title: The effect of Asian dust on asthma by socioeconomic status using national health insurance claims data in Korea.
abstract: BACKGROUND
  Asian dust events are associated with increased asthma incidence, asthma exacerbation, decreased lung function and increased risk for hospitalization.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the effect of Asian dust events on asthma exacerbation by socioeconomic status using national health insurance claims data.
  
  
  METHODS
  A case-crossover design was used to analyze asthma-related national health insurance claims, air pollutant and climate data from 2007 to 2013 in Seoul and Incheon, Korea. We stratified our analysis by socioeconomic status (health insurance versus medical aid subscribers) and calculated the maximum air pollutant levels and average climate values per day. The number of asthma-related visits to medical institutions per day was compared between "event" and "control" days.
  
  
  RESULTS
  Compared with "control days", the average number of asthma-related visits to medical institutions decreased on "event" days and increased 1-5 d thereafter. The number of visits by health insurance subscribers also decreased on "event" days and increased 1-5 d thereafter, while the number of visits by medical aid subscribers did not change on "event" days but increased 1-4 d thereafter.
  
  
  CONCLUSIONS
  Our study confirms that Asian dust events result in an increased number of asthma-related visits to medical institutions. This effect differed by socioeconomic status.
authors.affiliation: a Environmental Health Center for Allergic Disease, INHA University Hospital , Incheon , Korea .|b Department of Biostatistics , Korea University , Seoul , Korea .
authors.forename: Yoon-Sung
authors.initials: YS
authors.lastname: Park
authors.affiliation: a Environmental Health Center for Allergic Disease, INHA University Hospital , Incheon , Korea .|c Department of Pediatrics , College of Medicine, INHA University , Incheon , Korea , and.
authors.forename: Jeong-Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: a Environmental Health Center for Allergic Disease, INHA University Hospital , Incheon , Korea .
authors.forename: Hae-Ji
authors.initials: HJ
authors.lastname: Jang
authors.affiliation: d National Health Insurance Service , Seoul , Korea.
authors.forename: Yoon-Hee
authors.initials: YH
authors.lastname: Tae
authors.affiliation: a Environmental Health Center for Allergic Disease, INHA University Hospital , Incheon , Korea .|c Department of Pediatrics , College of Medicine, INHA University , Incheon , Korea , and.
authors.forename: Dae Hyun
authors.initials: DH
authors.lastname: Lim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D001208:Asia; D001249:Asthma / Q000453:epidemiology*; D002248:Carbon Monoxide / Q000032:analysis / Q000633:toxicity; D002648:Child; D016208:Databases, Factual; D004391:Dust; D006268:Health Facilities / Q000706:statistics & numerical data*; D006801:Humans; D008875:Middle Aged; D009313:National Health Programs; D009585:Nitrogen Dioxide / Q000032:analysis / Q000633:toxicity; D010126:Ozone / Q000032:analysis / Q000633:toxicity; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity; D012923:Social Class; D013458:Sulfur Dioxide / Q000032:analysis / Q000633:toxicity; D014887:Weather; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D004391:Dust; D052638:Particulate Matter; D013458:Sulfur Dioxide; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide
keywords: Asian dust; asthma; health insurance claim