@article{ref1,
title="A Two-Factor Theory for Concussion Assessment Using ImPACT: Memory and Speed",
journal="Archives of clinical neuropsychology",
year="2013",
author="Schatz, Philip and Maerlender, Arthur",
volume="28",
number="8",
pages="791-797",
abstract="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 &quot;Memory&quot; (Verbal and Visual) and &quot;Speed&quot; (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.<p /><p>Language: en</p>",
language="en",
issn="0887-6177",
doi="10.1093/arclin/act077",
url="http://dx.doi.org/10.1093/arclin/act077"
}