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

Elena Kum; Gordon H Guyatt; Caroline Munoz; Suzanne Beaudin; Shelly-Anne Li; Rayid Abdulqawi; Huda Badri; Louis-Philippe Boulet; Ruchong Chen; Peter Dicpinigaitis; Lieven Dupont; Stephen K Field; Cynthia L French; Peter G Gibson; Richard S Irwin; Paul Marsden; Lorcan McGarvey; Jaclyn A Smith; Woo-Jung Song; Paul M O'Byrne; Imran Satia

doi:10.1183/23120541.00667-2021

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

ERJ Open Res. 2022 Mar 14;8(1):00667-2021. doi: 10.1183/23120541.00667-2021. eCollection 2022 Jan.

Authors

Elena Kum¹, Gordon H Guyatt^{1

2}, Caroline Munoz², Suzanne Beaudin², Shelly-Anne Li³, Rayid Abdulqawi⁴, Huda Badri⁵, Louis-Philippe Boulet⁶, Ruchong Chen⁷, Peter Dicpinigaitis⁸, Lieven Dupont⁹, Stephen K Field¹⁰, Cynthia L French¹¹, Peter G Gibson¹², Richard S Irwin¹¹, Paul Marsden^{5

13}, Lorcan McGarvey¹⁴, Jaclyn A Smith⁵, Woo-Jung Song¹⁵, Paul M O'Byrne^{2

16}, Imran Satia^{1

2

16}

Affiliations

¹ Dept of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.
² Dept of Medicine, McMaster University, Hamilton, ON, Canada.
³ Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Toronto, ON, Canada.
⁴ King Fahad Specialist Hospital-Dammam and Dept of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
⁵ Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester, UK.
⁶ Québec Heart and Lung Institute, Laval University, Quebec City, QC, Canada.
⁷ Dept of Allergy and Clinical Immunology, State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
⁸ Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA.
⁹ Dept of Respiratory Diseases, University Hospital Leuven, Katholieke Universiteit Leuven, Leuven, Belgium.
¹⁰ Dept of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
¹¹ Division of Pulmonary, Allergy, and Critical Care Medicine, Dept of Medicine, UMass Memorial Medical Center, Worcester, MA, USA.
¹² Priority Research Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, Faculty of Health and Medicine, The University of Newcastle, Callaghan, NSW, Australia.
¹³ Wythenshawe Hospital, Manchester University, NHS Foundation Trust, Manchester, UK.
¹⁴ Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK.
¹⁵ Dept of Allergy and Clinical Immunology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
¹⁶ Firestone Institute for Respiratory Health, St Joseph's Healthcare, Hamilton, ON, Canada.

Abstract

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.