Table 3. School-level risk factors for sports-related concussion, CARE CSC, 2014/15 to 2018/19 academic years.

	Univariate				Multivariate
	Risk Ratio (95% CI)		P-value relative to ref.	Overall P-value	Risk Ratio (95% CI)		P-value relative to ref.	Overall P-value
All Sports-Related Concussions (Competition and Practice Combined)
Sport Risk Index
Low	1	(reference)			1	(reference)
Medium	4.17	(3.35, 5.20)	< .0001	< .0001	4.18	(3.33, 5.25)	< .0001	< .0001
High	5.66	(4.25, 7.53)	< .0001		5.66	(4.23, 7.59)	< .0001
Division
D1	1.52	(0.90,2.59)	0.1139	0.1734	1.63	(0.90, 2.94)	0.1040	0.1497
D2	0.99	(0.39, 2.47)	0.9771		1.05	(0.42, 2.61)	0.9097
D3	1	(reference)			1	(reference)
School Type
Civilian	1	(reference)			1	(reference)
Military	1.47	(0.58, 3.72)	0.4047	0.3975	1.41	(0.73, 2.73)	0.2983	0.2886
Competition Concussions Only
Sport Risk Index
Low	1	(reference)			1	(reference)
Medium	5.60	(4.03, 7.78)	< .0001	< .0001	5.60	(3.94, 7.96)	< .0001	< .0001
High	10.61	(8.07, 13.96)	< .0001		10.63	(7.91, 14.28)	< .0001
Division
D1	1.15	(0.51, 2.61)	0.7205	0.8312	1.24	(0.57, 2.73)	0.5706	0.7099
D2	0.96	(0.35, 2.67)	0.9428		1.03	(0.40, 2.67)	0.9433
D3	1	(reference)			1	(reference)
School Type
Civilian	1	(reference)			1	(reference)
Military	1.61	(0.81, 3.20)	0.1637	0.1526	1.53	(0.88, 2.66)	0.1225	0.1104
Practice Concussions Only
Sport Risk Index
Low	1	(reference)			1	(reference)
Medium	3.83	(3.05, 4.82)	< .0001	< .0001	3.83	(3.01, 4.88)	< .0001	< .0001
High	4.41	(3.17, 6.13)	< .0001		4.42	(3.16, 6.18)	< .0001
Division
D1	1.99	(1.27, 3.11)	0.0041	0.0049	2.09	(1.16, 3.77)	0.0165	0.0215
D2	1.11	(0.43, 2.88)	0.8177		1.18	(0.43, 3.20)	0.7374
D3	1	(reference)			1	(reference)
School Type
Civilian	1	(reference)			1	(reference)
Military	1.44	(0.49, 4.20)	0.4952	0.4895	1.39	(0.70, 2.79)	0.3335	0.3244