title: The effect of heat waves on mortality and effect modifiers in four communities of Guangdong Province, China.
abstract: BACKGROUND
  Heat waves have been reported to be associated with increased mortality; however, fewer studies have examined the effect modification by heat wave characteristics, individual characteristics and community characteristics.
  
  
  METHODS
  This study investigated the effect of extreme heat on mortality in 2 urban and 2 rural communities in Guangdong Province, China during 2006-2010. The effect of extreme heat was divided into two parts: main effect due to high temperature and added effect due to prolonged heat for several consecutive days. A distributed lag non-linear model was used to calculate the relative risk with consideration of lag days and potential confounding factors. Separate models were further fit by individual characteristics (cause of death, age and gender) and heat wave characteristics (intensity, duration and timing), and potential effect modification of community characteristics was examined using a meta-regression, such as educational levels, percentage of the elderly, Gross Regional Domestic Product (GDP).
  
  
  RESULTS
  The overall main effects (ER=8.2%, 95% CI: 3.4%, 13.2%) were greater than the added effects (ER=0.0%, 95% CI: -3.8%, 4.0%) on the current day. The main effect peaked at lag0-2, and was higher for the two rural areas compared to the two cities, for respiratory compared to cardiovascular mortality, for those ≥75 years old and for females. The modifying effects of heat wave characteristics and community characteristics on mortality were not statistically significant.
  
  
  CONCLUSIONS
  This study suggests the effects of extreme heat were mainly driven by high temperature, which can be modified by some individual characteristics.
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Weilin
authors.initials: W
authors.lastname: Zeng
authors.affiliation: School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, China.
authors.forename: Xiangqian
authors.initials: X
authors.lastname: Lao
authors.affiliation: Center for Environment and Population Health, School of Environment, Griffith University, Australia.
authors.forename: Shannon
authors.initials: S
authors.lastname: Rutherford
authors.affiliation: Institute of Chronic Non-communicable Disease Control and Prevention, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institute of Chronic Non-communicable Disease Control and Prevention, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Xu
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Hualiang
authors.initials: H
authors.lastname: Lin
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Jianpeng
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China.
authors.forename: Mengjue
authors.initials: M
authors.lastname: Hu
authors.affiliation: Center for Environment and Population Health, School of Environment, Griffith University, Australia.
authors.forename: Cordia
authors.initials: C
authors.lastname: Chu
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China. Electronic address: mwj68@vip.tom.com.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Ma
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D002947:Cities / Q000453:epidemiology* / Q000706:statistics & numerical data; D055874:Extreme Heat; D005260:Female; D006801:Humans; D008297:Male; D009026:Mortality / Q000639:trends*; D017711:Nonlinear Dynamics
keywords: China; Climate change; Extreme temperature; Heat waves; Mortality