Characterizing temperature and mortality in nine California counties
Characterizing temperature and mortality in nine California counties
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DOI：
10.1097/ede.0b013e31815c1da7
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发表时间：
2008-01-01
期刊：
影响因子：
5.4
通讯作者：
Ostro, Bart D.
中科院分区：
文献类型：
--
作者：
Basu, Rupa;Feng, Wen-Ying;Ostro, Bart D.
背景：气温升高与死亡率增加有关。然而，很少有流行病学研究将空气污染物视为潜在的混杂因素或影响调节因素。没有一个研究关注加利福尼亚州，那里气候普遍温和，污染水平往往较高，这是检验温度与空气污染的独立影响的理想环境。 方法：我们研究了 1999 年 5 月至 9 月至 2003 年 9 月加利福尼亚州 9 个县的平均日表观温度与非意外死亡率之间的关联。数据来自国家气候数据中心（温度和相对湿度）、加州卫生服务部（死亡率）和加州空气资源委员会（颗粒物、臭氧、一氧化碳和二氧化氮）。我们进行了时间分层病例交叉研究，以时间序列分析作为敏感性分析，使用两种方法对星期几进行调整，并对时间序列分析中的时间趋势进行调整。我们首先获得了特定县的估计值，然后使用荟萃分析方法将它们合并起来。结果：总共包括 248,019 例死亡。在所有 9 个县的病例交叉分析中，当日平均表观温度每升高 10 度（华氏度），死亡率就会增加 2.3%（95% 置信区间 = 1.0%-3.6%），时间序列分析得出的结果几乎相同。没有发现所检查的空气污染物是显着的混杂因素或影响调节剂。结论：即使没有极端的表观温度，我们也观察到加利福尼亚州温度与死亡率之间存在独立于空气污染的关联。
Background: Elevated temperature has been associated with increased mortality. Few epidemiologic studies, however, have considered air pollutants as potential confounders or effect modifiers. None has focused on California, where the climate is generally mild and pollution levels tend to be high-an ideal setting to examine the independent effect of temperature from air pollution.Methods: We examined the association between mean daily apparent temperature and nonaccidental mortality in 9 counties throughout California from May to September 1999-2003. Data were obtained from the National Climatic Data Center (temperature and relative humidity), the California Department of Health Services (mortality), and the California Air Resources Board (particulate matter, ozone, carbon monoxide, and nitrogen dioxide). We conducted a time-stratified case-crossover study, with a time-series analysis as a sensitivity analysis, adjusting for day of the week using both methods and adjusting for time trend in the time-series analysis. We first obtained county-specific estimates and then combined them using meta-analytic methods.Results: A total of 248,019 deaths were included. Each 10 degrees (Fahrenheit) increase in same-day mean apparent temperature corresponded to a 2.3% increase in mortality (95% confidence interval = 1.0%-3.6%) in the case-crossover analysis for all 9 counties combined, with nearly identical results produced from the time-series analysis. No air pollutant examined was found to be a significant confounder or effect modifier.Conclusions: Even without extremes in apparent temperature, we observed an association between temperature and mortality in California that was independent of air pollution.