title: A novel methodology to characterize interfacility transfer strategies in a trauma transfer network.
abstract: More than half of severely injured patients are initially transported from the scene of injury to nontrauma centers (NTCs), with many requiring subsequent transfer to trauma center (TC) care. Definitive care in the setting of severe injury is time sensitive. However, transferring severely injured patients from an NTC is a complex process often fraught with delays. Selection of the receiving TC and the mode of interfacility transport both strongly influence total transfer time and are highly amenable to quality improvement initiatives.
  
  
  
  We analyzed transfer strategies, defined as the pairing of a destination and mode of transport (land vs. rotary wing vs. fixed wing), for severely injured adult patients. Existing transfer strategies at each NTC were derived from trauma registry data. Geographic Information Systems network analysis was used to identify the strategy that minimized transfer times the most as well as alternate strategies (+15 or +30 minutes) for each NTC. Transfer network efficiency was characterized based on optimality and stability.
  
  
  
  We identified 7,702 severely injured adult patients transferred from 146 NTCs to 9 TCs. Nontrauma centers transferred severely injured patients to a median of 3 (interquartile range, 1-4) different TCs and utilized a median of 4 (interquartile range, 2-6) different transfer strategies. After allowing for the use of alternate transfer strategies, 73.1% of severely injured patients were transported using optimal/alternate strategies, and only 40.4% of NTCs transferred more than 90% of patients using an optimal/alternate transfer strategy. Three quarters (75.5%) of transfers occurred between NTCs and their most common receiving TC.
  
  
  
  More than a quarter of patients with severe traumatic injuries undergoing interfacility transport to a TC in Ontario are consistently transported using a nonoptimal combination of destination and mode of transport. Our novel analytic approach can be easily adapted to different system configurations and provides actionable data that can be provided to NTCs and other stakeholders.
  
  
  
  Therapeutic study, level IV.
authors.affiliation: From the Division of General Surgery, Department of Surgery (D.G., H.T., A.B.N.), University of Toronto, Ontario, Canada; Sunnybrook Research Institute (D.G., B.H., A.A., H.T., G.R., A.B.N.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; Interdepartmental Division of Critical Care (B.H., A.S.A., J.M.S., J.R.), University of Toronto, Ontario, Canada; Child Health Evaluative Sciences (K.L.), The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Geography and Planning (K.L), University of Toronto, Ontario, Canada; Ornge Transport Medicine (R.D.M., H.T.), Mississauga, Ontario, Canada; Division of Emergency Medicine, Department of Medicine (R.D.M.), University of Toronto, Ontario, Canada; Toronto Western Research Institute (J.M.S.), Toronto Western Hospital, Toronto, Ontario, Canada; and Department of Internal Medicine (T.J.I.), University of Michigan Medical School, Ann Arbor, Michigan.
authors.forename: David
authors.initials: D
authors.lastname: Gomez
authors.forename: Barbara
authors.initials: B
authors.lastname: Haas
authors.forename: Kristian
authors.initials: K
authors.lastname: Larsen
authors.forename: Aziz S
authors.initials: AS
authors.lastname: Alali
authors.forename: Russell D
authors.initials: RD
authors.lastname: MacDonald
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Singh
authors.forename: Homer
authors.initials: H
authors.lastname: Tien
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Iwashyna
authors.forename: Gordon
authors.initials: G
authors.lastname: Rubenfeld
authors.forename: Avery B
authors.initials: AB
authors.lastname: Nathens
mesh_terms: D000328:Adult; D000552:Ambulances; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D009864:Ontario / Q000453:epidemiology; D010360:Patient Transfer / Q000458:organization & administration*; D058996:Quality Improvement; D012042:Registries; D013997:Time Factors; D014193:Trauma Centers; D014947:Wounds and Injuries / Q000453:epidemiology*