. 2017 Oct;52(10):955–965. doi: 10.4085/1062-6050-52.7.06

Table 2. .

Injury Rates by Age in Youth Football Players During Games in the 2013 Season

Type of Injury	Age, y										Injury Rate Ratio for Players Aged 11–15 y Versus 5–10 y (95% Confidence Interval)
	5 to 10 (n = 1137)					11 to 15 (n = 961)
	Injury Count	Exposures		Rates		Injury Count	Exposures		Rates
	Injury Count	Total Athlete- Plays	Athlete- Exposures	Per 10 000 Athlete-Plays	Per 1000 Athlete- Exposures	Injury Count	Total Athlete- Plays	Athlete- Exposures	Per 10 000 Athlete-Plays	Per 1000 Athlete- Exposures	Rate per 10 000 Athlete-Plays	Rate per 1000 Athlete- Exposures
All injuries	158	377 800	8848	4.18	17.86	171	322 689	7426	5.30	23.03	1.27 (1.02, 1.57)^a	1.29 (1.04, 1.60)^a
Time-loss injuries only	30	377 800	8848	0.79	3.39	56	322 689	7426	1.74	7.54	2.19 (1.40, 3.41)^a	2.22 (1.43, 3.47)^a
Non–time-loss injuries only	128	377 800	8848	3.39	14.47	115	322 689	7426	3.59	15.49	1.05 (0.82, 1.35)	1.07 (0.83, 1.38)
Concussion only	10	377 800	8848	0.26	1.13	22	322 689	7426	0.68	2.96	2.58 (1.22, 5.44)^a	2.62 (1.24, 5.54)^a

Indicates difference (95% confidence interval did not include 1.00).