RESUMO
Objective@#To examine the impact of heat waves and cold spells on the incidence of hemorrhagic stroke, so as to provide insights into prevention of hemorrhagic stroke.@*Methods@#Data pertaining to the incidence of hemorrhagic stroke in Zibo City from 2015 to 2019 were collected from Shandong Provincial Management Information System for Chronic Diseases and Cause of Death Surveillance, and the meteorological data during the period from 2015 to 2019 were captured from National Meteorological Information Center of China. The air quality index (AQI) was collected from the National Daily Report of Urban Air Quality in China. Heat wave was defined as the highest daily temperature that was no less than the 90th percentile (P90), P92.5, P95 and P97.5 of the highest daily temperature in the warm season for at least 2, 3 or 4 days, and cold spell was defined as the lowest daily temperature that was no more than the P10, P7.5, P5 and P2.5 of the lowest daily temperature in the cold season for at least 2, 3 or 4 days. The effect of heat waves and cold spells on the incidence of hemorrhagic stroke was evaluated using a generalized additive model and described with relative risk (RR) and its 95%CI.@*Results@#A total of 8 844 case with first-onset hemorrhagic stroke were recorded in Zibo City from 2015 to 2019. The lowest daily temperature that was no more than P10, P7.5 or P5 of the lowest daily temperature in the cold season for at least two days, or that was no more than P10 or P7.5 of the lowest daily temperature for at least 3 days resulted a remarkably increased risk of hemorrhagic stroke (lowest RR=1.187, 95%CI: 1.031-1.366; highest RR=1.242, 95%CI: 1.042-1.480), and after adjusting the effect of daily mean temperature, the lowest daily temperature that was no more than P10 or P7.5 of the lowest daily temperature in the cold season for at least two days, or that was no more than P10 of the lowest daily temperature for at least 3 days resulted a remarkably increased risk of hemorrhagic stroke (lowest RR=1.236, 95%CI: 1.009-1.513; highest RR=1.274, 95%CI: 1.023-1.585). However, there was no significant association between heat waves and the risk of hemorrhagic stroke.@*Conclusion@#Cold spells may increase the risk of hemorrhagic stroke, while no significant association is examined between heat waves and the risk of hemorrhagic stroke.
RESUMO
Objective@#To estimate future excess mortality attributable to cold spells in Guangzhou, China.@*Methods@#We collected the mortality data and metrological data from 2009-2013 of Guangzhou to calculated the association between cold spell days and non-accidental mortality with GLM model. Then we projected future daily average temperatures (2020-2039 (2020s) , 2050-2069 (2050s) , 2080-2099 (2080s) ) with 5 GCMs models and 2 RCPs (RCP4.5 and RCP8.5) to identify cold spell days. The baseline period was the 1980s (1980-1999). Finally, calculated the yearly cold spells related excess death of 1980s, 2020s, 2050s, and 2080s with average daily death count of non-cold spell days, exposure-response relationship, and yearly number of cold spell days.@*Results@#The average of daily non-accidental mortality in Guangzhou from 2009 to 2013 was 96, and the average of daily average was 22.0 ℃. Cold spell days were associated with 3.3% (95%CI: 0.4%-6.2%) increase in non-accidental mortality. In 1980s, yearly cold spells related deaths were 34 (95%CI: 4-64). In 2020s, the number will increase by 0-10; in 2050s, the number will increase by 1-9; and in 2080s, will increase by 1-9 under the RCP4.5 scenario. In 2020s, the number will increase by 0-9; in 2050s, the number will increase by 1-6; and in 2080s, will increase by 0-11 under the RCP8.5 scenario.@*Conclusion@#The cold spells related non-accidental deaths in Guangzhou will increase in future under climate change.