Interdepartmental Centre of Bioclimatology, University of Florence, Piazzale delle Cascine 18, 50144 Firenze, Italy.
Stroke. 2011 Mar;42(3):593-600. doi: 10.1161/STROKEAHA.110.602037. Epub 2011 Jan 27.
Results on the effect of weather on stroke occurrences are still confusing and controversial. The aim of this study was to retrospectively investigate in Tuscany (central Italy) the weather-related stroke events through the use of an innovative source of weather data (Reanalysis) together with an original statistical approach to quantify the prompt/delayed health effects of both cold and heat exposures.
Daily stroke hospitalizations and meteorologic data from the Reanalysis 2 Achieve were obtained for the period 1997 to 2007. Generalized linear and additive models and an innovative modeling approach, the constrained segmented distributed lag model, were applied.
Both daily averages and day-to-day changes of air temperature and geopotential height (a measure that approximates the mean surface pressure) were selected as independent predictors of all stroke occurrences. In particular, a 5°C temperature decrease was associated with 16.5% increase of primary intracerebral hemorrhage of people ≥65 years of age. A general short-term cold effect on hospitalizations limited to 1 week after exposure was observed and, for the first time, a clear harvesting effect (deficit of hospitalization) for cold-related primary intracerebral hemorrhage was described. Day-to-day changes of meteorologic parameters disclosed characteristic U- and J-shaped relationships with stroke occurrences.
Thanks to the intrinsic characteristic of Reanalysis, these results might simply be implemented in an operative forecast system regarding weather-related stroke events with the aim to develop preventive health plans.
关于天气对中风发作影响的结果仍然令人困惑和有争议。本研究的目的是通过使用创新的天气数据源（再分析）以及量化冷暴露和热暴露即时和延迟健康影响的原始统计方法，回顾性地研究托斯卡纳（意大利中部）的与天气相关的中风事件。
获得了 1997 年至 2007 年期间的中风住院和再分析 2 号的气象数据。应用广义线性和加性模型以及一种创新的建模方法——受限制分段分布滞后模型。
空气温度和位势高度（一种近似平均地面压力的量度）的日平均值和日变化均被选为所有中风发作的独立预测因子。特别是，65 岁以上人群的温度下降 5°C，原发性脑出血的发生率增加 16.5%。观察到短期寒冷暴露后 1 周内住院人数的短期寒冷效应，并且首次描述了与寒冷相关的原发性脑出血的明显收割效应（住院人数不足）。气象参数的日变化与中风发作之间存在着典型的 U 形和 J 形关系。
由于再分析的内在特征，这些结果可以简单地应用于与天气相关的中风事件的操作性预测系统中，旨在制定预防保健计划。
