前瞻性时空扫描统计量在传染病预警中的基线选择研究

目的探索将前瞻性时空扫描统计量运用于传染病预警中适宜基线的选择方法。方法根据当年流行情况选择发病高峰时段结合固定长度基线以及可变长度基线运用前瞻性时空扫描统计量进行模拟实时预警分析,通过不同长度基线的结果比较,探索不同基线在不同流行状况的适用差异并寻找选择适当基线的方法。结果固定长度基线产生了18个信号,而采用可变长度基线只纳入高峰期数据的预警则产生了28个信号,且这28个信号中完全包括了固定长度基线产生的18个信号。其中2009年4月17日及18日固定长度基线的1号信号均被以可变长度基线的时空扫描统计量分为3个较小但发病率更高的信号。结论在发病高峰期选择可变长度基线能够更加精确地区分聚集性区域,并且在经过排除重叠信号后,可以得到更高的探测效能。

Study on the baseline selection of the prospective space-time scan statistic model in early warning of infectious diseases

OBJECTIVE To research on how to choose a proper baseline of early warning for infectious diseases with the prospective space-time scan statistic model.METHODS A flexible length baseline was built which contained only the days at the same incidence level.The daily prospective analyses were also simulated to find out the difference between different baselines.RESULTS 28 clusters were detected with the flexible length baseline while all the 18 clusters with the fixed length baseline were contained.The first cluster detected in 2009.4.17-2009.4.18 with fixed length baseline was distinguished to 3 smaller clusters with a higher incidence rate.CONCLUSION The flexible baseline presents greater detection power and better identification than the fixed length baseline during period with high incidence rate.