Testing the hybrid battery approach to evaluating sports-related concussion in the National Hockey League: A factor analytic study.

There has been an increased interest in the use of "Hybrid" neuropsychological test batteries to evaluate neurocognitive functioning prior to and following sports-related concussion. Typically, these test batteries include a combination of traditional "paper and pencil" (P&P) and computerized measures. The National Hockey League (NHL) employs a Hybrid approach consisting of ImPACT and a brief battery of P&P measures. The purpose of this paper was to examine the NHL's Hybrid model by means of factor analytic techniques in order to determine the extent to which the measures included in the battery are independent of each other or share common variance. Principal components analyses with promax rotations were conducted on the P&P measures alone and when combined with ImPACT. A total of 360 recently concussed NHL players underwent testing using the combined hybrid battery. A principal components analysis with promax rotation of the combined hybrid battery yielded 5 factors (Verbal Learning/Memory, Visual Learning/Memory, Processing Speed/Executive Functioning, Cued/Recognition Memory and Reaction Time/Speed). The factors appear to be relatively independent of each other with the P&P measures comprising the Verbal Learning/Memory, Visual Learning/Memory, and Processing Speed/Executive Functioning and ImPACT loading on the Cued/Recognition Memory and Reaction Time/Speed factors. These data provide support for the Hybrid model with evidence that the P&P measures and ImPACT do not measure the same domains of cognitive functioning. The clinical implications of the findings are discussed in detail.