Defining Chronic Cough: A Systematic Review of the Epidemiological Literature

• Published in: Allergy, asthma & immunology research 2016, Asthma & Immunology Research, 8(2), , pp.146-155
• Main Authors: Song, Woo Jung, Chang, Yoon Seok, Faruqi, Shoaib, Kang, Min Koo, Kim, Ju Young, Kang, Min Gyu, Kim, Sujeong, Jo, Eun Jung, Lee, Seung Eun, Kim, Min Hye, Plevkova, Jana, Park, Heung Woo, Cho, Sang Heon, Morice, Alyn H
• Format: Article
• Language: English
• Subjects: Original; 내과학
• ISSN: 2092-7355; 2092-7363
• DOI: 10.4168/aair.2016.8.2.146

Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics. A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions. A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as 'cough ≥3 months' duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I²=96%, P