[The definition of heat-wave based on mortality risk assessment in different regions of China].

Objective: To identify the definition of heat wave based on mortality risk assessment in different regions of China. Methods: Daily mortality (from China Information System for Disease Control and Prevention) and meteorological data (from National Meteorological Information Center in China) from 66 counties with a population of over 200 000 were collected from 2006-2011. With the consideration of climate type and administrative division, China was classified as seven regions. Firstly, distributed lag non-linear model (DLNM) was used to estimate community-specific effects of temperature on non-accidental mortality. Secondly, a multivariate meta-analysis was applied to pool the estimates of community-specific effects to explore the region-specific temperature threshold and the duration for definition of heat wave. Results: We defined regional heat wave of Northeast, North, Northwest, East, Central and Southwest China as being two or more consecutive days with daily mean temperature higher than or equal to the P(64), P(71), P(85), P(67), P(75) and P(77) of warm season (May to October) temperature, respectively, while the thresholds of temperature were 21.6, 23.7, 24.3, 25.7, 28.0 and 25.3 ℃. The heat wave in South China was defined as five or more consecutive days with daily mean temperature higher than or equal to the P(93) (30.4 ℃) of warm season (May to October) temperature. Conclusion: The region-specific definition of heat wave developed in our study may provide local government with the guidance of establishment and implementation of early heat-health response systems to address the negative health outcomes due to heat wave.目的： 通过分析中国不同地区极端高温与死亡的暴露-反应关系，构建不同区域的热浪定义。 方法： 收集2006—2011年中国人口超20万的66个疾病监测点气象（来源于中国气象数据网）和居民死亡数据（来源于中国疾病预防控制中心的中国疾病预防控制信息系统），结合气候类型、行政区域把中国分为7个区域。采用两阶段方法分析，第1阶段使用分布滞后非线性模型拟合每个监测点的温度-死亡关系，第2阶段采用多元Meta分析合并每个区域所有监测点的数据，获得区域性温度-死亡的关系，探索热浪的温度阈值和持续时间，建立每个区域基于死亡风险的热浪定义。 结果： 当日平均温度分别≥5—10月东北、华北、西北、华东、华中和西南日平均温度的P(64)、P(71)、P(85)、P(67)、P(75)、P(77)时，且该温度连续2 d及以上定义为热浪，对应的温度绝对阈值分别为21.6、23.7、24.3、25.7、28.0和25.3℃；华南地区热浪定义为日平均温度≥5—10月日平均温度的P(93)（30.4 ℃），持续5 d及以上的炎热天气。 结论： 根据死亡风险评估建立起具有区域性特征的热浪定义，不同区域的热浪预警温度不同。.