Table 2

ACL-R incidence rate per 1000 athlete exposures and per 1000 athlete seasons with incidence rate ratio per sex (99% CI)

		Football	Handball	Basketball	Ice hockey	Floorball	Alpine sports	Total
ACL-R incidence rate and incidence rate ratio per sex per 1000 athlete exposure
Unadjusted IR	Female	1.33	1.48	1.24	0.08	0.89	0.99	1.05
(99% CI)		(1.10 to 1.62)	(1.14 to 1.93)	(0.93 to 1.65)	(0.02 to 0.26)	(0.73 to 1.09)	(0.62 to 1.59)	(0.93 to 1.18)
	Male (ref)	0.59	0.56	0.22	0.08	0.29	0.38	0.33
		(0.46 to 0.74)	(0.40 to 0.78)	(0.12 to 0.41)	(0.05 to 0.14)	(0.21 to 0.42)	(0.22 to 0.68)	(0.28 to 0.38)
Unadjusted IRR		2.28	2.67	5.61	0.94	3.02	2.59	3.21
(99% CI)		(1.68 to 3.10)	(1.73 to 4.10)	(2.86 to 11.00)	(0.26 to 3.36)	(2.02 to 4.52)	(1.27 to 5.29)	(2.63 to 3.91)
P value		<0.001	<0.001	<0.001	0.898	<0.001	<0.001	<0.001
Adjusted IR	Female	1.22	1.43	1.26	0.06	0.85	1.62	1.08
(99% CI)		(0.94 to 1.58)	(1.05 to 1.93)	(0.93 to 1.70)	(0.01 to 0.30)	(0.67 to 1.08)	(0.96 to 2.73)	(0.95 to 1.23)
	Male (ref)	0.63	0.58	0.22	0.09	0.32	0.53	0.32
		(0.48 to 0.82)	(0.41 to 0.83)	(0.12 to 0.41)	(0.04 to 0.20)	(0.22 to 0.46)	(0.31 to 0.89)	(0.27 to 0.38)
Adjusted IRR		1.95	2.44	5.69	0.62	2.68	3.08	3.33
(99% CI)		(1.27 to 3.02)	(1.49 to 4.01)	(2.79 to 11.60)	(0.07 to 5.20)	(1.65 to 4.33)	(1.58 to 6.03)	(2.65 to 4.19)
P value		<0.001	<0.001	<0.001	0.560	<0.001	<0.001	<0.001
ACL-R incidence rate and incidence rate ratio per sex per 1000 athlete seasons
Unadjusted IR	Female	20.19	23.22	17.50	1.68	14.02	17.05	16.30
(99% CI)		(16.65 to 24.49)	(17.89 to 30.14)	(13.25 to 23.11)	(0.52 to 5.35)	(11.47 to 17.15)	(11.49 to 25.31)	(14.67 to 18.10)
	Male (ref)	11.11	11.05	3.95	2.73	5.45	6.41	6.81
		(8.77 to 14.07)	(7.85 to 15.54)	(2.15 to 7.25)	(1.63 to 4.58)	(3.84 to 7.72)	(3.91 to 10.49)	(5.88 to 7.89)
Unadjusted IRR		1.82	2.10	4.43	0.61	2.58	2.66	2.39
(99% CI)		(1.34 to 2.47)	(1.37 to 3.23)	(2.27 to 8.66)	(0.17 to 2.18)	(1.72 to 3.85)	(1.41 to 5.01)	(2.00 to 2.86)
P value		<0.001	<0.001	<0.001	0.321	<0.001	<0.001	<0.001
Adjusted IR	Female	19.45	22.51	17.92	1.28	13.47	18.39	17.16
(99% CI)		(15.03 to 25.17)	(16.71 to 30.32)	(13.31 to 24.12)	(0.24 to 6.79)	(10.63 to 17.07)	(10.84 to 31.21)	(15.23 to 19.34)
	Male (ref)	11.39	11.22	3.84	2.94	5.59	6.26	6.58
		(8.67 to 14.97)	(7.88 to 15.95)	(2.06 to 7.15)	(1.39 to 6.21)	(3.85 to 8.14)	(3.70 to 10.60)	(5.64 to 7.67)
Adjusted IRR		1.71	2.01	4.67	0.44	2.41	2.94	2.61
(99% CI)		(1.11 to 2.63)	(1.23 to 3.27)	(2.30 to 9.48)	(0.05 to 3.72)	(1.49 to 3.89)	(1.48 to 5.84)	(2.12 to 3.21)
P value		0.001	<0.001	<0.001	0.318	<0.001	<0.001	<0.001

Statistical method: Negative binomial regression using maximum likelihood estimation, with log link function.
Covariates in adjusted regression model: age, division.
ACL-R, anterior cruciate ligament reconstruction; IR, incidence rate; IRR, incidence rate ratio.