VOL. 2 - FALL 214 New Study Confirms the Clinical Usefulness of the ImPACT Baseline ImPACT Testing Model Authors: Philip Schatz, Stacey obertshaw. Archives of Clinical Neuropsychology. doi: 1.19/arclin/acu41. Epub 214 Sep 1. Overview In this month s Archives of Clinical Neuropsychology, Schatz and obertshaw review the issue of baseline testing and provide data that highlights the advantages of the baseline testing model over the comparison to age or gender averages ( norms ). Specifically, this study demonstrates the superiority of the baseline model when working with athletes who fall outside of the average range on the baseline test.
ImPACT esearch eport Page 2 Purpose of Study Baseline neurocognitive testing has been increasingly recognized as a crucial component of the concussion evaluation process, and the importance of baseline neurocognitive testing has been widely acknowledged. However, no published studies have directly examined the value of baseline testing in comparison (which allows for a direct comparison to the individual athlete s pre-injury test results), to a non-baseline model that compares the athlete s post-injury performance to averages or norms for a specific age or gender group. This paper conducts a careful empirical analysis of the classification accuracy of the baseline and non-baseline model in a large sample of athletes. Methodology and esults This paper utilized a sample of 25 male and female athletes who had completed a baseline ImPACT test as well as a post-injury test within one week of suffering a concussion. The athletes ranged in age from 1 to 21 years and were injured competing in a variety of competitive sports. All athletes had completed a baseline test and athletes were classified as below average, average and above average based on accepted statistical criteria. To evaluate the baseline testing model, change from baseline testing and post-injury results were calculated reliable change indices (CIs) and regression-based statistics (Bz). For the non-baseline testing model, standard (z) scores were calculated. Please see the published article for a complete description of the statistical methodology. The authors concluded that the baseline model identified a higher number of concussed athletes as impaired, particularly when these athletes fell outside of the average range when they completed the baseline test. This suggests that the use of normative comparisons in concussed athletes may result in a substantial number of athletes being misclassified as being normal post-injury when their scores are indeed abnormal compared to their own pre-injury level of performance. Implications of Study Baseline testing has specific advantages over comparison to normative data that is based on group averages. First of all, it is well known that athletes vary widely with regard to their cognitive abilities. Comparison to normative data assumes that the athlete falls within the average range. Therefore, in the absence of a valid baseline test, when an athlete is injured, the health care professional interpreting the test is required to estimate the level of pre-injury functioning in order to assess whether their post-injury performance and any change from their personal normal. These estimations are most often based on traditional measures such as Grade Point Average (GPA), standardized test scores or past performance on intelligence tests. However, as neurocognitive tests such as ImPACT measure specific neurocognitive abilities affected by concussion, any comparison based solely on a pre-injury estimate is a less than optimal measure. Illustrative Case Example The following case example on pages -5 of this report presents the test results of a 16 year old male who has historically functioned in the above average range based on his GPA of.5 (on a 4. scale). Unfortunately, he was ill the day that his football team completed baseline testing but had a concussion two weeks after the season started. Therefore, a baseline test was not available for comparison to his post-injury test. As can be seen from his composite scores, his initial post-injury test fell in the low average to average range. So how would we evaluate his initial test results? Are his first post-injury results significantly poorer than his estimated baseline? On his second post-injury test, at which time he was asymptomatic, his scores are likely to better reflect his long-term level of functioning. Therefore, if we would have had access to baseline scores, the decision making process would have been considerably more straightforward. If this athlete had been released to play after his first post-injury test, he would have been returned to play too soon, based on his second post-injury results. ImPACT s Ongoing Commitment to esearch ImPACT s database of clinical research contains more than 19 peer reviewed and over 125 independent studies to date. Visit www.impacttest.com/research to read more.
ImPACT esearch eport Page Passport ID: KTPH-BST-XQXF XXXX-XXXX-XXXX Organization: ABC USSA-NDS High School Age: 16 Date of Birth: 1/1/1998 //1998 Height: 69 inches Gender: Male Weight: 195 lbs Handedness: ight Native country/region: Native language: United States Second language: Years Speaking: Years of education completed excluding kindergarten: 1 eceived speech therapy: epeated one or more years of school: Diagnosed learning disability: Attended special education classes: Problems with ADD/hyperactivity: Current sport: Primary position/event/class: Football Tight End Current level of participation: High School Years of experience at this level: 1 Number of times diagnosed with a concussion (excluding current injury): 1 Concussions that resulted in loss of consciousness: Concussions that resulted in confusion: Concussions that resulted in difficulty remembering events that occurred immediately after injury: Concussions that resulted in difficulty remembering events that occurred: Total games missed as a result of all concussions combined: Concussion history: Sep/214 Treatment for headaches by physician: History of meningitis: Treatment for migraine headaches by physician: Treatment for substance/alcohol abuse: Treatment for epilepsy/seizures: Treatment for psychiatric condition (depression, anxiety): History of brain surgery: Diagnosed with ADD/ADHD: Diagnosed with Autism: Diagnosed with Dyslexia: Strenuous exercise in the last hours: Page 1 9/1/214 1/1/214
ImPACT esearch eport Page 4 Exam Type Date Tested Last Concussion Exam Language Test Version Post-Injury 1 9/9/214 9/1/214 2.1 Post-Injury 9/1/214 9/1/214 2.1 Composite Scores Memory composite (verbal) Memory composite (visual) Visual motor speed composite eaction time composite Impulse control composite Total Symptom Score Percentile scores if available are listed in small type. 78 27% 94 84% 85 8% 1 1% 9.42 51% 42.18 64%.54 69%.51 8% 11 12 5 Cognitive Efficiency Index:.16.5 The Cognitive efficiency Index measures the interaction between accuracy (percentage correct) and speed (reaction time) in seconds on the Symbol Match test. This score was not developed to make return to play decisions but can be helpful in determining the extent to which the athlete tried to work very fast on symbol match (decreasing accuracy) or attempted to improve their accuracy by taking a more deliberate and slow approach (jeopardizing speed). The range of scores is from approximately zero to approximately.7 with a mean of.4. A higher score indicates that the athlete did well in both the speed and memory domains on the symbol match test. A low score (below.2) means that they performed poorly on both the speed and accuracy component. If this score is a negative number, the test taker performed very poorly on the reaction time component. Hours slept last night Medication 7 7.5 The information provided by this report should be viewed as only one source of information regarding an individualâ s level of [neurocognitive] functioning. Even though impact is based on demonstrated scientific principles and research, external factors such as improper test administration or improper test taking environment may result in inaccurate test results. These factors and others must be considered in making return-to-play decision. The information provided by this report is of a general nature and does not represent medical advice, a diagnosis, or prescription for treatment. Additionally, diagnostic or return to play decisions should not be based solely on the data generated by this report, but on an in-person evaluation made by a professional trained in concussion management in accordance with usual and standard medical practice. An individual suspected of suffering traumatic brain injury or concussion should immediately seek the advice of qualified and trained personnel for interpretation of test results and should be monitored closely for the emergence of symptoms. Impact is not responsible for any decisions based on information contained in the report. A test-takerâ s qualified and trained personnel has the sole responsibility for establishing diagnosis and suggesting appropriate treatment. Page 2 1/1/214 9/1/214
ImPACT esearch eport Page 5 Headache Nausea Vomiting Balance Problems Dizziness Fatigue Trouble falling asleep Sleeping more than usual Sleeping less than usual Drowsiness Sensitivity to light Sensitivity to noise Irritability Sadness Nervousness Feeling more emotional Numbness or tingling Feeling slowed down Feeling mentally foggy Difficulty concentrating Difficulty remembering Visual problems Total Symptom Score 2 5 2 1 Page 4 1/1/214 9/1/214 impacttest.com 1.877.646.7991