title: Extreme temperatures and out-of-hospital coronary deaths in six large Chinese cities.
abstract: BACKGROUND
  The seasonal trend of out-of-hospital coronary death (OHCD) and sudden cardiac death has been observed, but whether extreme temperature serves as a risk factor is rarely investigated. We therefore aimed to evaluate the impact of extreme temperatures on OHCDs in China. We obtained death records of 126,925 OHCDs from six large Chinese cities (Harbin, Beijing, Tianjin, Nanjing, Shanghai and Guangzhou) during the period 2009-2011.
  
  
  METHODS
  The short-term associations between extreme temperature and OHCDs were analysed with time-series methods in each city, using generalised additive Poisson regression models. We specified distributed lag non-linear models in studying the delayed effects of extreme temperature. We then applied Bayesian hierarchical models to combine the city-specific effect estimates.
  
  
  RESULTS
  The associations between extreme temperature and OHCDs were almost U-shaped or J-shaped. The pooled relative risks (RRs) of extreme cold temperatures over the lags 0-14 days comparing the 1st and 25th centile temperatures were 1.49 (95% posterior interval (PI) 1.26-1.76); the pooled RRs of extreme hot temperatures comparing the 99th and 75th centile temperatures were 1.53 (95% PI 1.27-1.84) for OHCDs. The RRs of extreme temperature on OHCD were higher if the patients with coronary heart disease were old, male and less educated.
  
  
  CONCLUSIONS
  This multicity epidemiological study suggested that both extreme cold and hot temperatures posed significant risks on OHCDs, and might have important public health implications for the prevention of OHCD or sudden cardiac death.
authors.affiliation: School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, & Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China Research Institute for the Changing Global Environment and Fudan Tyndall Centre, Fudan University, Shanghai, China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Fudan University, Shanghai, China.
authors.forename: Renjie
authors.initials: R
authors.lastname: Chen
authors.affiliation: Institute of Environmental Health and Related Product Safety, Chinese Center for Disease Control and Prevention, Beijing, China.
authors.forename: Tiantian
authors.initials: T
authors.lastname: Li
authors.affiliation: School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, & Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China Research Institute for the Changing Global Environment and Fudan Tyndall Centre, Fudan University, Shanghai, China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Fudan University, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cai
authors.affiliation: College of Environmental Sciences and Engineering, Peking University, Beijing, China.
authors.forename: Meilin
authors.initials: M
authors.lastname: Yan
authors.affiliation: School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, & Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China.
authors.forename: Zhuohui
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, & Key Lab of Health Technology Assessment of the Ministry of Health, Fudan University, Shanghai, China Research Institute for the Changing Global Environment and Fudan Tyndall Centre, Fudan University, Shanghai, China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP), Fudan University, Shanghai, China.
authors.forename: Haidong
authors.initials: H
authors.lastname: Kan
mesh_terms: D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D002681:China / Q000453:epidemiology; D055873:Extreme Cold / Q000009:adverse effects*; D055874:Extreme Heat / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality*; D014505:Urban Population
chemical_list: D000393:Air Pollutants
keywords: BIOSTATISTICS; CLIMATE CHANGE; Clinical epidemiology; Environmental epidemiology