Department of Neurology, West China Hospital of Sichuan University, No. 37 Wainan Guoxue Xiang, Chengdu, 610041, China.
Department of Neurology, Affiliated Hospital of Zunyi Medical College, Zunyi, China.
Environ Geochem Health. 2019 Oct;41(5):2113-2130. doi: 10.1007/s10653-019-00265-y. Epub 2019 Mar 8.
Stroke was demonstrated to correlate with seasonal variation. However, the relevant studies were incongruous. To better understand the rules of seasonal impact on ischemic stroke (IS) patients, we performed this meta-analysis. We systematically searched relevant observational studies in Pubmed, Web of science and Embase from January 1, 1980, to November 1, 2017, in English. Patients included in this study were adults who suffered from IS. Stata version 12.0 software was used to pool useful data and calculate incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). We also performed heterogeneity and sensitivity analyses and evaluated publication bias. Thirty-three observational studies involving 234,196 participants were incorporated into the meta-analysis. Summer and December were regarded as reference, respectively. The IRRs were calculated showing: IRR 1.05 (95% CI 1.04-1.07), IRR 1.03 (95% CI 1.02-1.04), IRR 1.02 (95% CI 1.01-1.03). No obvious difference existed among 12 months. Stratified analyses on Köppen classification were also conducted. Between-study heterogeneity was discovered; however, predefined stratified analyses and meta-regression could not reduce this heterogeneity. Our meta-analysis has revealed very little seasonal variation in the overall study. Both cold and hot months may be high risky for IS after stratified by Köppen Climate Classification. Thus, a rationale to environmental setting of risky patient management could be provided. More studies with specific assessments are warranted for further comprehensive investigation.
卒中与季节性变化相关。然而，相关研究结果并不一致。为了更好地了解季节变化对缺血性卒中（IS）患者的影响规律，我们进行了这项荟萃分析。我们系统地检索了 1980 年 1 月 1 日至 2017 年 11 月 1 日发表在 Pubmed、Web of science 和 Embase 上的相关观察性研究，纳入的患者为成人 IS 患者。使用 Stata 版本 12.0 软件汇总有用数据，并计算发病率比值（IRR）及其 95%置信区间（CI）。我们还进行了异质性和敏感性分析，并评估了发表偏倚。共纳入 33 项观察性研究，涉及 234196 名参与者。夏季和 12 月分别作为参考。计算 IRR 显示：IRR 1.05（95%CI 1.04-1.07）、IRR 1.03（95%CI 1.02-1.04）、IRR 1.02（95%CI 1.01-1.03）。12 个月之间没有明显差异。还进行了柯本气候分类的分层分析。虽然存在组间异质性，但预先设定的分层分析和元回归并不能降低这种异质性。我们的荟萃分析显示，总体研究中季节变化很小。按照柯本气候分类分层后，寒冷和炎热月份对 IS 的风险可能都很高。因此，为高危患者的管理提供了环境设置的理由。需要更多具有特定评估的研究来进一步全面调查。
