A Delphi approach to the development of standard questionnaire to investigate asthma in Koreans

Purpose: Recently, the prevalence and disease burden of asthma have increased. Thus, the need for early diagnosis and appropriate management of asthma is emerging. However, it is difficult to identify the diagnosis, symptoms and the prevalence of asthma due to lack of reliable investigating items. The purpose of this study was to develop a standardized survey format in order to assess the prevalence of asthma in Koreans. Methods: We investigated surveys and related information that are utilized to assess asthma diagnosis and prevalence by systematic review. After that, Delphi survey was conducted on 44 Korean allergists in order to develop a standardized survey in Korea. The process consisted of 3 serial rounds across 3 age groups. Each subsequent round narrowed investigating items for the decision of standard set about asthma prevalence, current asthma, and asthma aggravation. Results: Lifetime asthma was defined as "ever doctor-diagnosed asthma" in all age groups. Current asthma was defined as "treatment for asthma during the past 12 months" in all age groups, and "doctor-diagnosed asthma during the past 12 months" was added on the >= 5-year-old and adult groups. "Wheezing ever" was defined as "wheezing at any time in the past,"and current wheeze was defined as "wheezing in the last 12 months." Asthma aggravation was defined as "visits at the emergency department or admission due to asthma attack within the last 12 months" in all age groups. Conclusion: We established applicable nationwide definitions of "lifetime asthma," "current asthma," and "asthma aggravation" in Koreans by the Delphi survey.