title: A novel approach to multihazard modeling and simulation.
abstract: OBJECTIVE
  To develop and apply a novel modeling approach to support medical and public health disaster planning and response using a sarin release scenario in a metropolitan environment.
  
  
  METHODS
  An agent-based disaster simulation model was developed incorporating the principles of dose response, surge response, and psychosocial characteristics superimposed on topographically accurate geographic information system architecture. The modeling scenarios involved passive and active releases of sarin in multiple transportation hubs in a metropolitan city. Parameters evaluated included emergency medical services, hospital surge capacity (including implementation of disaster plan), and behavioral and psychosocial characteristics of the victims.
  
  
  RESULTS
  In passive sarin release scenarios of 5 to 15 L, mortality increased nonlinearly from 0.13% to 8.69%, reaching 55.4% with active dispersion, reflecting higher initial doses. Cumulative mortality rates from releases in 1 to 3 major transportation hubs similarly increased nonlinearly as a function of dose and systemic stress. The increase in mortality rate was most pronounced in the 80% to 100% emergency department occupancy range, analogous to the previously observed queuing phenomenon. Effective implementation of hospital disaster plans decreased mortality and injury severity. Decreasing ambulance response time and increasing available responding units reduced mortality among potentially salvageable patients. Adverse psychosocial characteristics (excess worry and low compliance) increased demands on health care resources. Transfer to alternative urban sites was possible.
  
  
  CONCLUSIONS
  An agent-based modeling approach provides a mechanism to assess complex individual and systemwide effects in rare events.
authors.affiliation: Department of Emergency Medicine, Bellevue Hospital Center, 462 First Ave, Room A345A, New York, NY 10016, USA. Silas.Smith@nyumc.org
authors.forename: Silas W
authors.initials: SW
authors.lastname: Smith
authors.forename: Ian
authors.initials: I
authors.lastname: Portelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Narzisi
authors.forename: Lewis S
authors.initials: LS
authors.lastname: Nelson
authors.forename: Fabian
authors.initials: F
authors.lastname: Menges
authors.forename: E Dianne
authors.initials: ED
authors.lastname: Rekow
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Mincer
authors.forename: Bhubaneswar
authors.initials: B
authors.lastname: Mishra
authors.forename: Lewis R
authors.initials: LR
authors.lastname: Goldfrank
mesh_terms: D002619:Chemical Warfare Agents / Q000009:adverse effects*; D002959:Civil Defense / Q000379:methods*; D003198:Computer Simulation; D004189:Disaster Planning / Q000379:methods*; D004630:Emergencies / Q000453:epidemiology* / Q000523:psychology; D004636:Emergency Service, Hospital; D004781:Environmental Exposure / Q000009:adverse effects; D015438:Health Behavior; D006801:Humans; D008962:Models, Theoretical; D009026:Mortality; D016016:Proportional Hazards Models; D012524:Sarin / Q000009:adverse effects*; D013315:Stress, Psychological / Q000209:etiology; D014218:Triage
chemical_list: D002619:Chemical Warfare Agents; D012524:Sarin