The widespread mechanism of chronic cough. Having said that, characteristics of chronic cough in COPD haven’t been effectively described; it may exhibit functions distinct from those of cough hypersensitivity syndrome-associated cough. As evidence to support this hypothesis, one study located that cough frequency in COPD patients is associated with sputum production, smoking, and airway inflammation, and that these aspects could appear to be additional crucial than the sensitivity of your cough reflex.two Within this regard, sputum has been rather emphasized than cough in COPD patients, and also a clinical phenotype characterized by prominent and persistent cough and sputum production for at the very least 3 months for the duration of every single of two Chroman 1 ROCK consecutive years has been defined as chronic bronchitis (CB). The CB phenotype is related with worse respiratory symptoms, greater rate of acute exacerbation of COPD (AECOPD), and worse illness influence inInternational Journal of COPD 2018:13 1793Correspondence: Deog Kyeom Kim Division of Pulmonary and Important Care Medicine, Department of Internal Medicine, seoul Metropolitan government-seoul national University Boramae Healthcare Center, seoul national University College of Medicine, 20 Boramaero-5-gil, Dongjak-gu, seoul, 156-707, republic of Korea Tel +82 2 870 2228 Fax +82 2 831 2826 email [email protected] your manuscript | www.dovepress.comDovepresshttp:dx.doi.org10.2147COPD.S2018 Koo et al. This work is published and licensed by Dove Health-related Press Restricted. The full terms of this license are obtainable at https:www.dovepress.comterms.php and incorporate the Inventive Commons Attribution Non Industrial (unported, v3.0) License (http:creativecommons.orglicensesby-nc3.0). By accessing the work you hereby accept the Terms. Non-commercial utilizes of your work are permitted without any further permission from Dove Medical Press Restricted, offered the work is properly attributed. For permission for commercial use of this function, please see paragraphs four.2 and five of our Terms (https:www.dovepress.comterms.php).Koo et alDovepressCOPD sufferers.3 However, chronic cough will not be constantly accompanied by sputum, and it may take place as single manifestation of COPD.9 The clinical effect of chronic cough on COPD outcomes has not been properly reported; for that reason, it may be essential to investigate how chronic cough affects COPD outcomes, such as top quality of life (QoL) and future danger of AECOPD, irrespective of presence or absence of sputum. The aim of our study was to recognize phenotypic variations in line with presence of chronic cough or sputum in COPD patients and evaluate the influence of chronic cough on the threat of future AECOPD.DefinitionsCOPD was defined and stratified by the International Initiative for Obstructive Lung Illness (GOLD) criteria.17 KOCOSS includes following questionnaires to define CB: 1) Do you expertise a cough most days, for at the least three months per year 2) Have you had cough for greater than two consecutive years three) Do you generate sputum most days, for a minimum of three months per year and 4) Have you had sputum for more than two consecutive years Chronic cough and sputum production have been defined making use of these queries. If patient answered “yes” to question 1, then the topic was classified as having chronic cough. If patient answered “yes” to query three, then they had been classified into group with chronic sputum. If patient answered “yes” to 1 and 3, then the topic was defined as getting CB. Sufferers who answered “I don’t know” and those who did not answer a question had been ex.