| Context: Test-retest reliability is a critical issue in utilization of computerized neurocognitive assessments employing pre-participation baseline test followed by a series of post-concussion tests. Low test-retest reliability was reported by Broglio et al. (2007) for one of the most widely used neurocognitive test battery, Immediate Post Concussion Assessment and Cognitive Testing (ImPACT) with specific testing intervals.;Purpose: The purpose of this study was to re-examine the test-retest reliability of ImPACT between baseline, 45 days and 50 days after baseline.;Methods: A total of 88 physically active college students (54 male, 34 female) volunteered for this study. A repeated-measures design was used with test group (administration of ImPACT at baseline, 45days after the baseline, and 50 days after the baseline) as the independent variable and ImPACT composite scores (Verbal Memory, Motor Processing Speed, and Reaction Time) as the dependent variables. The pre-testing survey was administered to assess the participants' physical activity level and physical and mental condition on the testing day. Following the pre-testing survey, the Rey's 15-item memory test was administered before each ImPACT administration as an effort measurement. Following ImPACT, the post-testing survey was administered to assess the testing environment.;Results: Intraclass correlation coefficients between baseline to Day 45, Day 45 to Day 50, baseline to Day 50, and overall intraclass correlation coefficient were reported as follows: visual memory (.76, .69, .66, .78), verbal memory (.72, .66, .60, and .75), motor processing speed (.86, .87, .84, .90), and reaction time (.68, .83, .72, and .81). All intraclass correlation coefficient values exceeded the threshold value of .60 for acceptable test-retest reliability. The pre and post-testing survey with 0 to 10 likert scales revealed the participants were moderately stressed (average 4.64) and mildly fatigued (average 3.45), with low level of distraction (average 1.73) while completing the ImPACT test. With an exception of one participant, all participants scored perfect on Rey's 15-item Memory test.;Conclusion: Results of this study suggest that ImPACT is a reliable neurocognitive test battery over 45 and 50 days after baseline assessment. The current study's findings agree with other test-retest reliability studies that have reported acceptable intraclass correlation coefficients over different testing intervals, which support the utilization of ImPACT for the multidisciplinary approach to concussion management. |
