title: Association of cold temperature and mortality and effect modification in the subtropical plateau monsoon climate of Yuxi, China.
abstract: Consistent evidence has shown excess mortality associated with cold temperature, but some important details of the cold-mortality association (e.g. slope and threshold) have not been adequately investigated and few studies focused on the cold effect in high-altitude areas of developing countries. We attempted to quantify the cold effect on mortality, identify the details, and evaluate effect modification in the distinct subtropical plateau monsoon climate of Yuxi, a high plateau region in southwest China.
  
  
  
  From daily mortality and meteorological data during 2009-2014, we used a quasi-Poisson model combined with a "natural cubic spline-natural cubic spline" distributed lag non-linear model to estimate the temperature-mortality relationship and then a simpler "hockey-stick" model to investigate the cold effect and details.
  
  
  
  Cold temperature was associated with increased mortality, and the relative risk of cold effect (1st relative to 10th temperature percentile) on non-accidental, cardiovascular, and respiratory mortality for lag 0-21 days was 1.40 (95% confidence interval: 1.19-1.66), 1.61 (1.28-2.02), and 1.13 (0.78-1.64), respectively. A 1°C decrease below a cold threshold of 9.1°C (8th percentile) for lags 0-21 was associated with a 7.35% (3.75-11.09%) increase in non-accidental mortality. The cold-mortality association was not significantly affected by cause-specific mortality, gender, age, marital status, ethnicity, occupation, or previous history of hypertension.
  
  
  
  There is an adverse impact of cold on mortality in Yuxi, China, and a temperature of 9.1°C is an important cut-off for cold-related mortality for residents.
authors.affiliation: Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong 515041, China; Yuxi Center for Disease Control and Prevention, Yuxi, Yunnan 653000, China.
authors.forename: Zan
authors.initials: Z
authors.lastname: Ding
authors.affiliation: Yuxi Center for Disease Control and Prevention, Yuxi, Yunnan 653000, China.
authors.forename: Liujiu
authors.initials: L
authors.lastname: Li
authors.affiliation: Yuxi Center for Disease Control and Prevention, Yuxi, Yunnan 653000, China.
authors.forename: Ruqin
authors.initials: R
authors.lastname: Wei
authors.affiliation: Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Wenya
authors.initials: W
authors.lastname: Dong
authors.affiliation: Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Pi
authors.initials: P
authors.lastname: Guo
authors.affiliation: Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong 515041, China.
authors.forename: Ju
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Preventive Medicine, Shantou University Medical College, Shantou, Guangdong 515041, China. Electronic address: qyzhang@stu.edu.cn.
authors.forename: Qingying
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000368:Aged; D002681:China / Q000453:epidemiology; D002980:Climate; D003080:Cold Temperature; D005260:Female; D006801:Humans; D008297:Male; D009026:Mortality
keywords: Cold temperature; Distributed lag non-linear model; Effect modification; Mortality