Table 6 Intra-rater reliability and inter-rater reliability for the concussion signs
|  | Intra-rater (κ) (95% CIs) | McHugh [33] κ agreement classification | Inter-rater (κ) (95% CIs) | McHugh [33] κ agreement classification | Absolute disagreement (CIR cases, n = 162) |
|---|---|---|---|---|---|
Clutch of shake head | 1.00 (–,–) | Perfect | 0.76 (0.60–0.91) | Moderate | 43 |
Slow to get up | 1.00 (–,–) | Perfect | 0.64 (0.42–0.83) | Moderate | 27 |
Gait ataxia | 0.77 (0.63–0.90) | Moderate | 0.37 (0.21–0.53) | Minimal | 36 |
Blank/vacant stare | 0.65 (0.44–0.84) | Moderate | 0.22 (0.05–0.40) | Minimal | 71 |
Unresponsiveness | 0.84 (0.70–0.94) | Strong | 0.75 (0.56–0.92) | Moderate | 22 |
Post-impact seizure | 1.00 (–,–) | Perfect | 0.40 (0.00–0.72) | Weak | 3 |