Table 1 Inter-rater reliability (κ, ICC) for naïve and expert raters for each component of the form
|  | Expert raters ( κ ) | McHugh [34] κ Agreement Classification | Naïve raters ( κ ) | McHugh [34] κ Agreement Classification |
Component | ||||
 Game time | 1.00 | Perfect | 1.00 | Perfect |
 Score | 1.00 | Perfect | 0.95 | Perfect |
 Day/night game | 1.00 | Perfect | 0.70 | Moderate |
 Tackle number | 1.00 | Perfect | 0.75 | Moderate |
 Ball carrier vs. tackler | 1.00 | Perfect | 0.92 | Perfect |
 Playing position | 1.00 | Perfect | NR | N/A |
 Tackle height | 1.00 | Perfect | 0.86 | Strong |
 Foul play | 0.90 | Perfect | 0.89 | Strong |
 Offending player on report | 0.90 | Perfect | 1.00 | Perfect |
 Type of play | 1.00 | Perfect | 0.56 | Weak |
 Initial contact | 0.90 | Perfect | 0.90 | Perfect |
 Secondary contact | 0.71 | Moderate | 0.27 | Minimal |
 Region of contact | 1.00 | Perfect | 1.00 | Perfect |
 Location of impact | 1.00 | Perfect | 0.70 | Moderate |
 Anticipation of impact | 0.70 | Perfect | 0.37 | Minimal |
 On-field medical attention | 1.00 | Perfect | 0.65 | Moderate |
 Removal from play | 1.00 | Perfect | 1.00 | Perfect |
 How did the player leave | 1.00 | Perfect | 1.00 | Perfect |
 Location of the field | 1.00 | Perfect | 0.79 | Moderate |
 Did they return to play | 1.00 | Perfect | 0.43 | Weak |
|  | Expert raters (ICC) |  | Naïve raters (ICC) (95% CIs) |  |
 Number of players in tackle | 1.00 |  | 0.87 (0.68–0.95) |  |
 Time taken to leave | 1.00 |  | 0.99 (0.97–1.00) |  |
|  | Expert raters ( κ ) (95% CIs) | McHugh [34] κ Agreement Classification | Naïve raters ( κ ) (95% CIs) | McHugh [34] κ Agreement Classification |
Concussion signs | ||||
 Clutch or shake head | 0.73 (0.46–0.93) | Moderate | 0.63 (0.36–0.87) | Moderate |
 Slow to get up | 0.83 (0.15–1.00) | Moderate | 0.52 (0.09–1.00) | Strong |
 Gait ataxia | 0.73 (0.47–0.94) | Moderate | 0.60 (0.58–0.61) | Moderate |
 Blank/vacant stare | 0.50 (0.23–0.76) | Weak | 0.44 (0.15–0.71) | Weak |
 Unresponsiveness | 0.78 (0.56–1.00) | Moderate | 0.70 (0.45–0.93) | Moderate |
 Post-impact seizure | 0.65 (N/A) | Moderate | 0.53 (0.04–0.90) | Moderate |