湖北省潜江市手足口病疫情不同预警模型效果比较

Efficacy of different models for hand-foot-mouth disease warning in Qianjiang city of Hubei province: a simulated comparative analysis

目的探究适合湖北省潜江市手足口病的预警模型并比较预警功效,为自动预警提供技术支持。方法利用湖北省潜江市2013年4月1日—2014年3月31日的手足口病数据和模拟暴发数据对Shewhart模型、移动平均模型(MA)、指数加权移动平均(EWMA)、累计和控制图(CUSUM)以及早期异常探测系统(EARS'C1、C2、C3)预警模型进行比较。通过改变预警阈值水平,比较各预警模型在不同模拟暴发数据下的约登指数和平均检出时间(DT)。结果对于不同参数的模拟暴发数据,暴发的强度越大,预警模型的约登指数越高,平均DT越短;而暴发的持续时间越长,预警模型的约登指数越高,平均DT却有所延长。综合9种不同强度及持续时间的模拟暴发评价结果,发现在预警阈值为0.5时各模型功效最优。此时,Shewhart的约登指数和平均DT为0.57、1.12 d;MA为0.58、2.62 d;EWMA为0.44、3.70 d;CUSUM为0.46、3.56 d;EARS'C1为0.59、2.43 d;EARS'C2为0.57、2.47 d;EARS'C3为0.55、2.20 d。结论 Shew hart模型更适合于潜江地区手足口病的预警。

Abstract： Objective To explore appropriate models for making early warning of hand-foot-mouth disease （HFMD） in Qianjiang city of Hubei province and to provide technical support for the automatic warning of disease sur- veillance system. Methods Data on HFMD from April 1,2013 to December 31,2014 in Qianjiang and simulated out- breaks were used to test the warning efficacy of Shewhart, moving average （MA）, exponential weighted moving average （ EWMA）, cumulative sums （CUSUM） and early abreation reporting system （ EARS＇ C1, C2, C3 ） time-series models. The warning efficacy of each warning model was compared using average detection time and the Youden＇s index with different simulated outbreak data. Results With an increase in intensity of simulated outbreak, the Youden＇ s index of warning model increases but the average detection time decreases; the Youden＇s index and average detection time in- crease with the increment of duration of simulated outbreaks. Based on comprehensive analyses on 9 patterns of simulated outbreaks with various intensity and duration, every model could reach the best efficacy when adopting 0. 5 as the warning threshhold. The Youden＇s index and the average detection time were 0. 57 and 1.12 days for Shewhart model,0. 58 and 2. 62 days for MA,0.44 and 3.70 days for EWMA,0. 46 and 3.56 days for CUSUM,0. 59 and 2.43 days for EARS＇C1, 0. 57 and 2. 47 days for EARS＇C2, and 0. 55 and 2. 20 days for EARS＇C3, respectively. Conclusion Among the seven warning models evaluated, Shewhart model is more appropriate for early warning of HFMD in Qianjiang city.