<p>Chronic Cough and Phlegm in Subjects Undergoing Comprehensive Health Examination in Japan – Survey of Chronic Obstructive Pulmonary Disease Patients Epidemiology in Japan (SCOPE-J)</p>

Abstract

Purpose: The purpose of this study was to estimate the prevalence of subjects with chronic cough and phlegm and describe their characteristics including the presence or absence of airflow limitation among the general population in Japan. Subjects and Methods: This was an observational cross-sectional survey targeting multiple regions of Japan. Subjects aged 40 years or above who were undergoing comprehensive health examination were recruited. The existence of chronic cough and phlegm, airflow limitation, and treatment for respiratory diseases were examined. Chronic cough and phlegm were defined as having both symptoms for at least 3 months of the year and for at least 2 consecutive years, or as receiving any treatment for chronic bronchitis at the time of recruitment. Airflow limitation was defined as forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) less than 0.7. Results: In a total of 22,293 subjects, 380 subjects (1.7%) had chronic cough and phlegm. Among these 380 subjects, 21.8% received treatment for a respiratory disease, and 11.6% had airflow limitation. Compared to subjects without both chronic cough and phlegm but with airflow limitation, subjects with chronic cough and phlegm without airflow limitation were younger, more likely to be current smokers (39.6%), and had higher total scores on a chronic obstructive pulmonary disease (COPD) assessment test (CAT). Scores of CAT questions 1-4 (cough, phlegm, chest tightness, breathlessness, respectively) were higher in subjects with chronic cough and phlegm regardless of airflow limitation. Conclusion: This study demonstrated that subjects identified to have chronic cough and phlegm in comprehensive health examination settings were symptomatic, while most of them did not receive any treatment for respiratory diseases and did not have airflow limitation. Screening subjects for chronic cough and phlegm in a comprehensive health examination followed by a detailed examination of screened subjects could be an effective approach for better management of chronic cough and phlegm. Smoking cessation should be included in the management, in consideration that around 40% of subjects with chronic cough and phlegm were current smokers.

Prevalence and burden of chronic cough in China: a national cross-sectional study

“…The prevalence of 3.6% in the present study is very similar to the value of 3.48% found among adults aged 40 years or older based on the same criterion reported by W on et al [ 29 ] from the Korean National Health and Nutrition Examination survey of 2010–2016 and was also similar to the 4% prevalence reported in Denmark in adults aged 20 years and older using an ≥8-week duration of chronic cough [30]. The prevalence of 3.6% in the present study was higher than the value of 1.7% among the general population aged 40 years or older reported by O mori et al [ 31 ] in Japan, in which chronic cough was defined as having both cough and phlegm for at least 3 months of the year and for at least 2 consecutive years, or as receiving any treatment for chronic bronchitis at the time of recruitment. However, the prevalence of 3.6% in the present study was far lower than the estimation of 7.9% in the global general adult population using the 3 months cut-off definition reported from a systematic review and meta-analysis by S ong et al [ 1 ] and the 16% prevalence in Northern Europe from the Respiratory Health in Northern Europe (RHINE) III cohort using a definition of chronic cough lacking a specified timeframe but described as protracted and troublesome [ 32 ].…”

<p>Associated Factors and Comorbidities of Airflow Limitation in Subjects Undergoing Comprehensive Health Examination in Japan – Survey of Chronic Obstructive Pulmonary Disease Patients Epidemiology in Japan (SCOPE- J)</p>

“…There were 962 (4.3%) subjects with airflow limitation. 1 Three-hundred eighty (1.7%) subjects had chronic cough/phlegm (including those who had received current treatment for chronic bronchitis) 2 and 400 (1.8%) subjects had received current treatment for respiratory diseases listed in the “Study design and participants” section. A total of 1520 (6.8%) subjects had at least one of the airflow limitation, chronic cough/phlegm, and currently treated respiratory diseases.…”

“…In the previous reports, we demonstrated the prevalence and characteristics of airflow limitation and chronic cough/phlegm among subjects undergoing comprehensive health examination. 1 , 2 Comprehensive health examination in Japan includes spirometry testing and provides an opportunity for collecting spirometry data along with other clinical characteristics within the general population. Typically, subjects undergoing comprehensive health examination are company employees and non-employee community residents.…”