Injury incidence rate ratios per 1000 athlete-exposures (RRAE) and per 1000 min of exposure (RRME)
| Factor | Comparison | RRAE (95% CI) | RRME (95% CI) | Study |
| Sex | ||||
| Male (ref. female) | NR | 1.03 (0.58 to 1.84) | Trojanowski27 | |
| Male (ref. female) | 1.98 (1.04 to 3.77) | 1.98 (1.04 to 3.77) | Tuominen30 | |
| Male (ref. female) | 1.14 (0.84 to 1.53) | 1.21 (0.89 to 1.63) | Macan et al 32 | |
| Male (ref. female) | 1.10 (0.95 to 1.27) | 0.73 (0.63 to 0.85) | Arriaza and Leyes33 | |
| Male (ref. female) | 0.81 (0.62 to 1.04) | 0.74 (0.57 to 0.95) | Macan et al 34 | |
| Male (ref. female) | 1.52 (1.23 to 1.88) | 1.01 (0.82 to 1.25) | Arriaza et al 36 | |
| Male (ref. female) | 1.82 (1.29 to 2.57) | 1.21 (0.86 to 1.71) | Aono et al 8 | |
| Male (ref. female) | 1.91 (1.57 to 2.33) | 1.91 (1.57 to 2.33) | Minami9 | |
| Male (ref. female) | 0.87 (0.57 to 1.31) | 0.87 (0.57 to 1.31) | Pieter38 | |
| Male (ref. female) | 2.48 (1.21 to 5.07) | 1.65 (0.81 to 3.38) | Rosso et al 39 | |
| Male (ref. female) | 0.80 (0.48 to 1.34) | 0.80 (0.48 to 1.34) | Arriaza et al 42 | |
| Male (ref. female) | 0.78 (0.58 to 1.06) | 0.80 (0.59 to 1.09) | Čierna and Lystad43 | |
| Male (ref. female) | 1.61 (1.23 to 2.11) | 1.42 (1.09 to 1.86) | Čierna et al 44 | |
| Age | ||||
| Senior (ref. junior), males only | NR | 0.84 (0.50 to 1.41) | Trojanowski27 | |
| Senior (ref. junior), males only | 1.19 (0.79 to 1.77) | NR | Tuominen30 | |
| Senior (ref. junior/cadet (15–21 years)) | 1.03 (0.76 to 1.41) | 0.69 (0.50 to 0.94) | Macan et al 32 | |
| Senior (ref. pupil/young cadet (10–14 years)) | 1.75 (1.15 to 2.67) | 0.58 (0.38 to 0.89) | Macan et al 32 | |
| Junior/cadet (15–21 years, ref. pupil/young cadet (10–14 years)) | 1.68 (1.06 to 2.65) | 0.84 (0.54 to 1.34) | Macan et al 32 | |
| ≥18 years (ref. <18 years) | 1.75 (1.35 to 2.27) | 0.88 (0.68 to 1.14) | Macan et al 34 | |
| Junior/cadet (12–17 years, ref. child (6–11 years)) | 2.85 (2.07 to 3.93) | 1.92 (1.39 to 2.65) | Čierna and Lystad43 | |
| Under 21 (18–20 years, ref. junior (16–17 years)) | 1.31 (1.02 to 1.67) | 0.96 (0.75 to 1.23) | Čierna et al 44 | |
| Competition format | ||||
| Team (ref. individual) | NR | 1.67 (1.12 to 2.48) | Trojanowski27 | |
| Shobo sanbon (ref. Shobo ipon) | 1.27 (0.96 to 1.68) | NR | Esenkaya7 | |
| Team (ref. individual) | 0.88 (0.74 to 1.05) | 0.89 (0.75 to 1.07) | Arriaza and Leyes36 | |
| Rule changes | ||||
| Mandatory hand protectors (ref. no hand protectors) | 1.03 (0.78 to 1.36) | 1.03 (0.78 to 1.36) | Johannsen and Noerregaard25 | |
| 1992 WKC (ref. 1990 WKC) | 0.87 (0.74 to 1.02) | 0.87 (0.74 to 1.02) | Esenkaya7 | |
| Post-2000 rule change (ref. pre-2000 rule change) | 0.98 (0.86 to 1.12) | 0.99 (0.86 to 1.13) | Arriaza and Leyes 33 | |
| Post-2000 rule change (ref. pre-2000 rule change) | 0.68 (0.56 to 0.81) | 0.96 (0.80 to 1.15) | Macan et al 34 | |
| Post-2015 rule change (ref. pre-2015 rule change) | 0.48 (0.34 to 0.67) | 0.43 (0.30 to 0.59) | Čierna et al 44 |
NR, not reported; WKC, world karate championship.