2018 Section 6 - Laryngology, Voice Disorders, and Bronchoesophalogy

lifestyle, environment, occupational exposure, and socioeconomic status). Finally, we used a cross-sectional study design to identify the risk factors for chronic cough, and although many of these risk factors have previously been described in reports from specialized clinics and are included in the clinical guidelines, 8-10 the identi fi ed risk factors need to be con fi rmed using a longitudinal study design. In conclusion, the prevalence of chronic cough was 4% overall and 3% in never smokers, 4% in former smokers, and 8% in current smokers. At the level of the individual, the top-ranked chronic cough risk factors based on the magnitude of the ORs were bronchiectasis, asthma, and gastroesophageal re fl ux disease in never- smokers; bronchiectasis, asthma, and occupational exposure to dust/fumes in former smokers; and air fl ow limitation in current smokers. At the level of the community, the top-ranked chronic cough risk factors based on the magnitude of the PARs were female sex, asthma, and gastroesophageal re fl ux disease in never- smokers; abdominal obesity, low income, and asthma in former smokers; and air fl ow limitation in current smokers. Importantly, most of the identi fi ed risk factors are potentially modi fi able. Because chronic cough risk factors differ at individual and community levels, and by smoking status, strategies to prevent and treat modi fi able chronic cough risk factors should be tailored accordingly.

and women regarding the Leicester Cough Questionnaire. 42 In the present study, the scores were lower for current smokers, and there were no differences between never smokers and former smokers with chronic cough, indicating that smoking worsens the health impact of an ongoing cough. Strengths of this study include a large sample randomly selected from the general population with a substantial number of individuals with chronic cough and information on the severity of chronic cough, measured by using a validated instrument, the Leicester Cough Questionnaire. 45 A potential limitation is that we only could register previously diagnosed conditions as potential risk factors for chronic cough. This may work well regarding gastroesophageal re fl ux disease, where we had information on both previous contact with the health system for this diagnosis and also on the use of speci fi c medications for this condition. However, regarding bronchiectasis, a disease which is known to be underdiagnosed, our approach will lead to an underestimation of the importance of this condition for the risk of chronic cough. The diagnosis of bronchiectasis in the national Danish Patient Registry has not been validated before. Another potential limitation regarding generalization of our fi ndings is that risk factors for chronic cough may differ from developed to undeveloped countries (eg, because of differences in

Acknowledgments Author contributions: M. D. takes responsibility for the content of the

fees from Nycomed, personal fees from P fi zer, and personal fees from Mundipharma, outside the submitted work. None declared (B. G. N., L. C. L., S. A., M.D.). Role of sponsors: The sponsors did not participate in the design and conduct of the study; collection, management, analysis, or interpretation of the data; in preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. Additional information: The e-Appendix and e-Tables can be found in the Supplemental Materials section of the online article. References 1. Chung KF, Pavord ID. Prevalence, pathogenesis, and causes of chronic cough. Lancet . 2008;371(9621):1364-1374 . 2. Song WJ, Chang YS, Faruqi S, et al. The global epidemiology of chronic cough in adults: a systematic review and meta-analysis. Eur Respir J . 2015;45(5): 1479-1481 . 3. Song WJ, Chang YS, Faruqi S, et al. De fi ning chronic cough: a systematic

review of the epidemiological literature. Allergy Asthma Immunol Res . 2016;8(2): 146-155 . 4. Desalu OO, Salami AK, Fawibe AE. Prevalence of cough among adults in an urban community in Nigeria. West Afr J Med . 2011;30(5):337-341 . 5. Ford AC, Forman D, Moayyedi P, Morice AH. Cough in the community: a cross sectional survey and the relationship to gastrointestinal symptoms. Thorax . 2006;61(11):975-979 . 6. Fujimura M. Frequency of persistent cough and trends in seeking medical care and treatment-results of an internet survey. Allergol Int . 2012;61(4): 573-581 . 7. Gibson PG, Vertigan AE. Management of chronic refractory cough. BMJ . 2015;351: h5590 . 8. Irwin RS, Baumann MH, Bolser DC, et al. Diagnosis and management of cough executive summary: ACCP evidence- based clinical practice guidelines. Chest . 2006;129(1 suppl):1S-23S . 9. Morice AH, Fontana GA, Sovijarvi AR, et al. The diagnosis and management of

manuscript, including the data and analysis. Y. Ç. and M. D. had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analyses. Y. Ç., B. G. N., L. C. L., S. A., P. L., and M. D. contributed to study concept and design. Y. Ç., B. G. N., L. C. L., S. A., P. L., and M. D. contributed to acquisition, analyses, or interpretation of data. Y. Ç. drafted the manuscript. Y. Ç., B. G. N., L. C. L., S. A., P. L., and M. D. provided critical revision of the manuscript for important intellectual content. Y. Ç. and M. D. provided statistical analyses. B. G. N. and M. D. provided study supervision. Financial/non fi nancial disclosures: The authors have reported to CHEST the following: Y. Ç. reports personal fees from Boehringer Ingelheim outside the submitted work. P. L. reports grants and personal fees from Almirall, grants and personal fees from Boehringer Ingelheim, personal fees from Astra Zeneca, personal fees from Novartis, grants and personal fees from GSK, personal

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