Jinjian Chen1, Jun Yang2, Maigeng Zhou3, Peng Yin3, Boguang Wang4, Jiangmei Liu3, Zhaoyue Chen5, Xiuping Song6, Chun-Quan Ou7, Qiyong Liu8. 1. State Key Laboratory of Organ Failure Research, Department of Biostatistics, School of Public Health, Southern Medical University, Guangzhou 510515, China; Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China. 2. Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China. Electronic address: yangjun_eci@jnu.edu.cn. 3. National Center for Chronic and Noncommunicable Disease Control and Prevention, Beijing 100050, China. 4. Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China. 5. State Key Laboratory of Organ Failure Research, Department of Biostatistics, School of Public Health, Southern Medical University, Guangzhou 510515, China. 6. State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China. 7. State Key Laboratory of Organ Failure Research, Department of Biostatistics, School of Public Health, Southern Medical University, Guangzhou 510515, China. Electronic address: ocq@smu.edu.cn. 8. State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China. Electronic address: liuqiyong@icdc.cn.
Abstract
BACKGROUND: In the context of global warming, most researches have been conducted on health influences of heat waves, with limited understanding of health impacts of cold spells, especially for developing countries. METHODS: We collected daily mortality and meteorological data for 31 capital cities across China during the maximum period of 2007-2013. A quasi-Poisson regression model combined with a distributed lag non-linear model was used to estimate the short-term effects of cold spells on mortality in cold seasons (November to March). 19 definitions of cold spell were clearly compared, including three definitions from the China Meteorological Administration (CMA) and 16 definitions by combining two temperature indicators (daily minimum and mean temperature), two temperature thresholds (3rd and 5th percentile) and four durations of at least 2-5 days. Then, a random effect meta-analysis was applied to pool the effect estimates at national level. Furthermore, a stratified analysis was constructed to identify the vulnerable subpopulations to cold spells. RESULTS: The definition, in which daily mean temperature falls below 5th percentile for at least two consecutive days, produced the optimum model fit performance. Generally, the mortality risk increased to the maximum after 3-6 days' exposure to cold spell and then leveled off in the next 3 weeks. The pooled relative risks (RR) of non-accidental mortality for cold spells were 1.03 (95% CI: 1.01-1.05), 1.27 (1.19-1.35) and 1.55 (1.40-1.70) at lag 0, lag 0-14 and lag 0-27 days, respectively. The greatest effect estimates of cold spells were found among total respiratory diseases and COPD, with RR of 1.88 (1.65-2.11) and 1.88 (1.58-2.19), respectively. The elderly, less-educated individuals and residents in southern China were more vulnerable to cold spells. CONCLUSION: There are remarkable mortality effects of cold spells, with effect estimates varying with the definition of cold spell and subpopulations. Using the official definition of cold spells may fail to capture the mortality risk associated with cold spells. These findings may facilitate the development of cold alert warning system and preventive actions to the vulnerable populations.
BACKGROUND: In the context of global warming, most researches have been conducted on health influences of heat waves, with limited understanding of health impacts of cold spells, especially for developing countries. METHODS: We collected daily mortality and meteorological data for 31 capital cities across China during the maximum period of 2007-2013. A quasi-Poisson regression model combined with a distributed lag non-linear model was used to estimate the short-term effects of cold spells on mortality in cold seasons (November to March). 19 definitions of cold spell were clearly compared, including three definitions from the China Meteorological Administration (CMA) and 16 definitions by combining two temperature indicators (daily minimum and mean temperature), two temperature thresholds (3rd and 5th percentile) and four durations of at least 2-5 days. Then, a random effect meta-analysis was applied to pool the effect estimates at national level. Furthermore, a stratified analysis was constructed to identify the vulnerable subpopulations to cold spells. RESULTS: The definition, in which daily mean temperature falls below 5th percentile for at least two consecutive days, produced the optimum model fit performance. Generally, the mortality risk increased to the maximum after 3-6 days' exposure to cold spell and then leveled off in the next 3 weeks. The pooled relative risks (RR) of non-accidental mortality for cold spells were 1.03 (95% CI: 1.01-1.05), 1.27 (1.19-1.35) and 1.55 (1.40-1.70) at lag 0, lag 0-14 and lag 0-27 days, respectively. The greatest effect estimates of cold spells were found among total respiratory diseases and COPD, with RR of 1.88 (1.65-2.11) and 1.88 (1.58-2.19), respectively. The elderly, less-educated individuals and residents in southern China were more vulnerable to cold spells. CONCLUSION: There are remarkable mortality effects of cold spells, with effect estimates varying with the definition of cold spell and subpopulations. Using the official definition of cold spells may fail to capture the mortality risk associated with cold spells. These findings may facilitate the development of cold alert warning system and preventive actions to the vulnerable populations.
Authors: Chengzhen Meng; Fang Ke; Yao Xiao; Suli Huang; Yanran Duan; Gang Liu; Shuyuan Yu; Yingbin Fu; Ji Peng; Jinquan Cheng; Ping Yin Journal: Front Public Health Date: 2022-01-24
Authors: Huan Li; Min Li; Shiyu Zhang; Zhengmin Min Qian; Zilong Zhang; Kai Zhang; Chongjian Wang; Lauren D Arnold; Stephen Edward McMillin; Shaowei Wu; Fei Tian; Hualiang Lin Journal: Sci Total Environ Date: 2022-01-04 Impact factor: 7.963