title: The association between cold spells and pediatric outpatient visits for asthma in Shanghai, China.
abstract: BACKGROUND
  Asthma is a serious global health problem. However, few studies have investigated the relationship between cold spells and pediatric outpatient visits for asthma.
  
  
  OBJECTIVE
  To examine the association between cold spells and pediatric outpatient visits for asthma in Shanghai, China.
  
  
  METHODS
  We collected daily data on pediatric outpatient visits for asthma, mean temperature, relative humidity, and ozone from Shanghai between 1 January 2007 and 31 December 2009. We defined cold spells as four or more consecutive days with temperature below the 5(th) percentile of temperature during 2007-2009. We used a Poisson regression model to examine the impact of temperature on pediatric outpatient visits for asthma in cold seasons during 2007 and 2009. We examined the effect of cold spells on asthma compared with non-cold spell days.
  
  
  RESULTS
  There was a significant relationship between cold temperatures and pediatric outpatient visits for asthma. The cold effects on children's asthma were observed at different lags. The lower the temperatures, the higher the risk for asthma attacks among children.
  
  
  CONCLUSIONS
  Cold temperatures, particularly cold spells, significantly increase the risk of pediatric outpatient visits for asthma. The findings suggest that asthma children need to be better protected from cold effects in winter.
authors: School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
authors: Yuming
authors: Y
authors: Guo
authors: Fan
authors: F
authors: Jiang
authors: Li
authors: L
authors: Peng
authors: Jun
authors: J
authors: Zhang
authors: Fuhai
authors: F
authors: Geng
authors: Jianming
authors: J
authors: Xu
authors: Canming
authors: C
authors: Zhen
authors: Xiaoming
authors: X
authors: Shen
authors: Shilu
authors: S
authors: Tong
mesh_terms: D000293:Adolescent; D000397:Air Pollution / Q000032:analysis; D000553:Ambulatory Care / Q000706:statistics & numerical data*; D001249:Asthma / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D002681:China; D003080:Cold Temperature; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D012306:Risk; D013997:Time Factors