Frequency of visible signs (VS) among players with diagnosed concussion in the 2013–2014 and 2014–2015 regular seasons
| Concussion with positive sign | Concussion with negative sign | No concussion with positive sign | No concussion with negative sign | Total | |
| Sign | True positive | False negative | False positive | True negative | |
| Loss of consciousness/motionless | 13 | 189 | 12 | 755 | 969 |
| Slow to get up following a hit to the head | 80 | 122 | 710 | 57 | 969 |
| Incoordination/balance problems | 35 | 167 | 77 | 690 | 969 |
| Blank or vacant look | 4 | 198 | 2 | 765 | 969 |
| Clutching of head after a hit | 16 | 186 | 105 | 662 | 969 |
| Visible facial injury in combination | 10 | 192 | 151 | 616 | 969 |
The total number of signs (969) includes concussion diagnoses without VS (861 events with VS and 108 diagnosed concussions with no observed VS).