Table 5.

Anterior Cruciate Ligament Injury by Competition Period, Sport, Sex, and Season Segment^a

Variable	Before Halftime			Halftime or Later			Incidence Rate Ratio Versus Before Halftime (95% CI)
	No.	AEs	Rate per 10 000 AEs (95% CI)	No.	AEs	Rate per 10 000 AEs (95% CI)
All injuries
Sport
Basketball	72	400 589	1.80 (1.38, 2.21)	76	400 589	1.90 (1.47, 2.32)	1.06 (0.76, 1.46)
Lacrosse	32	138 122	2.32 (1.51, 3.12)	32	138 122	2.32 (1.51, 3.12)	1.00 (0.61, 1.63)
Soccer	38	373 576	1.02 (0.69, 1.34)	41	373 576	1.10 (0.76, 1.43)	1.08 (0.69, 1.68)
Sex
Males	47	437 826	1.07 (0.77, 1.38)	44	437 826	1.00 (0.71, 1.30)	0.94 (0.62, 1.41)
Females	95	474 461	2.00 (1.60, 2.40)	105	474 461	2.21 (1.79, 2.63)	1.11 (0.84, 1.46)
Season segment
Early regular seasonb	29	108 645	2.67 (1.70, 3.64)	11	108 645	1.01 (0.41, 1.61)	0.38 (0.19, 0.76)c
Middle regular seasonb	13	90 702	1.43 (0.65, 2.21)	14	90 702	1.54 (0.73, 2.35)	1.08 (0.51, 2.29)
Late regular seasonb	10	106 679	0.94 (0.36, 1.52)	24	106 679	2.25 (1.35, 3.15)	2.40 (1.15, 5.02)c
Postseasonb	3	20 176	1.49 (0.00, 3.17)	2	20 176	0.99 (0.00, 2.37)	0.67 (0.11, 3.99)
Noncontact
Sport
Basketball	47	400 589	1.17 (0.84, 1.51)	50	400 589	1.25 (0.90, 1.59)	1.06 (0.71, 1.58)
Lacrosse	23	138 122	1.67 (0.98, 2.35)	19	138 122	1.38 (0.76, 1.99)	0.83 (0.45, 1.52)
Soccer	12	373 576	0.32 (0.14, 0.50)	14	373 576	0.37 (0.18, 0.57)	1.17 (0.54, 2.52)
Sex
Males	22	437 826	0.50 (0.29, 0.71)	24	437 826	0.55 (0.33, 0.77)	1.09 (0.61, 1.95)
Females	60	474 461	1.26 (0.94, 1.58)	59	474 461	1.24 (0.93, 1.56)	0.98 (0.69, 1.41)
Season segment
Early regular seasonb	16	108 645	1.47 (0.75, 2.19)	5	108 645	0.46 (0.06, 0.86)	0.31 (0.11, 0.85)c
Middle regular seasonb	6	90 702	0.66 (0.13, 1.19)	7	90 702	0.77 (0.20, 1.34)	1.17 (0.39, 3.47)
Late regular seasonb	5	106 679	0.47 (0.06, 0.88)	10	106 679	0.94 (0.36, 1.52)	2.00 (0.68, 5.85)
Postseasonb	0	20 176	0.00	0	20 176	0.00	NA

Abbreviations: AE, athlete-exposure; CI, confidence interval; NA, not available.

^aRestricted to competition injuries for which the segment that the injury occurred was recorded.

^bSeason-by-competition interactions limited to the subset of data from 2009–2010 through 2015–2016.

^cP < .05.