Echemendia et al 20017 | Collegiate athletes | 29 concussions, 20 controls | Graded symptom checklist | No significant differences in symptom reporting at 48 hours post injury |
Erlanger et al 20038 | High school & collegiate concussion programme | 47 concussions | Graded symptom checklist | Mean duration of symptoms = 6.02 (SD 4.82) days |
Guskiewicz et al. 20039 | Collegiate American football | 196 concussions | Graded symptom checklist | 88% recovered within 7 days of injury |
Iverson et al 200610 | High school & collegiate concussion programme | 30 concussions | Graded symptom checklist | Recovery of symptoms observed within 5–10 days of injury |
Macciocchi et al 199611 | Collegiate American football programme | 183 concussions | Symptom checklist | Recovery of symptoms observed within 5–10 days of injury |
McCrae et al 200312 | Collegiate American football programme | 94 concussions, 56 controls | Graded symptom checklist | 91% recovered by 7 days of injury |
Pellman et al 200413 | Professional American football programme | 787 concussions | Symptom checklist | 92% returned to practice within 7 days of injury |