前瞻性时空扫描统计量方法在手足口病暴发预警中的参数筛选

Parameters setting on hand-foot-and-mouth cluster detection in prospective space-time scan statistics

目的根据手足口病的流行特点,比较和筛选时空扫描统计量方法较好的预警参数,从而更好的应用于手足口病暴发早期探测预警。方法以真实的暴发事件作为参考数据,灵敏度、探测时间间隔和阳性预测值为评价指标,采用前瞻性时空扫描统计量方法,利用不同时空参数对山东省青岛市2009年6月手足口病病例数据逐日模拟预警探测,比较4种参数不同设定值的24种预警效果。结果时间窗口设置为3天和基线设置为最近21天的病例数据进行时空扫描统计量预警运算,具有最优的预警效果。候选聚集区域范围的设定对预警效果无统计显著性。结论采用前瞻性时空扫描统计量进行传染病暴发预警时,具有最优的参数,但相同的传染病在不同区域可能有不同的预警参数,下一步应该根据相同传染病在不同地区筛选最优参数方案。

Objective For better application of prospective space-time scan statistics method to early warning of hand-foot-mouth disease（ HFMD） outbreak,according to its epidemiological characteristics,different parameters for prospective space-time scan statistics method was used. Methods The cases and real outbreaks reported by Qingdao in June2009 were recruited as data source. Sensitivity and positive prediction ratio and detection time interval were taken as evaluation indice,the prospective space-time scan statistic was tested by mimicking daily prospective analyses of HFMD data. We compared the twenty-four groups of performances under four kinds of different parameters. Results Taking time window of three days and the length baseline of cases in the last 21 days. The best performance was obtained. Simultaneously,the setting parameters of the candidate areas had no statistically significant effect on prospective space-time scan statistics method in early warning. Conclusions Application of prospective space-time scan statistics method to early warning of infectious disease outbreak helps with choose of different parameters of infectious disease in order to get the best results. The best parameters based on the different regions of the same infectious disease should be chosen.