A Double-Scan Statistic for Clusters of Two Types of Events
开发了一种扫描型统计量，用于衡量两类事件随时间聚类的异常程度，允许两类事件之间存在滞后效应，并应用于7年期间多个县和性别/种族组合的杀人/自杀聚类数据。
Abstract We develop a scan-type statistic to measure the unusualness of the clustering of two types of events over time. The statistic allows for a lagged effect between the two types of events. We derive the expected number of nonoverlapping clumps of clusters under retrospective and prospective chance models of no association. Results are derived and approaches are given to handle both uniform and more general distributions of events over time. We investigate the power of the statistic against an alternative where the observed data is a mixture of linked and unassociated clusters. The statistic is applied to data on homicide/suicide clusters over a 7-year period for several counties and several sex/race combinations.