Prevalence of Low Scores in Children and Adolescents on the Test of Verbal Conceptualization and Fluency

Abstract

It is important to consider the prevalence of low scores when administering a battery of psychological tests. Understanding the prevalence of low scores is important for minimizing false-positive diagnoses of cognitive deficits in clinical practice. The purpose of this study was to expand the literature on base rates for use in children and adolescents. Participants were 408 healthy children and adolescents (M_age = 13.1 years, SD = 3.7) and 139 children and adolescents (M_age = 12.4 years, SD = 3.1) diagnosed with a medical, neurological, or learning condition. All participants were administered the Test of Verbal Conceptualization and Fluency (TVCF; Reynolds & Horton, 2006). The clinical sample performed significantly lower compared with the healthy control participants on three of the five TVCF scores. When all scores were considered simultaneously, 38% of healthy children obtained one or more scores below the 16th percentile and 15% had one or more scores in the 5th percentile or lower. By comparison, significantly higher proportions of children in the clinical sample had low scores below each of the five cutoffs (i.e., 63% had one or more test scores below the 16th percentile and 37% had one or more scores in the 5th percentile or lower). Our findings illustrate the importance of considering the prevalence of low TVCF scores in everyday clinical practice with children and adolescents.

Key words:

• assessment
• base rates
• executive functioning
• low scores
• misdiagnosis
• multivariate

ACKNOWLEDGEMENTS

Portions of this study were presented at the 29th annual meeting of the National Academy of Neuropsychology in New Orleans, LA.

Dr. Brooks receives funding from Psychological Assessment Resources Inc. and in-kind research support from the CNS Vital Signs test publishing company. Dr. Iverson has received past research funding and support from Psychological Assessment Resources Inc., other test publishing companies, and the pharmaceutical industry for studies relating to the reliability, validity, and accuracy of neuropsychological tests. Drs. Koushik and Mazur-Mosiewicz report no perceived or actual conflicts of interest related to this article. Dr. Horton and Dr. Reynolds are developers of the Test of Verbal Conceptualization and Fluency.

Notes

Note. SD = standard deviation. Degrees of freedom for ANOVAs (1,545).

¹The specific neurological disorder for these two participants was not identified.

Note. Values represent cumulative percentages of healthy children and adolescents from the TVCF standardization sample that obtained low scores. There are slight variations due to rounding. Analyses were based on simultaneously examining performance on the following five age-adjusted T-scores from the TVCF: Category Fluency (total correct), Letter Naming (total correct), Classification (number of items correct), Classification (preservation errors), and Trails C (total time).