ABSTRACT
Objective: This study investigated the potential of alternative, more liberal cutoffs on Trial 2 of the Test of Memory Malingering (TOMM) to improve classification accuracy relative to the standard cutoffs (≤44). Method: The sample consisted of 152 patients (49.3% male) with psychiatric conditions (PSY) and traumatic brain injury (TBI) referred for neuropsychological assessment in a medico-legal setting (MAge = 44.4, MEducation = 11.9 years). Classification accuracy for various TOMM Trial 2 cutoffs was computed against three criterion measures.
Results: Patients with TBI failed TOMM Trial 2 cutoffs at higher rates than patients with PSY. Trial 2 ≤49 achieved acceptable combinations of sensitivity (0.38–0.67) and specificity (0.89–0.96) in all but one comparison group. Trial 2 ≤48 improved specificity (0.94–0.98) with minimal loss in sensitivity. The standard cutoff (≤44) disproportionally traded sensitivity (0.15–0.50) for specificity (0.96–1.00).Conclusions: One error on TOMM Trial 2 constitutes sufficient evidence to question the credibility of a response set. However, the confidence in classifying a score as invalid continues to increase with each additional error. Even at the most liberal conceivable cutoff (≤49), the TOMM detected only about half of the patients who failed other criterion measures. Therefore, it should never be used in isolation to determine performance validity.
Declaration of interest
The authors report no declarations of interest.