UCC, unexplained chronic cough.…”

“…The McMaster cough severity questionnaire is a newly developed cough symptom severity instrument for RCC patients and provided 43 items addressing the following domains: urge-to-cough sensations (subdomains: frequency and intensity) and cough symptom (subdomains: frequency, control, bout duration, intensity, and associated features/sequelae) ( 186 , 195 ). This currently is a conceptual framework.…”