Table 1.

Conceptual Categories of Model Variables

Category	Specific variables
Psychosocial factors	Subjective reporting norms (coach, teammates, parents, students)
Demographic characteristics	Highest level of parental educational attainment (mother, father); race/ethnicity; scholarship status
Exposure modifiers	Primary playing position (line vs. skill); year on team; total years of full-contact football; total career concussions (used in injury model only); total career non-concussion injuries (used in concussion model only)