Texas Card Sorting Test: a Brief Test of Executive Functioning with Age-Adjusted Norms and External Validation

The Texas Card Sorting Test (TCST) is a brief test of executive functioning that involves sorting cards into groups based on like dimensions. The TCST is shorter than most available executive function measures, requires minimal language demands, and excludes negative feedback. This study generated age-adjusted normative data for the TCST in a healthy aging, normal control (NC) sample, examined its sensitivity and specificity, assessed convergent validity, and compared NC performance to an Alzheimer's disease clinical syndrome (ADCS) sample.

TCST data from 164 NC [Mage = 69.60 (SD = 8.6); Meducation = 15.46 years (SD = 2.83)] and 92 ADCS participants [Mage = 77.73 (SD = 7.55); Meducation = 13.65 years (SD = 3.53)] were obtained as part of a larger neuropsychological battery at Texas Alzheimer's Research and Care Consortium (TARCC) sites from which age-adjusted normative data were derived and sensitivity, specificity, diagnostic accuracy, and validity were examined.

TCST Logical Sorts (LS), or correct card sorts, were significantly correlated with age, education, and other executive function measures. Lower but significant correlations were seen with attention and memory measures. TCST performance (LS and total errors) significantly differed between groups [F (1,249) = 142, p < .001 and F(1,248) = 26.5, p < .001]. Receiver operating characteristics analysis yielded an AUC of 0.912, sensitivity of 75%, specificity of 73%, and classification accuracy of 84% for NC versus ADCS. Optimal T score cut-offs, regression-based norms, and a T score calculator are provided.

These findings support the TCST's validity and feasibility as a brief measure of executive functioning that can accurately discriminate between normal aging and dementia. Normative data provided will enhance interpretation of this measure.