Measurement Issues in Concussion Testing EVIDENCE-BASED MEDICINE

no NP tests had established evidence in key areas to support their clinical application. The authors admitted that there is a theoretical rationale for the use of NP tests in concussion management, but they did not provide reasons that the data derived from them do not support clinical use. The key criteria used to determine usefulness were components validating existing NP tests. Some of these tests were designed for other purposes, and we are forcing them to fit a sports medicine application. An NP test in sports must function as a measure that can identify immediate changes in cognitive function and then provide an indication of changing status throughout the recovery period. The overall poor performance of NP tests, including paper-and-pencil tests and some computer tests, may be influenced by more fundamental issues relating to the design of the test. Many existing NP tests have been constructed for populations other than athletes with sports-related concussion and are administered in an unintended manner (serial testing). The purpose of this report is to provide a critical review of design assumptions and related psychometric issues that may contribute to the poor performance of NP tests. It is also important to note that these measurement issues may be relevant to other methods used in the assessment of concussion, such as mental status ratings, symptom scales, and postural stability measures.