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Testing the Test; Impact Reliability Study Jean Rickerson, SportsConcussions.org Page 1 of 2

Testing the Test; Impact Reliability Study
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As state legislators, school district and sports organization officials around the country consider how to implement new concussion policies, computerized neuropsychological ("baseline") testing is often on the table. A new study suggests that while valuable, baseline testing should be used in conjunction with other measures to provide a more complete picture of the state of a concussed athlete's injury.

ImPACT (Immediate Post-Assessment and Cognitive Test), a computerized testing system commonly used to evaluate sports-related concussions misclassified up to 29 percent of healthy participants in a recent study by a kinesiology researcher at the University of Texas at Arlington.

Baseline testing

Baseline neuropsychological tests can be administered via computer, paper/pencil or through the use of a new app. Typical measurements include memory, reaction time, and information processing speed. Taken before an athlete's season begins, the test provides pre-injury cognitive performance information against which post-injury test results can be compared. Medical providers will often use these data to help determine a return-to-play schedule for the athlete.

Testing protocol

Forty-five healthy, non-athlete students between the ages of 18-24 who had not suffered a concussion within the previous six months were given a health questionnaire which included a symptom inventory. Green's Word Memory Test was then administered for five minutes before the subjects took the ImPACT test, and then again afterward. Students participated in this testing procedure on three separate occasions, first establishing a "baseline" (day 1), then 45 days later, and again five days later, at day 50.

Study results

"The results from the study of the ImPACT computerized neuropsychological testing system emphasize the need for multiple types of assessments," said Jacob Resch, an assistant professor of kinesiology and director of the University's Brain Injury Laboratory. During the study, the system had "only poor to good reliability" in 45 healthy participants, he said.

Visual motor speed was the only category out of five on the ImPACT test that met the researchers' measure of reliability. This corresponds to the X's and O's, symbol match, and "three letters" modules on the ImPACT test. Four of the five main outcome measures – composite and verbal memory, visual memory, and reaction time did not meet the criteria established by the researchers.

These findings are similar to those reported by Dr Steven Broglio (University of Michigan) in a 2007 article published in the Journal of Athletic Training. In that investigation, college students were given three common computer based tests (ImPACT, Headminder CRI, and Concussion Sentinel) at Days 1 and 45 with misclassification rates ranging from 20 to 38%. "It is good to see results that are similar to what we reported. I think when the two studies are looked at simultaneously, clinicians should be very cautious in using only one form of testing when evaluating for concussion," Broglio said.

Resch concludes the same. The error rate is less than 10% when all three testing modalities are utilized, that is, when a concussed athlete is evaluated for symptoms, balance and physical coordination, and cognitive ability.

Researchers' conclusions

"What our results stress is that when developing a sport-related concussion management protocol, a multi-facet approach including self-reported symptomology, a balance assessment and computerized neuropsychological testing should be implemented," Resch said. "Ultimately, by incorporating this approach to concussion management we are significantly reducing the risk of returning an athlete back to the playing field too soon after a concussion which may lead to catastrophic consequences."

Resch began to study the test's reliability while at the University of Georgia. Co-authors on an abstract presented at the conference include University of Georgia faculty and researchers from the Shepherd Center in Atlanta and Georgia Neurological Surgery in Athens, Ga.

"Research like this reinforces the need to look critically at what we do and make it better," said Dr. Kimberly Walpert, coauthor of the study and a partner at Georgia Neurological Surgery. "I think this is particularly important in view of the growing evidence regarding how multiple, seemingly insignificant brain injuries may have long term consequences for athletes."

Resch, who is now using ImPACT in a lab study of North Texas high school athletes at risk for concussion, said researchers wanted to add to the limited scientific examination of the ImPACT test's reliability. "When we administer the ImPACT test to the high school athletes we try to provide the optimal environment to ensure a valid baseline effort. We deliver the ImPACT individually post-injury. We test no more than 20 athletes at a time in a quiet, distraction-free computer lab in the presence of a trained clinician."

The clinician explains the test more thoroughly and describes in greater detail what the athlete will see on the screens.

Resch's findings were presented in June at the National Athletic Trainers' Association annual meeting and clinical symposia in New Orleans.

Dr. Michael Koester, Director of the Slocum Sports Concussion Program in Eugene, Oregon said, "This study highlights the difficulty in correctly diagnosing concussion, and more importantly, determining safe return to play, more so than it points out any "flaws" in ImPACT. No one uses ImPACT as a single determinant in concussion management. It is simply one tool used to help make a clinical decision."

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From SportsConcussions.org, used with permission. Written by Jean Rickerson, founder/editor. www.sportsconcussions.org.

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