Trail-Making Test Part B: Evaluation of the Efficiency Score for Assessing Floor-Level Change in Veterans

Area of Science:

• Neuropsychology
• Cognitive Assessment
• Executive Function

Background:

• The Trail Making Test - Part B (TMT-B) is a standard measure of executive control.
• A known floor effect limits TMT-B's ability to differentiate impairment in individuals who cannot complete the task within the time limit.
• The TMT-B Efficiency Score (TMT-Be) was developed to address this limitation by assessing performance variability.

Purpose of the Study:

• To evaluate the TMT-B Efficiency Score (TMT-Be) in a longitudinal clinical sample.
• To compare the TMT-Be with the TMT-B Prorated Score (TMT-Bpr) for assessing performance variability.

Main Methods:

• A record review of 30 veterans who underwent two neuropsychological evaluations was conducted.
• Participants were unable to complete the TMT-B during at least one evaluation.
• The TMT-Be and TMT-Bpr scoring systems were used to analyze performance variability.

Main Results:

• TMT-Be demonstrated a less skewed and more platykurtic distribution compared to TMT-Bpr.
• Both TMT-Be and TMT-Bpr correlated with psychomotor speed and another executive task, showing convergent validity.
• TMT-Be, unlike TMT-Bpr, detected significant longitudinal performance decline, with age and education predicting TMT-Be difference scores.

Conclusions:

• Both TMT-Be and TMT-Bpr captured performance variability and provided variance for examining floor-level TMT-B performance.
• TMT-Be was less prone to outliers and more sensitive to detecting change over time.
• The findings support the utility of TMT-Be in research and clinical settings for assessing executive function.