A two-factor theory for concussion assessment using impact: Memory and speed

Philip Schatz, Arthur Maerlender

Research output: Contribution to journalArticlepeer-review

43 Scopus citations


We present the initial validation of a two-factor structure of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) using ImPACT composite scores and document the reliability and validity of this factor structure. Factor analyses were conducted for baseline (N = 21,537) and post-concussion (N =560) data, yielding "Memory" (Verbal and Visual) and "Speed" (Visual Motor Speed and Reaction Time) Factors; inclusion of Total Symptom Scores resulted in a third discrete factor. Speed and Memory z-scores were calculated, and test-retest reliability (using intra-class correlation coefficients) at 1 month (0.88/0.81), 1 year (0.85/0.75), and 2 years (0.76/0.74) were higher than published data using Composite scores. Speed and Memory scores yielded 89% sensitivity and 70% specificity, which was higher than composites (80%/ 62%) and comparable with subscales (91%/69%). This emergent two-factor structure has improved test-retest reliability with no loss of sensitivity/ specificity and may improve understanding and interpretability of ImPACT test results.

Original languageEnglish (US)
Pages (from-to)791-797
Number of pages7
JournalArchives of Clinical Neuropsychology
Issue number8
StatePublished - Dec 2013
Externally publishedYes


  • Concussion
  • ImPACT
  • Neurocognitive testing
  • Reliability
  • Validity

ASJC Scopus subject areas

  • Neuropsychology and Physiological Psychology
  • Clinical Psychology
  • Psychiatry and Mental health


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