title: The short-term effect of heat waves on mortality and its modifiers in China: an analysis from 66 communities.
abstract: BACKGROUND
  Many studies have reported increased mortality risk associated with heat waves. However, few have assessed the health impacts at a nation scale in a developing country. This study examines the mortality effects of heat waves in China and explores whether the effects are modified by individual-level and community-level characteristics.
  
  
  METHODS
  Daily mortality and meteorological variables from 66 Chinese communities were collected for the period 2006-2011. Heat waves were defined as ≥2 consecutive days with mean temperature ≥95th percentile of the year-round community-specific distribution. The community-specific mortality effects of heat waves were first estimated using a Distributed Lag Non-linear Model (DLNM), adjusting for potential confounders. To investigate effect modification by individual characteristics (age, gender, cause of death, education level or place of death), separate DLNM models were further fitted. Potential effect modification by community characteristics was examined using a meta-regression analysis.
  
  
  RESULTS
  A total of 5.0% (95% confidence intervals (CI): 2.9%-7.2%) excess deaths were associated with heat waves in 66 Chinese communities, with the highest excess deaths in north China (6.0%, 95% CI: 1%-11.3%), followed by east China (5.2%, 95% CI: 0.4%-10.2%) and south China (4.5%, 95% CI: 1.4%-7.6%). Our results indicate that individual characteristics significantly modified heat waves effects in China, with greater effects on cardiovascular mortality, cerebrovascular mortality, respiratory mortality, the elderly, females, the population dying outside of a hospital and those with a higher education attainment. Heat wave mortality effects were also more pronounced for those living in urban cities or densely populated communities.
  
  
  CONCLUSIONS
  Heat waves significantly increased mortality risk in China with apparent spatial heterogeneity, which was modified by some individual-level and community-level factors. Our findings suggest adaptation plans that target vulnerable populations in susceptible communities during heat wave events should be developed to reduce health risks.
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China; Center for Environment and Population Health, Griffith University, Brisbane 4111, Australia.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Ma
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China.
authors.forename: Weilin
authors.initials: W
authors.lastname: Zeng
authors.affiliation: The National Center for Chronic and Noncommunicable Disease Control and Prevention, Beijing 100050, China.
authors.forename: Maigeng
authors.initials: M
authors.lastname: Zhou
authors.affiliation: The National Center for Chronic and Noncommunicable Disease Control and Prevention, Beijing 100050, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.affiliation: Center for Environment and Population Health, Griffith University, Brisbane 4111, Australia.
authors.forename: Shannon
authors.initials: S
authors.lastname: Rutherford
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, 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 511430, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China.
authors.forename: Jianpeng
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Yewu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Chinese Center for Disease Control and Prevention, Beijing 102206, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Gu
authors.affiliation: Center for Environment and Population Health, Griffith University, Brisbane 4111, Australia.
authors.forename: Cordia
authors.initials: C
authors.lastname: Chu
mesh_terms: D000368:Aged; D002681:China / Q000453:epidemiology; D002947:Cities / Q000706:statistics & numerical data*; D055874:Extreme Heat; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D011156:Population Density; D012044:Regression Analysis
keywords: China; Climate change; Extreme temperature; Heat waves; Mortality