Increased Prevalence of Self-Reported Asthma Among Korean Adults: An Analysis of KNHANES I and IV Data

Asthma is one of the most common chronic conditions. Knowing the longitudinal trends of prevalence is important in developing health service planning and in assessing the impact of the disease. However, there have been no studies that examined current asthma prevalence trends in Korea through the analysis of nationwide surveys. Data were acquired from patients aged 20-59 years who participated in the First Korean National Health and Nutritional Examination Surveys (KNHANES), which was conducted in 1998, and in the second year of the Fourth KNHANES, which was conducted in 2008. To estimate the prevalence of asthma with age and gender standardization, we used data from the Population and Housing Census, which was conducted by Statistics Korea in 2005. The prevalence of physician-diagnosed asthma increased from 1998 to 2008 (1998: 0.7 %, 2008: 2.0 %). The prevalence of asthma medication usage also increased from 1998 to 2008 (1998: 0.3 %, 2008: 0.7 %); however, the prevalence of wheezing decreased between 1998 and 2008 (1998: 13.7 %, 2008: 6.3 %). A similar trend was observed after estimating the prevalence of asthma with age and gender standardization. Allergic rhinitis might be the reason for the increased prevalence of physician-diagnosed asthma, while the observed decrease in wheezing may be related to the decrease in smoking or the increase in the use of asthma medication. The present study showed that the prevalence of both self-reported physician-diagnosed asthma and asthma medication usage increased from 1998 to 2008 in Korea, despite a possible changing pattern of diagnosing asthma.