热浪对居民循环系统疾病死亡影响的病例交叉研究

Impact of heatwaves on daily death from cardiovascular diseases:a case-crossover study

目的探讨浙江省嘉兴市热浪对居民循环系统疾病日死亡人数的影响。方法本研究中热浪定义为日最高温度不低于35℃,且持续不少于3 d。采用时间分层的病例交叉设计方法,调整每日平均气温、降水量、平均风速、平均气压和空气污染指数建立条件Poisson回归模型,分析嘉兴市2008~2011年热浪与居民循环系统疾病死亡的关系,并分析滞后效应。结果 2008~2011年共出现6次热浪。滞后2 d时热浪对循环系统疾病死亡数影响的效应值最大,RR值为1.342(95%CI:1.081~1.667)。热浪对≥65岁老年人在滞后2 d时RR值最大,为1.296(95%CI:1.027~1.636),对女性在滞后2 d时RR值最大,为1.407(95%CI:1.021~1.937)。结论热浪会增加循环系统疾病死亡风险,且存在滞后效应;≥65岁老年人和女性为脆弱人群。

Objective To estimate the impact of heatwave on daily death from cardiovascular diseases（ CVD） in Jiaxing City,Zhejiang Province,China. Methods The definition of heatwave was a period at least 3 consecutive days with maximum temperature exceeding 35 ℃ in this study. Multivariate conditional Poisson regression models were applied to examine the heatwave-death association using the relative risk（ RR） while adjusting for meteorological and air pollution factors including daily average temperature,average rainfall,average wind speed,average pressure and air pollution index. The impacts were analyzed by using time-stratified case-crossover design based on relevant data from2008 to 2011 in Jiaxing City. The RR of different risk period was calculated to definite lag effects. Results Six heatwaves happened during the study period. The largest effect of the heatwave-CVD association was 1. 342（ 95% CI： 1.081-1. 667） at the 2 lag day. The risk of deaths from CVD among people ≥65 years old（ RR = 1. 296,95% CI： 1.027-1. 636） and female（ RR = 1. 407,95%CI： 1. 021-1. 937） increased at the 2 lag day. Conclusion Heatwave has impacts on the daily deaths caused by CVD and there are lagged effects. People at risk are female and people ≥65.