title: [Association between ambient temperature and hospital emergency room visits for cardiovascular diseases: a case-crossover study].
abstract: OBJECTIVE
  To explore the association between ambient average temperature and hospital emergency room visits for cardiovascular diseases (International Classification of Diseases, Tenth Vision ICD-10: I00 - I99) in Beijing, China.
  
  
  METHODS
  Data was collected on daily hospital emergency room visits for cardiovascular diseases from Peking University Third Hospital, including meteorological data (daily average temperature, relative humidity, wind speed, and atmospheric pressure) from the China Meteorological Data Sharing Service System, and on air pollution from the Beijing Municipal Environmental Monitoring Center. Time-stratified case-crossover design was used to analyze data on 4 seasons.
  
  
  RESULTS
  After adjusting data on air pollution, 1 degree ( degrees C) increase of ambient average temperature would associate with the emergency room visits of odds ratio (ORs) as 1.282 (95%CI: 1.250 - 1.315), 1.027 (95%CI: 1.001 - 1.055), 0.661 (95%CI: 0.637 - 0.687), and 0.960 (95%CI: 0.937 - 0.984) in spring, summer, autumn, and winter respectively. After controlling the influence of relative humidity, wind speed, and atmospheric pressure, 1 degrees C increase in the ambient average temperature would be associated with the emergency room visits on ORs value as 1.423 (95%CI: 1.377 - 1.471), 1.082 (95%CI: 1.041 - 1.124), 0.633 (95%CI: 0.607 - 0.660) and 0.971 (95%CI: 0.944 - 1.000) in spring, summer, autumn, and winter respectively.
  
  
  CONCLUSIONS
  These data on outcomes suggested that the elevated level of ambient temperature would increase the hospital emergency room visits for cardiovascular diseases in spring and summer while the elevated level of ambient temperature would decrease the hospital emergency room visits for the cardiovascular diseases in autumn and winter, suggesting that patients with cardiovascular diseases should pay attention to the climate change.
authors.affiliation: Department of Occupational and Environmental Health, School of Public Health, Peking University, Beijing 100191, China.
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Guo
authors.forename: Jia-Jia
authors.initials: JJ
authors.lastname: Wang
authors.forename: Guo-Xing
authors.initials: GX
authors.lastname: Li
authors.forename: Ya-An
authors.initials: YA
authors.lastname: Zheng
authors.forename: Wichmann
authors.initials: W
authors.lastname: He
authors.forename: Xiao-Chuan
authors.initials: XC
authors.lastname: Pan
mesh_terms: D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002681:China; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006785:Hospitals, University; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D016017:Odds Ratio; D012621:Seasons; D013696:Temperature