Table 1.

Description of the predictors used for LD and HD models for pediatric trauma data

Predictor type	# Predictors	Description	LD	HD
Main effects
ICD-9 codes	1890	International classification of disease, Ninth revision	✗	✓
AIS codes (predots)	349	Abbreviated injury scale codes that includes body region, anatomic structure associated with the injury, and the level of injury	✗	✓
Interactions/combinations
ICD-9, ICD-9	102 284	Co-occurrences of two ICD-9 codes	✗	✓
AIS code, AIS code	20 809	Co-occurrences of two AIS codes	✗	✓
Body region, AIS score	41	Combinations of any of the nine body regions with the injury severity score (between 1 and 6) determined according to the AIS coding scheme	✓	✓
[Body region, AIS score], [Body region, AIS score]	579	Co-occurrences of two [body region, AIS score] combinations	✗	✓