Quantitative lagged effects of extreme temperature on stroke deaths in a coastal city
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摘要: 当夏季和冬季出现极端气温时,脑卒中死亡有明显增加,但不同地区极端气温对脑卒中死亡的影响不同。以宁波为沿海城市的代表,采用2013—2019年宁波市脑卒中死亡病例和同期的气温数据,利用分布滞后非线性模型(DLNM),研究了极端气温对不同群组脑卒中死亡的滞后定量影响。结果表明:(1)极端高温对除低龄组外的其他人群脑卒中死亡效应趋势基本一致,即累积相对危险度(RR)及95%置信区间(95%CI)随时间延长增大,热累积促进效应随时间增强,对全部人群滞后3 d内的脑卒中死亡有促进效应。40℃滞后0—1 d、0—2 d和0—3 d累积相对危险度(95%CI)分别为1.29(1.17—1.43)、1.38(1.22—1.55)和1.41(1.25—1.60)。(2)极端低温对不同人群脑卒中死亡促进效应趋势不同,对于全部人群,当天没有明显的促进效应,滞后第3到4天开始有明显的促进效应,累积相对危险度(95%CI)随时间增大,低温累积促进效应随时间增强,滞后15 d后对脑卒中死亡无明显的促进效应。−4℃滞后0—5 d、0—10 d和0—15 d累积相对危险度(95%CI)分别为1.23(1.00—1.50)、1.61(1.22—2.12)和1.95(1.39—2.75)。(3)极端气温对高龄组(≥65岁)脑卒中死亡的促进风险更高,对低龄组没有明显的促进或抑制效应。极端高温对男性热累积促进效应更强,极端低温对女性累积促进效应更强。Abstract: When extreme temperature occurs in summer or winter, the number of stroke deaths increases significantly. Extreme temperature has different effects on stroke death in different regions. This study takes Ningbo as a representative coastal city and the data of stroke deaths and temperature in Ningbo from 2013 to 2019 are used. Using the distributed lag nonlinear model (DLNM), the quantitative lagged effects of extreme temperature on stroke death in different groups of people are studied. Results are as follows: (1) The effect of extreme high temperature is basically the same for all the groups except the young group. The cumulative relative risk (RR) and 95% confidence interval (95%CI) increases with time, indicating that the cumulative lagged effect of heat effect increases with time. It has a 3 d lagged effect on stroke death for all groups. The cumulative relative risk (95%CI) at 0—1 d, 0—2 d and 0—3 d lags at 40℃ are 1.29 (1.17—1.43), 1.38 (1.22—1.55) and 1.41 (1.25—1.60). (2) The effect of extreme low temperature has different trends in stroke death for different groups. For all the groups, there is no obvious lagged effect on the first day. There is an obvious lagged effect from the third to the fourth days. The cumulative relative risk and 95%CI increases with time, indicating that the cumulative lagged effect of cold effect increases with time. There is no significant lagged effect on stroke death after 15 days. The cumulative relative risk (95%CI) at 0—5 d, 0—10 d and 0—15 d lags at −4℃ are 1.23 (1.00—1.50), 1.61 (1.22—2.12) and 1.95 (1.39—2.75). (3) For different subgroups, extreme temperature poses higher risk on stroke death in the elder group (≥65 years old), and has no obvious effect in the younger group. Extreme high temperature leads to higher risk on stroke death for men than for women, while extreme low temperature poses higher risk on stroke death for women than for men.
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Key words:
- Extreme temperature /
- Stroke death /
- Distributed lag nonlinear model(DLNM) /
- Lag effect
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表 1 2013—2019年宁波市气象要素、空气污染要素和脑卒中病例统计
Table 1. Descriptive statistics of meteorological factors,air pollution factors and stroke cases in Ningbo from 2013 to 2019
指标 平均值±标准差 最小值 25%分位数 中位数 75%分位数 最大值 极端高温(℃) 22.42±8.96 −2.50 15.05 23.30 29.40 42.10 极端低温(℃) 14.67±23.33 −6.70 7.30 15.30 22.10 29.40 相对湿度(%) 75.45±12.16 28.00 68.00 76.00 85.00 100.00 PM2.5(μg/m3) 48.78±34.06 0.00 27.00 41.00 60.00 458.00 日死亡人数(人) 18.13±5.78 3.00 14.00 17.00 22.00 42.00 日低龄组死亡人数(人) 1.52±1.26 0.00 1.00 1.00 2.00 8.00 日高龄组死亡人数(人) 16.61±5.53 3.00 13.00 16.00 20.00 39.00 日男性死亡人数(人) 9.48±3.43 1.00 7.00 9.00 12.00 27.00 日女性死亡人数(人) 8.65±3.43 0.00 6.00 8.00 11.00 25.00 表 2 35—40℃不同群组在有效滞后天数内对脑卒中死亡的累积相对危险度及95%置信区间
Table 2. Cumulative relative risk and 95%CI of stroke death for different groups at 35—40℃ within effective lag days
温度 群组 累积滞后天数 0 0—1 d 0—2 d 0—3 d 35℃ 全部人群 1.09(1.06—1.12) 1.15(1.10—1.21) 1.19(1.13—1.26) 1.21(1.14—1.28) ≥65岁 1.09(1.06—1.12) 1.15(1.10—1.20) 1.19(1.12—1.26) 1.20(1.13—1.28) <65岁 1.01(0.84—1.20)* 1.01(0.75—1.34)* 1.00(0.71—1.41)* 0.99(0.69—1.43)* 男 1.12(1.07—1.17) 1.21(1.12—1.30) 1.26(1.15—1.37) 1.27(1.15—1.40)* 女 1.05(1.02—1.09) 1.09(1.03—1.16) 1.12(1.04—1.20) 1.13(1.05—1.22)* 36℃ 全部人群 1.10(1.06—1.14) 1.18(1.11—1.24) 1.22(1.15—1.31) 1.24(1.16—1.34) ≥65岁 1.10(1.06—1.14) 1.18(1.11—1.24) 1.23(1.15—1.31) 1.24(1.16—1.34) <65岁 1.01(0.86—1.18)* 1.01(0.78—1.30)* 1.00(0.74—1.36)* 0.99(0.72—1.37)* 男 1.14(1.08—1.19) 1.24(1.15—1.34) 1.30(1.18—1.43) 1.32(1.19—1.46)* 女 1.06(1.02—1.11) 1.11(1.03—1.19) 1.14(1.05—1.24) 1.16(1.06—1.27)* 37℃ 全部人群 1.11(1.07—1.16) 1.20(1.13—1.28) 1.26(1.17—1.36) 1.28(1.19—1.41) ≥65岁 1.12(1.07—1.16) 1.21(1.13—1.29) 1.26(1.17—1.37) 1.28(1.18—1.40) <65岁 1.01(0.88—1.15)* 1.01(0.81—1.25)* 1.00(0.77—1.30)* 1.00(0.76—1.31)* 男 1.16(1.09—1.22) 1.28(1.17—1.40) 1.35(1.21—1.50) 1.37(1.22—1.54)* 女 1.07(1.02—1.13) 1.13(1.03—1.23) 1.16(1.05—1.29) 1.18(1.06—1.32)* 38℃ 全部人群 1.13(1.08—1.18) 1.23(1.14—1.33) 1.30(1.18—1.42) 1.32(1.20—1.46) ≥65岁 1.13(1.08—1.19) 1.24(1.14—1.34) 1.30(1.19—1.43) 1.33(1.21—1.47) <65岁 1.00(0.90—1.12)* 1.01(0.84—1.20)* 1.00(0.81—1.24)* 1.00(0.80—1.25)* 男 1.18(1.10—1.25) 1.31(1.19—1.46) 1.40(1.24—1.58) 1.43(1.25—1.63)* 女 1.08(1.01—1.15) 1.15(1.03—1.27) 1.19(1.05—1.34) 1.21(1.06—1.38)* 39℃ 全部人群 1.14(1.09—1.21) 1.26(1.16—1.37) 1.33(1.20—1.48) 1.37(1.22—1.53) ≥65岁 1.15(1.09—1.22) 1.27(1.16—1.39) 1.35(1.21—1.50) 1.38(1.23—1.55)* <65岁 1.00(0.92—1.09)* 1.00(0.88—1.15)* 1.00(0.85—1.18)* 1.00(0.84—1.18)* 男 1.20(1.11—1.29) 1.35(1.21—1.52) 1.45(1.26—1.67) 1.49(1.28—1.73)* 女 1.09(1.01—1.18) 1.16(1.03—1.31) 1.21(1.05—1.40) 1.24(1.06—1.44)* 40℃ 全部人群 1.16(1.09—1.24) 1.29(1.17—1.43) 1.38(1.22—1.55) 1.41(1.25—1.60) ≥65岁 1.17(1.10—1.25) 1.30(1.18—1.45) 1.39(1.23—1.59) 1.43(1.25—1.64)* <65岁 1.00(0.95—1.06)* 1.00(0.92—1.10)* 1.00(0.90—1.12)* 1.00(0.89—1.12)* 男 1.22(1.12—1.20) 1.40(1.22—1.59) 1.51(1.29—1.77) 1.55(1.31—1.84)* 女 1.10(1.01—1.20) 1.18(1.03—1.36) 1.24(1.05—1.46) 1.27(1.06—1.51)* 注:*表示不具有统计学意义。 表 3 −4—0℃不同群组在有效滞后天数内对脑卒中死亡的累积相对危险度及95%置信区间
Table 3. Cumulative relative risk values and 95%CI of stroke death for different groups at −4—0℃ within effective lag days
温度 群组 累积滞后天数 0 0—5 d 0—10 d 0—15 d 0℃ 全部人群 0.99(0.94—1.04)* 1.10(0.91—1.33) 1.44(1.12—1.85) 1.74(1.28—2.37)* ≥65岁 0.99(0.94—1.04)* 1.08(0.89—1.32) 1.42(1.10—1.85) 1.74(1.26—2.40) <65岁 1.03(0.98—1.07)* 1.11(0.91—1.34)* 1.13(0.86—1.47)* 1.14(0.81—1.61)* 男 1.07(1.02—1.11) 1.36(1.14—1.62) 1.54(1.21—1.97)* 1.61(1.18—2.20)* 女 0.97(0.91—1.04)* 1.05(0.81—1.36) 1.42(1.01—2.01) 1.74(1.14—2.66) −1℃ 全部人群 1.00(0.95—1.05)* 1.13(0.94—1.37) 1.48(1.15—1.91) 1.79(1.29—2.49) ≥65岁 0.99(0.94—1.04)* 1.11(0.91—1.36) 1.46(1.12—1.91) 1.79(1.29—2.49)* <65岁 1.03(0.97—1.09)* 1.12(0.89—1.42)* 1.15(0.84—1.58)* 1.17(0.78—1.76)* 男 1.07(1.03—1.12) 1.40(1.16—1.68) 1.59(1.24—2.04)* 1.66(1.20—2.29)* 女 0.98(0.92—1.05)* 1.07(0.82—1.39) 1.46(1.03—2.07) 1.78(1.15—2.75)* −2℃ 全部人群 1.00(0.96—1.05)* 1.16(0.96—1.41) 1.52(1.17—1.97) 1.84(1.33—2.54) ≥65岁 1.00(0.95—1.05)* 1.14(0.93—1.40) 1.50(1.15—1.97) 1.84(1.31—2.58) <65岁 1.03(0.97—1.10)* 1.14(0.87—1.50)* 1.18(0.81—1.71)* 1.20(0.75—1.93)* 男 1.08(1.03—1.13) 1.44(1.19—1.74) 1.64(1.26—2.13)* 1.71(1.23—2.39)* 女 0.98(0.92—1.05)* 1.09(0.83—1.42) 1.49(1.04—2.13) 1.82(1.17—2.85)* −3℃ 全部人群 1.01(0.96—1.06)* 1.19(0.98—1.46) 1.56(1.20—2.04) 1.90(1.36—2.64) ≥65岁 1.01(0.96—1.06)* 1.17(0.95—1.44) 1.55(1.17—2.04) 1.89(1.34—2.68) <65岁 1.04(0.96—1.12)* 1.16(0.85—1.60)* 1.20(0.75—2.02)* 1.23(0.71—2.14)* 男 1.09(1.04—1.15) 1.48(1.22—1.81) 1.75(1.31—2.32)* 1.77(1.25—2.51)* 女 0.99(0.92—1.06)* 1.11(0.85—1.46) 1.52(1.06—2.20) 1.87(1.19—2.96)* −4℃ 全部人群 1.02(0.97—1.07)* 1.23(1.00—1.50) 1.61(1.22—2.12) 1.95(1.39—2.75) ≥65岁 1.01(0.96—1.07)* 1.21(0.98—1.49) 1.59(1.19—2.11) 1.95(1.36—2.79) <65岁 1.04(0.95—1.14)* 1.18(0.82—1.70)* 1.23(0.75—2.02)* 1.27(0.68—2.37)* 男 1.10(1.04—1.16) 1.53(1.24—1.89) 1.75(1.31—2.32)* 1.83(1.27—2.63)* 女 0.99(0.93—1.06)* 1.14(0.86—1.51) 1.56(1.07—2.28) 1.92(1.20—3.08)* 注:*表示不具有统计学意义。 -
[1] 陈丽菁,方红,田秀红等. 2015. 2005—2014年上海市闵行区脑卒中死亡流行病学特征及时间趋势分析. 健康教育与健康促进,10(6):444-447Chen L J,Fang H,Tian X H,et al. 2015. Epidemiological characteristics and temporal trends of stroke mortality in Minhang district of Shanghai,2005-2014. Health Educ Health Promot,10(6):444-447 (in Chinese) [2] 陈亦晨,孙良红,李小攀等. 2019. 2002—2017年上海市浦东新区居民脑卒中死亡特征及减寿率分析. 中国全科医学,22(8):966-972Chen Y C,Sun L H,Li X P,et al. 2019. Mortality and years of life lost due to stroke among residents in Pudong new area of Shanghai between 2002 and 2017. Chinese Gen Pract,22(8):966-972 (in Chinese) [3] 陈亦晨,陈华,曲晓滨等. 2022. 日均气温对浦东新区居民脑卒中死亡影响的时间序列研究. 中国全科医学,25(15):1838-1844Chen Y C,Chen H,Qu X B,et al. 2022. Impact of average daily temperature on stroke mortality in Pudong New Area:A time-series analysis. Chinese Gen Pract,25(15):1838-1844 (in Chinese) [4] 陈月珍,林艺兰. 2016. 厦门市居民脑卒中死亡的流行病学研究. 疾病监测与控制,10(7):519-520Chen Y Z,Lin Y L. 2016. Epidemiologic study on mortality due to stroke in residents in Xiamen. J Dis Monitor Control,10(7):519-520 (in Chinese) [5] 何晓定,周迎春. 2020. 气象因素对上海市长宁区脑卒中死亡的影响. 实用预防医学,27(3):274-277He X D,Zhou Y C. 2020. Impact of meteorological factors on stroke death in Changning district,Shanghai. Pract Prev Med,27(3):274-277 (in Chinese) [6] 李娟,黄东辉,王冲等. 2017. 2013年辽宁省彰武和凤城地区脑卒中死亡特点分析. 中国慢性病预防与控制,25(2):147-151Li J,Huang D H,Wang C,et al. 2017. Analysis of death characteristics of stroke in Zhangwu and Fengcheng areas of Liaoning province from 2017 to 2013. Chinese J Chron Dis,25(2):147-151 (in Chinese) [7] 李诺,杨静,冯学泉等. 2017. 中国脑卒中死亡风险30年研究概述. 中华行为医学与脑科学杂志,26(8):765-768 doi: 10.3760/cma.j.issn.1674-6554.2017.08.020Li N,Yang J,Feng X Q,et al. 2017. A summary of 30 years' research on risk factors of stroke mortality in China. Chinese J Behav Med Brain Sci,26(8):765-768 (in Chinese) doi: 10.3760/cma.j.issn.1674-6554.2017.08.020 [8] 王陇德. 2015. 中国脑卒中防治报告—2015. 北京:中国协和医科大学出版社,5-6,68-69Wang L D. 2015. Report on the Chinese Stroke Prevention. Beijing:Peking Union Medical College Press,5-6,68-69 (in Chinese) [9] 王通,王丽楠,彭艳英等. 2019. 2016—2018年上海某远郊社区脑卒中高危人群筛查结果分析. 上海医药,40(22):52-55Wang T,Wang L N,Peng Y Y,et al. 2019. Analysis of screening results of stroke risk population in a remote suburban community of Shanghai from 2016 to 2018. Shanghai Med Pharm J,40(22):52-55 (in Chinese) [10] 王拥军,李子孝,谷鸿秋等. 2020. 中国卒中报告2019(中文版)(1). 中国卒中杂志,15(10):1037-1043 doi: 10.3969/j.issn.1673-5765.2020.10.001Wang Y J,Li Z X,Gu H Q,et al. 2020. China stroke statistics 2019(1). Chinese J Stroke,15(10):1037-1043 (in Chinese) doi: 10.3969/j.issn.1673-5765.2020.10.001 [11] 吴凯,张云权,邓芷晴等. 2016. 武汉江岸区2003—2014年脑卒中死亡分析. 浙江预防医学,28(2):168-170Wu K,Zhang Y Q,Deng Z Q,et al. 2016. Analysis of stroke deaths in Wuhan Jiang'an district from 2003 to 2014. Zhejiang Prev Med,28(2):168-170 (in Chinese) [12] 徐颖,陈远银,于绍轶等. 2017. 2012—2015年烟台市脑卒中流行病学特征分析. 现代预防医学,44(2):200-204Xu Y,Chen Y Y,Yu S Y,et al. 2017. Analysis of the epidemiological characteristics of stroke in Yantai city between 2012 and 2015. Mod Prev Med,44(2):200-204 (in Chinese) [13] 徐哲永,马浩,高大伟等. 2021. 1973—2019年浙江省极端最高气温时空演变特征研究. 科技通报,37(7):13-21Xu Z Y,Ma H,Gao D W,et al. 2021. Spatiotemporal evolution analysis on extreme daily maximum temperature over Zhejiang province during 1973-2019. Bull Sci Technol,37(7):13-21 (in Chinese) [14] 宇传华,罗丽莎,李梅等. 2016. 从全球视角看中国脑卒中疾病负担的严峻性. 公共卫生与预防医学,27(1):1-5Yu C H,Luo L S,Li M,et al. 2016. From the global views to understand the seriousness of the burden of stroke in China. J Public Health Prev Med,27(1):1-5 (in Chinese) [15] Anderson B G,Bell M L. 2009. Weather-related mortality:How heat,cold,and heat waves affect mortality in the United States. Epidemiology,20(2):205-213 doi: 10.1097/EDE.0b013e318190ee08 [16] Bai L,Ding G Q,Gu S H,et al. 2014. The effects of summer temperature and heat waves on heat-related illness in a coastal city of China,2011-2013. Environ Res,132:212-219 doi: 10.1016/j.envres.2014.04.002 [17] Basu R. 2009. High ambient temperature and mortality:A review of epidemiologic studies from 2001 to 2008. Environ Health,8:40 doi: 10.1186/1476-069X-8-40 [18] Bhaskaran K,Hajat S,Haines A,et al. 2009. Effects of ambient temperature on the incidence of myocardial infarction. Heart,95(21):1760-1769 doi: 10.1136/hrt.2009.175000 [19] Breitner S,Wolf K,Peters A,et al. 2014. Short-term effects of air temperature on cause-specific cardiovascular mortality in Bavaria,Germany. Heart,100(16):1272-1280 doi: 10.1136/heartjnl-2014-305578 [20] Chen R,Wang C,Meng X,et al. 2013. Both low and high temperature may increase the risk of stroke mortality. Neurology,81(12):1064-1070 doi: 10.1212/WNL.0b013e3182a4a43c [21] Chen R J,Yin P,Wang L J,et al. 2018. Association between ambient temperature and mortality risk and burden:Time series study in 272 main Chinese cities. BMJ,363:k4306 [22] Dilaveris P,Synetos A,Giannopoulos G,et al. 2006. Climate impacts on myocardial infarction deaths in the Athens Territory:The CLIMATE study. Heart,92(12):1747-1751 doi: 10.1136/hrt.2006.091884 [23] Gasparrini A,Armstrong B,Kenward M G. 2010. Distributed lag non-linear models. Stat Med,29(21):2224-2234 doi: 10.1002/sim.3940 [24] Gasparrini A,Armstrong B. 2011. The impact of heat waves on mortality. Epidemiology,22(1):68-73 doi: 10.1097/EDE.0b013e3181fdcd99 [25] Gasparrini A,Guo Y M,Hashizume M,et al. 2015. Mortality risk attributable to high and low ambient temperature:A multicountry observational study. Lancet,386(9991):369-375 doi: 10.1016/S0140-6736(14)62114-0 [26] Guo Y M,Barnett A G,Yu W W,et al. 2011. A large change in temperature between neighbouring days increases the risk of mortality. PLoS One,6(2):e16511 doi: 10.1371/journal.pone.0016511 [27] Guo Y M,Jiang F,Peng L,et al. 2012a. The association between cold spells and pediatric outpatient visits for asthma in Shanghai,China. PLoS One,7(7):e42232 doi: 10.1371/journal.pone.0042232 [28] Guo Y M,Punnasiri K,Tong S L. 2012b. Effects of temperature on mortality in Chiang Mai city,Thailand:A time series study. Environ Health,11(1):36 doi: 10.1186/1476-069X-11-36 [29] Guo Y M,Li S S,Zhang Y S,et al. 2013. Extremely cold and hot temperatures increase the risk of ischaemic heart disease mortality:Epidemiological evidence from China. Heart,2013,99(3):195-203 [30] Hajat S,Armstrong B G,Gouveia N,et al. 2005. Mortality displacement of heat-related deaths:A comparison of Delhi,São Paulo,and London. Epidemiology,16(5):613-620 doi: 10.1097/01.ede.0000164559.41092.2a [31] Huang Z J,Lin H L,Liu Y N,et al. 2015. Individual-level and community-level effect modifiers of the temperature-mortality relationship in 66 Chinese communities. BMJ Open,5(9):e009172 doi: 10.1136/bmjopen-2015-009172 [32] IPCC. 2021. Summary for policymakers∥IPCC. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press [33] Lavados P M,Olavarría V V,Hoffmeister L. 2018. Ambient temperature and stroke risk. Stroke,49(1):255-261 doi: 10.1161/STROKEAHA.117.017838 [34] Lawlor D A,Smith G D,Mitchell R,et al. 2004. Temperature at birth,coronary heart disease,and insulin resistance:Cross sectional analyses of the British women's heart and health study. Heart,90(4):381-388 doi: 10.1136/hrt.2002.009548 [35] Lowe D,Ebi K L,Forsberg B. 2011. Heatwave early warning systems and adaptation advice to reduce human health consequences of heatwaves. Int J Environ Res Public Health,8(12):4623-4648 doi: 10.3390/ijerph8124623 [36] McMichael A J,Wilkinson P,Kovats R S,et al. 2008. International study of temperature,heat and urban mortality:The 'ISOTHURM' project. Int J Epidemiol,37(5):1121-1131 doi: 10.1093/ije/dyn086 [37] Revich B,Shaposhnikov D. 2008. Temperature-induced excess mortality in Moscow,Russia. Int J Biometeorol,52(5):367-374 doi: 10.1007/s00484-007-0131-6 [38] Roger V L,Go A S,Lloyd-Jones D M,et al. 2012. Executive summary:Heart disease and stroke statistics–2012 update:A report from the American Heart Association:American heart association statistics committee and stroke statistics subcommittee. Circulation,125(1):188-197 doi: 10.1161/CIR.0b013e3182456d46 [39] Sun Z Q,Zheng L Q,Detrano R,et al. 2013. An epidemiological survey of stroke among rural Chinese adults results from the Liaoning province. Int J Stroke,8(8):701-706 doi: 10.1111/j.1747-4949.2012.00897.x [40] Vardoulakis S,Dear K,Hajat S,et al. 2014. Comparative assessment of the effects of climate change on heat- and cold- related mortality in the United Kingdom and Australia. Environ Health Perspect,122(12):1285-1292 doi: 10.1289/ehp.1307524 [41] Wang Z K,Hu S B,Sang S P,et al. 2017. Age-period-cohort analysis of stroke mortality in China:Data from the global burden of disease study 2013. Stroke,48(2):271-275 doi: 10.1161/STROKEAHA.116.015031 [42] Yang J,Yin P,Zhou M G,et al. 2016. The burden of stroke mortality attributable to cold and hot ambient temperatures:Epidemiological evidence from China. Environ Int,92-93:232-238 doi: 10.1016/j.envint.2016.04.001 [43] Zhang Y S,Li S S,Pan X C,et al. 2014. The effects of ambient temperature on cerebrovascular mortality:An epidemiologic study in four climatic zones in China. Environ Health,13(1):24 doi: 10.1186/1476-069X-13-24 [44] Zhou L,Chen K,Chen X D,et al. 2017. Heat and mortality for ischemic and hemorrhagic stroke in 12 cities of Jiangsu province,China. Sci Total Environ,601-602:271-277 doi: 10.1016/j.scitotenv.2017.05.169 -