Season specific incidence pattern of stroke indicated with circular distribution method

Objective To understand the season specific incidence pattern of stroke in Tongxiang. Methods The information of 10 565 stroke patients from 2010 to 2014 were collected through Zhejiang chronic disease surveillance system, circular distribution method was used to analyze the seasonal stroke incidence. Results Two types of stroke had obvious seasonality, ischemic stroke mainly occurred in summer, hemorrhagic stroke mainly occurred in winter. From 2010 to 2013, the annual incidence of ischemic stroke had no obvious central tendency, but the overall incidence had, the mean angel of total was 160.949, equivalent to June 12 (Z=7.061, P0.001). However, the annual incidence of hemorrhagic stroke had obvious central tendency except for 2014, the mean angel of total was 17.708, equivalent to January 18 (Z=44.998, P0.001). Conclusion The incidence of stroke in Tongxiang had obvious seasonality. It is necessary to take appropriate preventive and treatment measures to reduce the incidence of stroke and disability.