Definition of Variables

Variable	Definition
Command and Control:
Time zero	Time of initial notification call. Times measured from this point (minutes).
Units activated	Number, type and time of providers dispatched to respond to the scene.
Time to scene safety	Time until completion of scene inspection and safety declaration.
Time to scene command	Time until a visible command structure was established at the scene.
Time to scene staging	Time until distinct treatment staging area(s) were established.

Pre-hospital Care:
Units responding	Service and number of vehicles and providers arriving at the scene.
Time to arrival	Time until scene arrival for each responding unit and provider.
Time to triage	For each victim, time until initial assessment by a pre-hospital provider.
Time to first move	For each victim, time until transport from initial location to a staging area.
Time to transport	Time until each victim was removed from the scene.
Time to treatment	For each victim, time until the first critical action was performed.
Triage categories:
Non-urgent	Ambulatory patient with minor or no injuries and stable vital signs
Urgent	Significant injuries but no immediate threat to life, stable vital signs.
Emergent	Unstable vital signs or potentially life-threatening injuries.
Unsalvageable	Dead or non-survivable injuries.

Pre-hospital Critical Actions:
Manually opening the airway
Placing patient in rescue position
Administration of oxygen
Ventilation with bag-valve-mask device
Initial control of hemorrhage
Initiation of an intravenous line
Immobilization of spine and/or extremities
Application of wound dressings

Hospital Care:
Time to patient arrival	For each victim, time until arrival at receiving hospital triage area.
Time to hospital triage	For each victim, time until an initial triage assessment.
Time to patient treatment	Time until the first hospital based critical action.
Time to disposition	Time until disposition decision from the triage area (OR, admit, discharge).
Disposition	Admit to hospital, transfer to operating room or discharge.
Hospital Critical Actions:
Manually opening the airway
Administration of oxygen
Ventilation with a bag-valve-mask device
Endotracheal intubation
Needle decompression of pneumothorax
Thoracostomy tube placement
Control of hemorrhage
Initiation of an intravenous line
Immobilization of spine or extremities
Wound care
Administration of analgesics
Administration of antibiotics or other medication

System integration:
Time to plan activation	Time to activation of system-wide disaster plan.
Time to inter-agency command	Time to inter-agency communications and command structure
Time to hospital notification	Time the receiving hospital was notified of a disaster situation.
Public Safety Response	Affiliation, arrival time, number of responding officers