[Impact of daily mean temperature, cold spells, and heat waves on stroke mortality a multivariable Meta-analysis from 12 counties of Hubei province, China].

Objective: To assess the acute effects of daily mean temperature, cold spells, and heat waves on stroke mortality in 12 counties across Hubei province, China. Methods: Data related to daily mortality from stroke and meteorology in 12 counties across Hubei province during 2009-2012, were gathered. Distributed lag nonlinear model (DLNM) was first used, to estimate the county-specific associations between daily mean temperature, cold spells, heat waves and stroke mortality. Multivariate Meta-analysis was then applied to pool the community-specific relationships between temperature and stroke mortality (exposure-response relationship) as well as both cold- and- heat-associated risks on mortality at different lag days (lag-response relationship). Results: During 2009-2012, a total population of 6.7 million was included in this study with 42 739 persons died of stroke. An average of 2.7 (from 0.5 to 6.0) stroke deaths occurred daily in each county, with annual average mean temperature as 16.6 ℃ (from 14.7 ℃ to 17.4 ℃) during the study period. An inverse J-shaped association between temperature and stroke mortality was observed at the provincial level. Pooled mortality effect of cold spells showed a 2-3-day delay and lasted about 10 days, while effect of heat waves appeared acute but attenuated within a few days. The mortality risks on cold-spell days ranged from 0.968 to 1.523 in 12 counties at lag 3-14, with pooled effect as 1.180 (95%CI:1.043-1.336). The pooled mortality risk (ranged from 0.675 to 2.066) on heat-wave days at lag 0-2 was 1.114 (95%CI: 1.012-1.227). Conclusions: An inverse J-shaped association between temperature and stroke mortality was observed in Hubei province, China. Both cold spells and heat waves were associated with increased stroke mortality, while different lag patterns were observed in the mortality effects of heat waves and cold spells.目的： 分析平均气温、寒潮和热浪对湖北省12个区（县）居民脑卒中死亡的影响。 方法： 收集湖北省12个区（县）2009年1月1日至2012年12月31日脑卒中死亡监测资料和同期气象数据，应用分布滞后非线性模型（DLNM）评估各区（县）日均温度、寒潮和热浪与脑卒中死亡之间的关系，利用多元Meta分析合并12个区（县）的温度-脑卒中死亡的暴露-反应关系及寒潮和热浪对脑卒中死亡影响的滞后反应关系。 结果： 2009－2012年共观察670.2万人，纳入的脑卒中死亡人数为42 739例，各区（县）脑卒中日均死亡2.7（0.5~6.0）例，年均气温为16.6（14.7~17.4）℃。DLNM分析显示，日均气温与脑卒中死亡间呈反"J"形关系。寒潮对脑卒中死亡的影响存在2~3 d滞后，持续近10 d；热浪的效应则发生急促，持续时间较短。12个区（县）寒潮日滞后3~14 d，脑卒中累积死亡风险为0.968~1.523，合并风险RR=1.180（95%CI：1.043~1.336）；热浪日滞后0~2 d，脑卒中累积死亡风险为0.675~2.066，合并风险RR=1.114（95% CI：1.012~1.227）。 结论： 日均气温与湖北省居民脑卒中死亡呈反"J"形关系，寒潮和热浪均明显增加脑卒中死亡风险，但其死亡效应的滞后模式存在一定差异。.