title: Seasonal Patterns of Asthma in Children and Adolescents Presenting at Emergency Departments in Korea.
abstract: OBJECTIVE
  Seasonal variations in asthma-related hospitalizations and emergency department visits have long been recognized. This study aimed to investigate the seasonal patterns of asthma in children and adolescents who presented at emergency departments in Korea.
  
  
  METHODS
  We analyzed the National Emergency Department Information System records from 117 emergency departments in Korea that comprised all of the patients with asthma who were aged 3-18 years and who presented at the emergency departments from 2007 to 2012. The children and adolescents were divided into 3 groups based on their ages, namely, 3-6 years, 7-12 years, and 13-18 years. The data were tabulated, and graphs were created to show the seasonal trends in the monthly numbers of emergency department visits as a consequence of asthma.
  
  
  RESULTS
  A total of 41,128 subjects were identified, and the male-to-female ratio was 1:0.5. General ward admissions comprised 42.6% (n=17,524 patients) of the emergency department visits, and intensive care unit admissions comprised 0.8% (n=335 patients) of the emergency department visits. The monthly numbers of emergency department visits for asthma varied according to the season, with high peaks during fall, which was from September to November, and low levels in summer, which was from June to August.
  
  
  CONCLUSIONS
  Important differences in the seasonal patterns of emergency department visits for asthma were evident in children and adolescents. Identifying seasonal trends in asthma-related emergency department visits may help determine the causes and reduce the likelihood of asthma exacerbation.
authors.affiliation: Department of Pediatrics, National Medical Center, Seoul, Korea.
authors.forename: Youn Kyoung
authors.initials: YK
authors.lastname: Won
authors.affiliation: Department of Pediatrics, National Medical Center, Seoul, Korea.
authors.forename: Tae Ho
authors.initials: TH
authors.lastname: Hwang
authors.affiliation: Department of Pediatrics, Sun General Hospital, Daejeon, Korea.
authors.forename: Eui Jung
authors.initials: EJ
authors.lastname: Roh
authors.affiliation: Department of Pediatrics, National Medical Center, Seoul, Korea. ehchung@nmc.or.kr.
authors.forename: Eun Hee
authors.initials: EH
authors.lastname: Chung
keywords: Asthma; adolescent; child; emergency department; epidemiology; seasons