Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) (contd.)
Normative Data for University Students
Within this college sample, there were no differences on the four composites that were attributable to year. There was a gender effect for the Verbal Memory Composite, but not for Visual Memory, Reaction Time, or Processing Speed. The final normative tables are based on 410 university men, and 97 university women. Normative data are based on the natural distributions of scores within these two samples.
The distributions of scores within these groups were examined and exact percentile ranks corresponding to the natural distribution of scores were assigned. Thus, these could be considered uniform percentile ranks. The distributions were not force-normalized, nor were raw scores converted to standard scores.
Table 12. Approximate Classification Ranges for Index Scores - University Men (N = 410).
| Verbal Memory | Visual Memory | Processing Speed | Reaction Time | |
| Impaired | < 71 | < 51 | < 23.8 | > .75 |
| Borderline | 72 - 77 | 52 - 60 | 23.9 - 28.3 | .74 - .67 |
| Low Average | 78 - 82 | 61 - 68 | 28.4 - 32.4 | .66 - .61 |
| Average | 83 - 94 | 69 - 94 | 32.5 - 42.0 | .60 - .52 |
| High Average | 95 - 97 | 95 - 97 | 42.1 - 46 | .0 .51 - .48 |
| Superior | 98 - 99 | 98 - 99 | 46.1 - 50.0 | .47 - .45 |
| Very Superior | 100 | 100 | > 50.1 | < .44 |
Sometimes it is useful to know if an athlete performs particularly poorly on a specific subtest. Cutoff scores for the 10th percentile and the 2nd percentiles for 11 scores derived from the 6 subtests are provided in Table 13. This table allows you to identify unusually and abnormally low subtest scores.
Table 13. Cutoff Scores for Specific Subtests
Subtests Score |
Unusually Low (< 10th Percentile) |
Impaired (< 2nd Percentile) |
| Word Memory - Learning Percent Correct | < 88% | < 83% |
| Word Memory - Delayed Memory Percent Correct | < 75% | < 63% |
| Design Memory - Learning Percent Correct | < 61% | < 50% |
| Design Memory - Delayed Memory Percent Correct | < 57% | < 45% |
| X's and O's - Total Correct (Memory) | < 5 | < 3 |
| X's and O's - Avg. Correct RT (Interference) | > .48 | > .59 |
| Symbol Match - Total Correct (Symbols) | --- | < 25 |
| Symbol Match - Avg. Correct RT (Symbols) | > 1.78 | > 2.19 |
| Color Match - Avg. Correct RT | > .95 | > 1.12 |
| Three Letters - Percent of Total Letters Correct | < 80% | < 67% |
| Three Letters - Avg. Counted Correctly | < 9.2 | < 6.6 |
Symbol match total correct is a highly skewed distribution. A 10th percentile cutoff is not available.
Normative Table 14: Men, University, N = 410
Table 15. Approximate Classification Ranges for Index Scores - University Women (N=97)
| Verbal Memory | Visual Memory | Processing Speed | Reaction Time | |
| Impaired | < 70 | < 48 | < 23.3 | > .70 |
| Borderline | 71 - 82 | 49 - 59 | 23.4 - 29.7 | .69 - .64 |
| Low Average | 83 - 86 | 60 - 69 | 29.8 - 34.3 | .63 - .60 |
| Average | 87 - 97 | 70 - 88 | 34.4 - 42.1 | .59 - .52 |
| High Average | 98 - 100 | 89 - 93 | 42.2 - 46.3 | .51 - .50 |
| Superior | --- | 94 - 96 | 46.4 - 49.2 | .49 - .48 |
| Very Superior | --- | 97 - 100 | > 49.3 | < .47 |
Cutoff scores for the 10th percentile and the 2nd percentiles for 11 scores derived from the 6 subtests are provided in Table 16. This table allows you to identify unusually and abnormally low subtest scores.
Table 16. Cutoff Scores for Specific Subtests
Subtests Score |
Unusually Low (< 10th Percentile) |
Impaired (< 2nd Percentile) |
| Word Memory - Learning Percent Correct | < 94% | < 87% |
| Word Memory - Delayed Memory Percent Correct | < 82% | < 74% |
| Design Memory - Learning Percent Correct | < 62% | < 50% |
| Design Memory - Delayed Memory Percent Correct | < 57% | < 46% |
| X's and O's - Total Correct (Memory) | < 4 | < 2 |
| X's and O's - Avg. Correct RT (Interference) | > .44 | > .49 |
| Symbol Match - Total Correct (Symbols) | --- | < 25 |
| Symbol Match - Avg. Correct RT (Symbols) | > 1.66 | > 1.94 |
| Color Match - Avg. Correct RT | > .93 | > 1.02 |
| Three Letters - Percent of Total Letters Correct | < 86% | < 73% |
| Three Letters - Avg. Counted Correctly | < 9.5 | < 7.2 |
Symbol match total correct is a highly skewed distribution. A 10th percentile cutoff is not available.
Normative Table 17: Females, University, N = 97
