Description of the Standardization Sample for ImPACT Version 4

Different procedures were used to obtain the standardization sample for ImPACT Version 4 for ages 12-59 and ages 60-80. The total standardization sample consisted of 72.369 individuals who completed baseline ImPACT testing. There were nearly the same number of males (36,854; 50.9%) and females (35,515; 49.1%) in the sample. The specific age and gender breakdown are presented in Table 4.

For the 12-59 sample, de-identified data of 71,815 subjects were selected from our test database. Subjects were selected based on age and gender and type of input device they used to complete the test (i.e., computer mouse versus trackpad), spoke English as a primary language, completed a baseline test in English, and were from the United States of America. Further, in order to ensure subjects were not experiencing post-concussion symptoms or chronic effects of neurological disorders, all subjects reported as not having sustained a concussion in the 6 months prior to testing and had no other neurological issues that would affect performance (e.g., history of epilepsy, meningitis, brain surgery or other neurological disease). In addition, all subjects had no self-reported diagnosis of Attention Deficit Hyperactivity Disorder or Learning Disorder. The stratification of the sample was implemented to assure inclusion of adequate cell sizes across gender and age. Age bands were constructed based on logical developmental inflection points (e.g., 1-year bands at younger ages, larger bands at older ages). All normative cases had a valid score on the test and did not trigger any of the built-in validity indicators. For a complete breakdown of the sample, please see Table 4.

The normative sample age 60-80 was collected from 8 different sites across the United States, including universities and private medical practices. Data collection took place between 2017 and 2020. All sites were IRB approved with oversite from Advarra IRB services. All subjects had to meet the following inclusion criteria to be eligible:

1. Age: 60-80
2. Primary English speaking or fluent in English.
3. Currently does not reside in a skilled nursing facility.
4. Currently not suffering from a concussion or being treated for a concussion.
5. No known physical, neurological, behavioral or psychological impairment that would affect their ability to perform the test.
6. Hearing or vision impairments that have not been corrected within normal limits.
7. A score of 24 or greater on the Mini-Metal State Examination (MMSE).
8. Signed IRB approved consent form.

Normative cases were collected by testers who underwent training to administer testing. Testers consisted of neuropsychologists, psychologists, physicians, graduate students and other trained healthcare professionals. All testing was completed in a supervised setting. It should be noted that all 60-80-year-old subjects were administered the test on a laptop or desktop computer with a computer mouse thus, there is no normative data for this age range on the computer trackpad as an input device. All data was uploaded onto a secure HIPAA compliant server and all data was de-identified for analysis.

Table 4. Age and Gender Breakdown for ImPACT Normative Sample#