中国88个区/县大气臭氧对人群脑卒中死亡的急性效应研究

目的探究中国88个区/县大气臭氧（O₃）对人群脑卒中死亡的急性效应。方法利用分布在全国31个省级行政区的88个区/县2015－2018年每日脑卒中死亡、大气污染和气象的数据。 采用时间序列分析的方法，首先运用准泊松分布和广义相加模型相连接的方法，控制长期和季节变化趋势、气象因素和“星期几效应”的影响，定量分析各个区/县大气O₃对人群脑卒中死亡的影响，然后通过随机效应模型合并各区/县的效应值，获得88个区/县平均水平上O₃对人群脑卒中死亡的急性效应，并对O₃在不同区域、季节、性别和年龄的效应进行分层分析。结果在88个区/县平均水平上，大气O₃浓度（lag1）每升高10 μg/m3，人群脑卒中的死亡风险增加0.30%（95% CI:0.13%～0.47%）。 在区域平均水平上，华南地区的效应最强，为0.74%（95% CI:0.08%～1.40%）。 分层分析结果表明，O₃浓度对女性脑卒中死亡影响的效应值高于男性，分别为0.38%（95% CI:0.13%～0.63%）、0.23%（95% CI:0.002%～0.460%）；O₃和脑卒中死亡的关联强度在年长人群中更强；此外，暖季O₃的效应值略高于冷季，但经统计学检验，不同区域、季节、性别和年龄组间效应值的差异均无统计学意义。结论大气O₃浓度的升高增加了人群脑卒中死亡的风险，应加强开展O₃污染防治工作。

Acute effect of ozone on daily stroke mortality in 88 districts/counties of China

ObjectiveTo explore the acute effect of ozone on daily stroke mortality in 88 districts/counties of China.MethodsDaily stroke mortality and environment data from 2015 to 2018 in 88 districts/counties of China were collected to perform a time-series analysis. First, we linked Quasi-Poisson distribution with generalized additive model to evaluate the effect of ozone on daily stroke mortality in each districts/counties after adjusting the long-term and seasonal trend as well as meteorological factors and the effect of “days of week”. Then, we used random-effect models to pool districts/counties-specific estimates and obtain overall average summary estimates of acute effect of ozone on stroke mortality. We also conducted stratification analyses by regional, seasonal and demographic factors (sex and age).ResultsAt the overall average level, a 10 μg/m3 increase in ozone concentration (lag1) was associated with 0.30% of risk increase of daily mortality form stroke (95% CI : 0.13%-0.47%). At the area specific average level, the acute effect was strongest in the districts/counties in southern China, and the estimate was 0.74% (95% CI : 0.08%-1.40%). Sex specific analysis indicated that each 10 μg/m3 increase in ozone concentration was associated with an increase of 0.38% (95% CI: 0.13%-0.63%) and 0.23% (95% CI: 0.002%-0.460%) of daily stroke mortality in females and males, respectively. The association were stronger in warm season and in older people. However, there were no statistically significant differences in associations between ozone and daily stroke mortality according to region, season, sex and age.ConclusionThe increase in air ozone concentration can increase the risk of stroke mortality. It is necessary to strengthen the prevention and control of ozone pollution.