Abstract
The global prevalence of chronic cough is highly variable, ranging from 2% to 18%. There is a lack of data on the prevalence and incidence of chronic cough in the general population. The objective of this study was to investigate the prevalence and incidence of chronic cough in a sample of Canadian adults, and how these are influenced by age, sex, smoking, respiratory symptoms, medical comorbidities and lung function.
Participants with chronic cough were identified from the Canadian Longitudinal Study on Aging (CLSA) based on self-reported daily cough in the past 12 months. This is a prospective, nationally generalisable, stratified random sample of adults aged 45–85 years at baseline recruited between 2011 and 2015, and followed-up 3 years later. The prevalence and incidence per 100 person-years are described, with adjustments for age, sex and smoking.
Of the 30 097 participants, 29 972 completed the chronic cough question at baseline and 26 701 did so at follow-up. The prevalence of chronic cough was 15.8% at baseline and 17.6% at follow-up with 10.4–17.1% variation across seven provinces included in the CLSA comprehensive sample. Prevalence increased with age and current smoking, and was higher in males (15.2%), Caucasians (14%) and those born in North America, Europe or Oceania (14%). The incidence of chronic cough adjusted for age, sex and smoking was higher in males and in underweight and obese subjects. Subjects with respiratory symptoms, airway diseases, lower forced expiratory volume in 1 s (% predicted), cardiovascular diseases, psychological disorders, diabetes and chronic pain had a higher incidence of chronic cough.
The prevalence and incidence of chronic cough is high in the CLSA sample with geographic, ethnic and gender differences, influenced by a number of medical comorbidities.
Abstract
Canada has one of the highest prevalences of chronic cough in world and it is more common in Caucasians of European descent. Ageing, smoking, sex, clinical comorbidities and lung physiology all influence the prevalence and incidence of chronic cough. https://bit.ly/3qSBkdp
Footnotes
Data availability: Data are available from the Canadian Longitudinal Study on Aging (CLSA) (www.clsa-elcv.ca) for researchers who meet the criteria for access to de-identified CLSA data.
Author contributions: I. Satia, A.J. Mayhew, K.J. Killian, P.M. O'Byrne and P. Raina contributed substantially to the study concept and design. All authors made substantial contributions to the acquisition, analysis or interpretation of data for the manuscript. I. Satia, A.J. Mayhew and N. Sohel contributed substantially to drafting the manuscript. All authors contributed to the critical revision of the manuscript for important intellectual content, final approval of the version to be published, and agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. P. Raina had full access to all of the data in the study, and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Conflict of interest: I. Satia reports grants and personal fees from Merck during the conduct of the study; and personal fees for educational talks for general practitioners from GSK and AstraZeneca, grants and personal fees from Merck Canada, an ERS Respire 3 Marie Curie Fellowship and an E.J. Moran Campbell Early Career Award, outside the submitted work.
Conflict of interest: A.J. Mayhew has nothing to disclose.
Conflict of interest: N. Sohel has nothing to disclose.
Conflict of interest: O. Kurmi has nothing to disclose.
Conflict of interest: K.J. Killian has nothing to disclose.
Conflict of interest: P.M. O'Byrne reports grants and personal fees from AstraZeneca and Medimmune, personal fees from GSK and Chiesi, and grants from Novartis, outside the submitted work.
Conflict of interest: P. Raina has nothing to disclose.
Support statement: The study was funded by Merck Canada. The study sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. I. Satia is currently supported by the E.J. Moran Campbell Early Career Award, Dept of Medicine, McMaster University. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received March 9, 2021.
- Accepted March 9, 2021.
- Copyright ©The authors 2021
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