X-12-ARIMA方法在伤寒发病趋势分析中的应用

The application of X-12-ARIMA model in analysis on incidence trend of typhoid

目的研究X-12-ARIMA方法在伤寒/副伤寒疫情分析中的作用。方法应用X-12-ARIMA方法对浙江省2005—2013年伤寒/副伤寒的月度发病数据分别进行长期趋势、季节周期和随机波动分析,解析原始发病数据中存在的内在特征和变化规律。结果 2005—2013年季节因子波动幅度呈逐年缩小趋势;浙江省2007年9月后,伤寒/副伤寒的整体发病水平呈下降趋势;2008年后,伤寒/副伤寒年度发病高峰月由原来的8月提前至7月;不规则项能较好反映暴发疫情。结论通过X-12-ARIMA方法分解的伤寒/副伤寒发病数据,其长期趋势明显、季节变化规律清晰、随机波动信息具有重要价值。

Objective To study the function of X -1 2 -ARIMA model in analysis on incidence trend of typhoid. Methods Secular trend,seasonal periodicity and random fluctuations of the monthly morbidity data in Zhejiang province from 2005 to 201 3 were analyzed by X -1 2 -ARIMA model.Results The seasonal fluctuation showed a narrowing trend year by year during 2005 to 201 3.After September,2007,the incidence of typhoid showed a downward trend.After 2008,the annual peak of incidence changed from August to July.The irregular factor may well represent the outbreak. Conclusion The X -1 2 -ARIMA model showed clear secular trend and seasonal periodicity,and the random fluctuation was of great value.