甘肃省2008—2013年传染病自动预警系统时间模型运行结果分析

Performance efficiency of temporal model in China Infectious Diseases Automated-Alert and Response System in Gansu province,2008-2013

目的分析甘肃省2008—2013年传染病自动预警系统时间模型的运行结果,评价该预警系统的灵敏性和实用性,为进一步优化预警阈值提供参考依据。方法收集甘肃省2008年1月—2013年12月传染病预警数据,分析传染病预警系统时间模型产生的预警信号数量及响应结果,并比较不同病种和地区预警阈值调整前后的预警结果。结果甘肃省2008—2013年传染病自动预警系统共发出预警信号39 940条,报告病例数与预警信号数比值为9.01:1,疑似事件信号数占预警信号数的1.57%,预警信号阳性率为0.64%;发出预警信号最多的病种为痢疾、其他感染性腹泻、流行性腮腺炎,占所有预警信号的63.17%;在预警阈值调整后,预警系统灵敏度由70.59%下降至39.62%,预警信号阳性率由0.88%下降至0.34%,流行性感冒、流行性腮腺炎、风疹、手足口病、其他感染性腹泻、痢疾、甲肝、急性出血性结膜炎预警阳性率下降;预警信号共覆盖甘肃省14个市州86个县区,响应时间中位数为0.84 h;在预警阈值调整后,仅兰州市、嘉峪关市预警信号阳性率上升,所有市州信号响应时间中位数均较调整前缩短。结论甘肃省2008—2013年传染病自动预警系统运行稳定,预警系统阈值调整后预警效果欠佳,今后将根据不同病种和地区的具体情况优化阈值,减少假阳性预警,进一步提高预警系统的灵敏度和特异度。

Objective To analyze the performance efficiency of temporal model in China Infectious Diseases Auto- mated-Alert and Response System（ CIDARS）in Gansu province from 2008 to 2013 and to evaluate the sensitivity and practicability of CIDARS. Methods Data on infectious disease automated alert signals form CIDARS in Gansu province from January 2008 through December 2013 were collected and analyzed with descriptive methods and the effect of alert threshold adjustment in temporal model in CIDARS was assessed for different areas and diseases. Results Totally 39 940 early-warning signals were issued by CIDARS;the ratio between the number of reported infectious disease cases and the number of early-warning signals was 9.01-1 ;the suspected incident signals accounted for 1.57% of all the early-warning signals;the positive rate of early-warning signals was 0. 64%. The majority of the warning signals were the inci- dents of dysentery, other infectious diarrhea, and mumps, accounting for 63.17% of all the warning signals. The early-warning signals involved 86 counties or districts of 14 prefectures in the province and the median response time for the signals was 0. 84 hour. After the adjustment of early-warning threshold in December 2010, the sensitivity of CIDARS dropped from 70. 59% to 39. 62% and the positive rate dropped from 0. 88% to 0. 34%. The positive rate declined for the early-warning signals of influenza, mumps, rubella, hand foot and mouth disease, other infectious diarrhea, dysentery, hepatitis A,and acute hemorrhagic conjunctivitis;whereas the positive rate increased for the signals for the incidents in Lanzhou and Jiayuguan municipality. The median response time shortened for all the early-warning signals. Conclusion The performance of CIDARS in Gansu province was stable between 2008 and 2013, but the adjustment of early-warning threshold in CIDARS showed no good results, suggesting that the threshold still needs to be optimized for the improvement of sensitivity and specificity of CIDARS.