Table 2 Available Psychometric properties of identified scales/checklists
Scale/checklistSampleReliabilityValiditySensitivitySpecificityChange scores
MeasureStatisticTest-retest interval
Post-concussion scale (20 item)38200 ControlCronbach α0.87NANRNRNRNR
76 ConcussedSpearman nonparametric0.55NRNRNRNRSEM = 4.17
Coefficient (r)Change = 14.8 points
Post-concussion scale (ImPACT)-22 item221746 ControlCronbach α0.88 to 0.94*NANRNRNRSEM = 2.66 change =  +3.4 points (young men)
260 ConcussedCronbach α0.93NANRNRNRSEM = 3.46 change =  ±4.4 points (young women)
SEM = 5.29 change = 6.8 points
Post-concussion scale (ImPACT)-22 item‡102635 ControlCronbach αNANAConstructNRNRNR
115 Concussed
Post-concussion scale (ImPACT)-21 item8556 ControlPearson test-retest correlation0.65 (composite scores)5.8 daysNRNASdiff  = 7.17
41 ConcussedNANAPS and <72 hrsNABetween group effect size; d = 0.9980% CI  = 9.18
Post-concussion scale (ImPACT)-21 item4766 ControlNRNRNANR81.9% (combined with ImPACT)89.4% (combined with ImPACT)NR
72 Concussed
Graded Symptom Scale-17 item456 ControlNRNRNANR0.94–0.04†1.00NR
94 Concussed
SCAT post-concussion symptom scale-25 item6NANRNRNAFace/contentNRNRNR
Head injury scale-16 item8 21279 ControlCronbach α0.84NAFactorialNRNRNR
Head injury scale-9 item8 21279 ControlCronbach α0.78NAFactorialNRNRNR
17 ConcussedNANANAConstructNANANR
16 Control
Head injury scale-16 item8 211089 ControlNANANAFactorialNRNRNR
Head injury scale-9 item8 211089 ControlNANANAFactorialNRNRNR
  • *Varies across the various samples of healthy high school and college students. †From time of injury to day-7 post-injury. ‡Pediatric population, abstract presented at 2nd international concussion in sport conference.

  • CI, confidence interval; NA, not applicable; NR, not reported; PS, preseason; Sdiff, standard error of difference; SEM, standard error of measurement.