Table I.

Match variables

Demographics	Procedures (ICD-9-based, all yes/no)	Injury Type (Barell-based, all yes/no)
Age (years)	Arterial catheter placement	Abuse/Assault
Admission year	Chest tube placement	Amputation
Discharge year	Closed reduction/Internal fixation	Blood Vessel
Gender	Closed reduction/No fixation	Burns
Insurance	CVC placement	Dislocation
Race/Ethnicity	Craniotomy/Craniectomy	Fracture
Hospital Course	Gastrostomy tube placement	Internal Organ
ICU admission (yes/no)	ICP Monitor placement	Nerve
Hospital LOS (days)	Intubation	Open wound
Discharge disposition	Mechanical ventilation < 96 hours	Sprain/Strain
Hospital (estimated iteratively)	Mechanical ventilation ≥ 96 hours	System wide and late effects
Injury mechanism (E code-based)	Open reduction/Internal fixation	Abuse/Assault
ISS (ICDMAP-90)	Open reduction/No fixation	Amputation
AIS (ICDMAP-90)	Tracheostomy
Head	Splint placement
Face	Wound closure
Neck	Wound debridement
Chest
Abdomen/Pelvis
Spine
Upper Extremity
Lower Extremity
External, Burns, Other