Table 4

ACL injury risk by occupation in members of the US Armed Forces, 2006–2018

Enlisted specialty*	Special operation forces	Mechanised/Armour	Artillery/Gunnery	Aviation	Engineers	Maintenance	Administration, intelligence and communication	Logistics	Maritime/Naval specialties
RR (95% CI)	1.19 (1.10 to 1.29)	1.05 (0.97 to 1.13)	1.07 (1.01 to 1.12)	0.93 (0.86 to 1.00)	1.04 (0.98 to 1.11)	0.93 (0.90 to 0.95)	0.93 (0.90 to 0.95)	1.00 (0.97 to 1.04)	0.81 (0.75 to 0.88)
Risk difference (per 1000 person-years)	1.0	0.3	0.4	−0.4	0.2	−0.4	−0.4	0.0	−1.0
AR (%)	15.8	4.6	6.3	−8.0	3.9	−8.0	−8.0	−0.2	−23.5
P value	<0.001	0.22	0.01	0.05	0.22	<0.001	<0.001	0.88	<0.001
NNH	1013	3915	2827	−2576	4635	−2564	−2571	−78292	−1002
Officer specialty†	Aviation officers	Engineering and maintenance	Administration	Operations and intelligence	Logistics	Services
RR (95% CI)	0.89 (0.83 to 0.94)	1.05 (0.99 to 1.12)	0.94 (0.87 to 1.02	1.07 (1.00 to 1.15)	1.13 (1.05 to 1.22)	0.92 (0.87 to 0.98)
Risk difference (per 1000 person-years)	−0.5	0.2	−0.3	0.3	0.6	−0.3
AR (%)	−12.9	5.0	−6.5	6.5	11.8	−8.2
P value	<0.001	0.12	0.13	0.06	<0.001	0.01
NNH	−2127	4581	−3984	3479	1808	−3187