Commonality in Abnormality: "Abnormal" Neuropsychological Scores Are Common in Baseline Testing of Youth Athletes

Although research shows that abnormal scores are common in adults, fewer studies examine the frequency of abnormal scores within children. The present study assessed how specific tests, cognitive domains, and patient factors affect the likelihood of abnormally low scores among healthy youth athletes.

Youth athletes (n = 85, Mage = 11.72, SD = 2.23) completed a comprehensive neuropsychological battery (N = 23 tests) during baseline testing for a sport-related concussion clinical research program. "Abnormal" scores were defined using cutoffs at 1, 1.5, and 2 standard deviations (SDs) below the population mean. Univariate and multivariate Poisson regression models examined abnormal test scores as a function of age, sex, ethnicity, and Full-Scale Intelligence Quotient (FSIQ).

Using cutoffs of 1, 1.5, and 2 SDs, the percent of healthy participants with at least one abnormal test score was 61.2, 36.5, and 22.4%, respectively, indicating a high proportion of healthy participants with abnormal scores and low specificity for tests using these cutoffs. In univariate Poisson regression analyses, FSIQ and abnormal score were negatively correlated (p < .001), wherein lower FSIQ was associated with more abnormal scores. In multivariate regression analyses, lower performance on executive function, memory, and processing speed tests was significantly associated with an increased frequency of abnormal scores.

Abnormally low scores in healthy youth occur frequently and do not necessarily represent functional deficits. Cutoffs of 2 SDs should be considered for many tests to increase specificity and reduce the risk of false positive errors that could lead to negative clinical outcomes.