title: A case series analysis of mass casualty incidents.
abstract: BACKGROUND
  Mass casualty incidents (MCIs) are infrequent but potentially overwhelming events that can stress the capabilities of even the most organized emergency medical services (EMS) system. The Maryland EMS system has been identified as a pioneer and leader in the field of prehospital emergency care and, as with many states, Maryland's regional preparation for MCIs has been integrated into its overall EMS systems planning.
  
  
  OBJECTIVE
  To determine how successful this integration has been by examining a three-year history of response to MCIs in Maryland.
  
  
  METHODS
  A three-year case series of MCIs in Maryland was obtained from a Nexis national news publications search. These MCIs were cross-referenced with U.S. postal ZIP codes and the U.S. Census Bureau's ZIP code files. They were then mapped and summary statistics were prepared for analysis. Data obtained through the Maryland Health Services Cost Review Commission for all severely injured patients discharged from Maryland hospitals were obtained over the same three-year period for comparison.
  
  
  RESULTS
  Eight MCIs occurred over a three-year period, resulting in a total of 203 injuries. An average of 25.4 +/- 10.7 injuries occurred per MCI. A total of 158 (77.8%) of injuries necessitated ambulance transportation. An average of 3.1 +/- 1.1 hospitals were involved per MCI.
  
  
  CONCLUSIONS
  The Maryland EMS system was effective in responding to MCIs ranging in size from 10 to nearly 40 injuries. Analyzing MCIs that reoccur on a year-to-year basis should figure into the planning process for EMS systems.
authors.affiliation: Department of Biostatistics and Epidemiology, Philadelphia Veterans Affairs Medical Center and University of Pennsylvania School of Medicine, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Branas
authors.forename: R F
authors.initials: RF
authors.lastname: Sing
authors.forename: A D
authors.initials: AD
authors.lastname: Perron
mesh_terms: D002391:Catchment Area, Health; D003625:Data Collection; D004189:Disaster Planning; D004190:Disasters / Q000706:statistics & numerical data*; D004632:Emergency Medical Services / Q000458:organization & administration / Q000706:statistics & numerical data*; D005843:Geography; D006801:Humans; D015994:Incidence; D008396:Maryland / Q000453:epidemiology; D008402:Mass Media; D011159:Population Surveillance; D014947:Wounds and Injuries / Q000453:epidemiology*