Characteristics and difference of respiratory diseases in Korean adults aged ≥40 years: A cross‐sectional study

PURPOSE: National big data pertaining to the status of common respiratory diseases is essential to devising appropriate policies to promote proper treatment and prevention of respiratory diseases amid the prolonged coronavirus disease 2019 (COVID‐19) pandemic. The aim of this study is to investigate the prevalence of common respiratory diseases and their association with sociodemographic characteristics, comorbidities, and medical history using 11 years (2008–2018) of the Korea National Health and Nutrition Examination Survey (KNHANES) data, ultimately to present foundational data for policy decision making and disease prevention measures. METHODS: Among the participants of the KNHANES survey (2008–2018), 93 028 adults aged ≥40 years who underwent a lung function test were included in this cross‐sectional study. The participants were divided into four groups: Asthma, chronic obstructive pulmonary disease (COPD), asthma + COPD, and no respiratory disease. Their data were analyzed for demographic factors, health behavior, and disease‐related factors. Multiple logistic regression was used to calculate the odds ratio (OR) adjusted for sex, age, household income, educational level, occupation, body mass index (BMI), smoking status, alcohol consumption, physical activity, and comorbidities. RESULTS: Of all participants, 1.83%, 12.63%, and 1.27% had only asthma, only COPD, and asthma + COPD, respectively. With respect to the patients with asthma who also had asthma + COPD, the OR of asthma + COPD was 5.272 in underweight patients and 6.479 in patients aged ≥70 years. Meanwhile, a high association between COPD and asthma + COPD was found in female patients, whereas asthma was more highly associated with asthma + COPD in male patients. CONCLUSION: The study confirmed that old age, sex, smoking status, BMI, previous history of atopic dermatitis, and lung cancer were independent risk factors for asthma, COPD, and asthma + COPD. The present study demonstrated the need for a multidisciplinary integrative approach to respiratory diseases, and the findings could be used for developing policies for the treatment of COVID‐19 and respiratory diseases and the prevention of infectious diseases.