A Systematic Review and Meta-Analysis of the Association between Daily Mean Temperature and Mortality in China

摘要

Introduction: We summarized the evidence of the effects of exposure to hot and cold temperatures on mortality in China. We included studies published in Chinese and English. Materials and methods: We conducted a systematic search of peer-reviewed studies published up to the end of 2016 on daily mean temperature and mortality. Studies were drawn from four English databases-PubMed, MEDLINE, SciVerse Scopus, and Web of Science-as well as one Chinese database, China Knowledge Resource Integrated Database (www.cnki.net). The effect estimates of heat/cold were converted to relative risks (RR) associated with 1 degree increase/decrease beyond the heat/cold reference temperatures. For studies that provided lag-specific estimates, we used both the maximum and minimum of RR estimates. Summary effect estimates for all-cause and cause-specific mortalities, as well as RRs stratified by sex, age, and socio-economic status were calculated. We also investigated patterns of adaptation to hot and cold temperatures at different latitudes and at different reference temperatures. Results: We included a total of 34 articles in this systematic review and meta-analysis. For 1 degree temperature decrease/increase beyond reference points, the risk of non-accidental mortality increased by 3% (RR, 1.03; 95% CI [1.03-1.04]) for cold and 2% (RR, 1.02; 95% CI [1.02-1.03]) for heat, respectively. The risk of cause-specific (cardiovascular, respiratory, cerebrovascular) mortalities increased between 3% and 4% for cold and between 3% and 4% for heat. We identified variation in optimal temperature range related to latitude of the residential area, and differences in people's ability to adapt to heat versus cold. Conclusion: We found consistent evidence of the association between temperature and mortality, as well as evidence of patterns in human adaptation. We discussed implications of these findings for China and for future research activities.