Meng Lei, Wang Xin-hua, Li Juan-sheng, Ren Xiao-wei, Li Hong-yu, Hu Xiao-bin, Yang Xiao-ting, Qin Lin-yuan, Chen Jian-hua, Bai Ya-na
Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2012 Nov;33(11):1155-8.
To understand the epidemiological trend on the number of influenza-like cases and to explore the feasibility of early warning systems of influenza in Gansu province.
Based on data from the influenza sentinel surveillance program, a sequence chart was used to analyze the epidemiological trend on the number of influenza-like illness (ILI) cases. Both control chart and mobile percentile method were used to select the threshold of premium alert for the ILI of sentinel surveillance program. Warning effects were assessed by statistical model.
The prevalence of influenza were both low in 2007 and 2008. Alert thresholds for ILI of Sentinel surveillance was built. The thresholds were higher alert in winter, but lower in summer. Both Seasonal Exponential Smoothing Model and Multiplicative Seasonal ARMA Model (1, 1, 1) (0, 1, 0) were used to dynamically predict the weekly percentage of outpatient visits for influenza-like illness (ILI%) of 2011. The concordance rates (predicted = actual) were 100% for both of them. According to the RMSE values, the dynamically predicted effect of the seasonal exponential smoothing model was superior to ARIMA.
Dynamic prediction on the number of influenza-like cases could reflect the epidemiological trend of influenza in Gansu province, but with some limitations.
了解甘肃省流感样病例数的流行趋势，探索流感早期预警系统的可行性。
基于流感哨点监测项目的数据，用序列图分析流感样疾病（ILI）病例数的流行趋势。采用控制图和移动百分位数法选择哨点监测项目ILI的预警阈值。通过统计模型评估预警效果。
2007年和2008年流感患病率均较低。建立了哨点监测ILI的预警阈值。这些阈值在冬季较高，夏季较低。使用季节性指数平滑模型和乘法季节性自回归滑动平均模型（1,1,1）（0,1,0）动态预测2011年流感样疾病门诊就诊率（ILI%）的每周百分比。两者的一致性率（预测=实际）均为100%。根据均方根误差值，季节性指数平滑模型的动态预测效果优于自回归积分滑动平均模型。
对流感样病例数的动态预测可以反映甘肃省流感的流行趋势，但存在一定局限性。
