Document Analysis of Correlation between Climate and Stroke

Aim: The aim of the research is to determine characteristic of the correlation between climate and stroke through the analysis of relevant documents. Methods: We found 115 researches of temperature and season on stroke mortality/incidence and these were categorized according to location, meteorology, date span, data source and research sites’ latitudes. We divided the globe into 5 temperature zones based on latitude ranges: 0 - 10, 10 - 23.5, 23.5 - 40, 40 - 50, and >50 degrees, and allotted a zone to each country. Stroke mortality by five temperature zones was calculated per 100,000 people. Results: 70% of the researches came from latitudes greater than 40 degrees with 92% of researches located in Europe, USA, and Asia. The mortality range was 42 - 63 per 105 individuals within latitudes 0 - 40 degrees. In latitudes 40 - 66.5 degrees, a linear upward trend (y = 69.82x − 22.823, R2 = 0.99) was noticed. More than 75% of the research reports indicated a negative correlation between climate and stroke, and the proportion was almost 6 and 7 times greater than that of the fluctuation and non-correlation, respectively. The most frequently used research methods were regression analysis and time series analysis. Conclusion: All of the research results confirmed that lower temperature is associated with higher mortality and incidence of stroke, while higher latitude is correlated with higher stroke mortality, consistent with the temperature zones.