[A study on the identification of threshold for early warning on adverse weather events based on the association of apparent temperature and years of life lost].

Objective: To identify the threshold of a health warning system based on the association of apparent temperature and years of life lost (YLL). Methods: Daily mortality records and meteorological data were collected from 364 Chinese counties for 2006-2017. Distributed lag nonlinear model and multivariate Meta-analyses were applied to estimate the association between the apparent temperature and YLL rate. A regression tree model was employed to estimate the warning thresholds of the apparent temperature. Stratified analyses were further conducted by age and cause of death. Results: The daily YLL rate was 23.6/105. The mean daily apparent temperature was 15.7 ℃. U-shaped nonlinear associations were observed between apparent temperature and YLL rate. The actual temperature-caused YLL rate for the elderly was higher than the young population. The daily excess deaths rate increased with the higher effect levels. Conclusions: Regression tree model was employed to define the warning threshold for meteorological health risk. The present study provides theoretical support for the weather-related health warning system.目的： 基于体感温度-寿命损失年（YLL）暴露反应关系确定体感温度的健康风险预警阈值，为气象健康预警提供科学依据。 方法： 收集2006-2017年全国364个区（县）逐日死亡数据和气象数据。采用分布非线性滞后模型和多变量Meta分析方法分析体感温度与YLL率的暴露反应关系。基于该暴露反应关系，采用回归决策树模型确定体感温度的健康风险预警阈值。本研究按不同死因中不同年龄组进行分层分析。 结果： 研究期间总人群平均每日YLL率为23.6人年/10万，日均体感温度为15.7 ℃。不同人群体感温度与YLL率暴露反应关系均呈“U”形曲线，由体感温度导致老年人的YLL率远远高于年轻人。日均超额死亡数也随着风险等级的升高而上升。 结论： 基于体感温度与YLL率的暴露反应关系，利用回归决策树模型确定体感温度的健康风险预警阈值，经验证预警效果良好。本研究为建立气象健康风险预警系统提供参考。.