Myint Phyo K, Vowler Sarah L, Woodhouse Peter R, Redmayne Oliver, Fulcher Robert A
Department of Medicine for the Elderly, Norfolk and Norwich University Hospital, Norwich, UK.
Neuroepidemiology. 2007;28(2):79-85. doi: 10.1159/000098550. Epub 2007 Jan 17.
Several studies have examined the incidence and mortality of stroke in relation to season. However, the evidence is conflicting partly due to variation in the populations (community vs. hospital-based), and in climatic conditions between studies. Moreover, they may not have been able to take into account the age, sex and stroke type of the study population. We hypothesized that the age, sex and type of stroke are major determinants of the presence or absence of winter excess in morbidity and mortality associated with stroke.
We analyzed a hospital-based stroke register from Norfolk, UK to examine our prior hypothesis. Using Curwen's method, we performed stratified sex-specific analyses by (1) seasonal year and (2) quartiles of patients' age and stroke subtype and calculated the winter excess for the number of admissions, in-patient deaths and length of acute hospital stay.
There were 5,481 patients (men=45%). Their ages ranged from 17 to 105 years (median=78 years). There appeared to be winter excess in hospital admissions, deaths and length of acute hospital stay overall accounting for 3/100,000 extra admissions (winter excess index of 3.4% in men and 7.6% in women) and 1/100,000 deaths (winter excess index of 4.7 and 8.6% in women) due to stroke in winter compared to non-winter periods. Older patients with non-haemorrhagic stroke mainly contribute to this excess. If our findings are replicated throughout England and Wales, it is estimated that there are 1,700 excess admissions, 600 excess in-patient deaths and 24,500 extra acute hospital bed days each winter, related to stroke within the current population of approximately 60 million.
Further research should be focused on the determinants of winter excess in morbidity and mortality associated with stroke. This may subsequently reduce the morbidity and mortality by providing effective preventive strategies in future.
多项研究探讨了中风的发病率和死亡率与季节的关系。然而,证据相互矛盾,部分原因是研究人群(社区人群与医院人群)存在差异,且各研究之间的气候条件也有所不同。此外,这些研究可能未能考虑研究人群的年龄、性别和中风类型。我们假设年龄、性别和中风类型是与中风相关的发病率和死亡率冬季超额情况存在与否的主要决定因素。
我们分析了英国诺福克郡一家医院的中风登记数据,以检验我们之前的假设。使用柯文方法,我们按(1)季节年份以及(2)患者年龄四分位数和中风亚型进行了分层性别特异性分析,并计算了入院人数、住院死亡人数和急性住院时间的冬季超额情况。
共有5481名患者(男性占45%)。他们的年龄在17岁至105岁之间(中位数为78岁)。总体上,冬季的医院入院人数、死亡人数和急性住院时间似乎存在超额情况,与非冬季相比,冬季因中风导致的额外入院人数为每10万人中有3例(男性冬季超额指数为3.4%,女性为7.6%),额外死亡人数为每10万人中有1例(女性冬季超额指数为4.7%和8.6%)。非出血性中风的老年患者是造成这种超额情况的主要原因。如果我们的研究结果在英格兰和威尔士得到重复验证,据估计每年冬季与中风相关的额外入院人数为1700例,额外住院死亡人数为600例,额外急性住院天数为24500天,当前英格兰和威尔士人口约为6000万。
进一步的研究应聚焦于与中风相关的发病率和死亡率冬季超额情况的决定因素。这可能随后通过在未来提供有效的预防策略来降低发病率和死亡率。