Table 1.

Risk, RR, and adjusted RR by age

Age	Number of athletes	Number of concussions	Risk (%)	RR	Adjusted RRa (95% CI)	ARR p-value
13	512	40	7.8	Reference	Reference	NA
14	2,352	178	7.6	0.97 (0.70, 1.35)	0.82 (0.59, 1.15)	0.248
15	2,477	363	14.7	1.88 (1.37, 2.56)	1.53 (1.11, 2.11)	0.009**
16	2,470	309	12.5	1.60 (1.17, 2.19)	1.32 (0.96, 1.83)	0.089*
17	1,944	255	13.1	1.68 (1.22, 2.31)	1.39 (1.01, 1.93)	0.046*
18	579	105	18.1	2.32 (1.65, 3.28)	1.91 (1.35, 2.71)	0.0003**

^aAdjusted for sex and sport.

*p < 0.05. **p < 0.01.