Hierarchical filtering can furnish practical, canonical alert criteria applied to algorithm alerts. As circumstances change, users may reconfigure for increased sensitivity or altered coverage with ESSENCE customization tools. The planned addition of new data elements (laboratory/micro, pharmacy and radiology) will further refine alerting. These refinements can increase detection/response capability by focusing attention on signals of interest with a reasonable alert burden. Novel approach to statewide biosurveillance using emergency medical services (EMS) information