TOMM Trial 1 as a performance validity indicator in a criminal forensic sample

To determine the effectiveness of the Test of Memory Malingering Trial 1 (TOMM1) as a freestanding Performance Validity Test (PVT) as compared to the full TOMM in a criminal forensic sample.

Participants included 119 evaluees in a Midwestern forensic hospital. Criterion groups were formed based on passing/failing scores on other freestanding PVTs. This resulted in three groups: +MND (Malingered Neurocognitive Dysfunction), who failed two or more freestanding PVTs; possible MND (pMND), who failed one freestanding PVT; and -MND, who failed no other freestanding PVTs. All three groups were compared initially, but only +MND and -MND groups were retained for final analyses. TOMM1 performance was compared to standard TOMM performance using Receiver Operating Characteristic (ROC) analyses.

TOMM1 was highly predictive of the standard TOMM decision rules (AUC = .92). Overall accuracy rate for TOMM1 predicting failure on 2 PVTs was quite robust as well (AUC = .80), and TOMM1 ≤ 39 provided acceptable diagnostic statistics (Sensitivity = .68, Specificity = .89). These results were essentially no different from the standard TOMM accuracy statistics. In addition, by adjusting for those strongly suspected of being inaccurately placed into the -MND group (e.g. false negatives), TOMM1 diagnostics slightly improved (AUC = .84) at a TOMM1 ≤ 40 (sensitivity = .71, specificity = .94).

Results support use of TOMM1 in a criminal forensic setting where accuracy, shorter evaluation times, and more efficient use of resources are often critical in informing legal decision-making.