title: Short-term effects of the 2008 cold spell on mortality in three subtropical cities in Guangdong Province, China.
abstract: BACKGROUND
  Few studies have been conducted to investigate the impact of extreme cold events on mortality in subtropical regions.
  
  
  OBJECTIVE
  In the present study we aimed to investigate the effects of the 2008 cold spell on mortality and the possibility of mortality displacement in three subtropical cities in China.
  
  
  METHODS
  Daily mortality, air pollution, and weather data were collected from 2006 to 2009 in Guangzhou, Nanxiong (no air pollutants), and Taishan. We used a polynomial distributed lag model (DLM) to analyze the relationship between the 2008 cold spell and mortality. To observe the mortality displacement of the cold spell, we estimated the cumulative effects at lag0, lag0-6, lag0-13, lag0-20, and lag0-27 separately.
  
  
  RESULTS
  During the 2008 cold spell, the cumulative risk of nonaccidental mortality increased significantly in Guangzhou [relative risk (RR) = 1.60; 95% CI: 1.19, 2.14] and Taishan (RR = 1.60; 95% CI: 1.06, 2.40) when lagged up to 4 weeks after the cold spell ended. Estimated effects at lag0-27 were more pronounced for males than for females, for respiratory mortality than for cardiovascular mortality, and for the elderly (≥ 75 years of age) than for those 0-64 years of age. Most of the cumulative RRs increased with longer lag times in Guangzhou and Taishan. However, in Nanxiong, the trend with cumulative RRs was less consistent, and we observed no statistically significant associations at lag0-27.
  
  
  CONCLUSIONS
  We found associations between the 2008 cold spell and increased mortality in the three subtropical cities of China. The lag effect structure of the cold spell varied with location and the type of mortality, and evidence of short-term mortality displacement was inconsistent. These findings suggest that extreme cold is an important public health problem in subtropical regions.
authors.affiliation: Guangdong Provincial Institute of Public Health, Guangzhou, Guangdong, China.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Xie
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Yao
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Xu
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Xu
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Hualiang
authors.initials: H
authors.lastname: Lin
authors.forename: Xiangqian
authors.initials: X
authors.lastname: Lao
authors.forename: Shannon
authors.initials: S
authors.lastname: Rutherford
authors.forename: Cordia
authors.initials: C
authors.lastname: Chu
authors.forename: Cunrui
authors.initials: C
authors.lastname: Huang
authors.forename: Scott
authors.initials: S
authors.lastname: Baum
authors.forename: Wenjun
authors.initials: W
authors.lastname: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D002980:Climate; D003080:Cold Temperature; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009026:Mortality