Zhang Honglong, Sun Qiao, Lai Shengjie, Ren Xiang, Zhou Dinglun, Ye Xianfei, Zeng Lingjia, Yu Jianxing, Wang Liping, Yu Hongjie, Li Zhongjie, Lyu Wei, Lan Yajia, Yang Weizhong
Key Laboratory of Surveillance and Early-warning on Infectious Disease, Division of Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
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Zhonghua Yu Fang Yi Xue Za Zhi. 2014 Apr;48(4):265-9.
Providing evidences for further modification of China Infectious Diseases Automated-alert and Response System (CIDARS) via analyzing the outbreak detection performance of Moving Percentile Method (MPM) by optimizing thresholds in different provinces.
We collected the amount of MPM signals, response results of signals in CIDARS, cases data in nationwide Notifiable Infectious Diseases Reporting Information System, and outbreaks data in Public Health Emergency Reporting System of 16 infectious diseases in 31 provinces in Chinese mainland from January 2011 to October 2013. The threshold with the optimal sensitivity, the shortest time to detect outbreak and the least number of signals was considered as the best threshold of each disease in Chinese mainland and in each province.
Among all the 16 diseases, the optimal thresholds of 10 diseases, including dysentery, dengue, hepatitis A, typhoid and paratyphoid, meningococcal meningitis, Japanese encephalitis, scarlet fever, leptospirosis, hepatitis, typhus in country level were the 90(th) percentile (P90), which was the same as provincial level for those diseases.For the other 6 diseases, including other infectious diarrhea, influenza, acute hemorrhagic conjunctivitis, mumps, rubella and epidemic hemorrhagic fever, the nationwide optimal thresholds were the 80th percentile (P80), which was different from that by provinces for each disease. For these 6 diseases, the number of signals generated by MPM with the optimal threshold for each province was decreased by 23.71% (45 557), 15.59% (6 124), 14.07% (1 870), 9.44% (13 881), 8.65% (1 294) and 6.03% (313) respectively, comparing to the national optimal threshold, while the sensitivity and time to detection of CIDARS were still the same.
Optimizing the threshold by different diseases and provinces for MPM in CIDARS could reduce the number of signals while maintaining the same sensitivity and time to detection.
通过分析移动百分位数法（MPM）在不同省份优化阈值后的疫情监测性能，为进一步完善中国传染病自动预警与响应系统（CIDARS）提供依据。
收集2011年1月至2013年10月中国大陆31个省份16种传染病在全国法定传染病报告信息系统中的病例数据、公共卫生应急报告系统中的疫情数据、CIDARS中MPM信号数量及信号响应结果。将灵敏度最佳、疫情发现时间最短且信号数量最少的阈值视为中国大陆及各省份每种疾病的最佳阈值。
16种疾病中，痢疾、登革热、甲型肝炎、伤寒和副伤寒、流行性脑脊髓膜炎、流行性乙型脑炎、猩红热、钩端螺旋体病、肝炎、斑疹伤寒这10种疾病在国家层面的最佳阈值为第90百分位数（P90），在省级层面也是如此。对于其他6种疾病，包括其他感染性腹泻、流感、急性出血性结膜炎、腮腺炎、风疹和流行性出血热，全国最佳阈值为第80百分位数（P80），各省份每种疾病的该阈值有所不同。对于这6种疾病，与国家最佳阈值相比，各省份采用最佳阈值的MPM产生的信号数量分别减少了23.71%（45557个）、15.59%（6124个）、14.07%（1870个）、9.44%（13881个）、8.65%（1294个）和6.03%（313个），而CIDARS的灵敏度和发现时间保持不变。
针对CIDARS中的MPM，按不同疾病和省份优化阈值可在保持灵敏度和发现时间不变的情况下减少信号数量。
