Mathes Robert W, Ito Kazuhiko, Lane Kathryn, Matte Thomas D
New York City Department of Health and Mental Hygiene, Queens, New York, United States of America.
PLoS One. 2017 Sep 6;12(9):e0184364. doi: 10.1371/journal.pone.0184364. eCollection 2017.
The impact of heat on mortality is well documented but deaths tend to occur after (or lag) extreme heat events, and mortality data is generally not available for timely surveillance during extreme heat events. Recently, systems for near-real time surveillance of heat illness have been reported but have not been validated as predictors of non-external cause of deaths associated with extreme heat events. We analyzed associations between daily weather conditions, emergency medical system (EMS) calls flagged as heat-related by EMS dispatchers, emergency department (ED) visits classified as heat-related based on chief complaint text, and excess non-external cause mortality in New York City. EMS and ED data were obtained from data reported daily to the city health department for syndromic surveillance. We fit generalized linear models to assess the relationships of daily counts of heat related EMS and ED visits to non-external cause deaths after adjustment for weather conditions during the months of May-September between 1999 and 2013. Controlling for temporal trends, a 7% (95% confidence interval (CI): 2-12) and 6% (95% CI: 3-10) increase in non-external cause mortality was associated with an increase from the 50th percentile to 99th percentile of same-day and one-day lagged heat-related EMS calls and ED visits, respectively. After controlling for both temporal trends and weather, we observed a 7% (95% CI: 3-12) increase in non-external cause mortality associated with one-day lagged heat-related EMS calls and a 5% mortality increase with one-day lagged ED visits (95% CI: 2-8). Heat-related illness can be tracked during extreme heat events using EMS and ED data which are indicators of heat associated excess non-external cause mortality during the warm weather season.
高温对死亡率的影响已有充分记录，但死亡往往发生在极端高温事件之后（或有滞后性），而且在极端高温事件期间，通常无法及时获取死亡率数据用于监测。最近，已有关于热相关疾病近实时监测系统的报道，但这些系统尚未被验证为与极端高温事件相关的非外部死因的预测指标。我们分析了纽约市每日天气状况、紧急医疗服务（EMS）调度员标记为与热相关的EMS呼叫、基于主诉文本分类为与热相关的急诊科（ED）就诊以及非外部原因超额死亡率之间的关联。EMS和ED数据来自每日上报给城市卫生部门用于症状监测的数据。我们拟合广义线性模型，以评估在1999年至2013年5月至9月期间，调整天气状况后，与热相关的EMS和ED就诊的每日计数与非外部原因死亡之间的关系。在控制时间趋势后，非外部原因死亡率分别在当日和滞后一天的与热相关的EMS呼叫和ED就诊从第50百分位数增加到第99百分位数时，出现了7%（95%置信区间（CI）：2 - 12）和6%（95% CI：3 - 10）的增长。在同时控制时间趋势和天气后，我们观察到与滞后一天的与热相关的EMS呼叫相关的非外部原因死亡率增加了7%（95% CI：3 - 12），与滞后一天的ED就诊相关的死亡率增加了5%（95% CI：2 - 8）。在极端高温事件期间，可以使用EMS和ED数据追踪与热相关的疾病，这些数据是温暖季节与热相关的非外部原因超额死亡率的指标。
