Latent Class Analysis of Malingering Classifications Using Performance and Symptom Validity Measures in a Civil Forensic Setting

Abstract

The study examined the applicability of various validity measures and their ability to identify patterns of invalid responding (i.e., malingering) in an archival sample of civil forensic litigants. A latent clustering approach was used to create profiles comprised of the response patterns from validity measures of different domains including three performance validity tests (PVT), five symptom validity scales (SVT), and an embedded validity indicator (EVI). Latent class analysis (LCA) was used to enumerate subgroups of malingering and to assess differences between the subgroups. Results demonstrated five distinct classes. The classes revealed complex patterns of symptom endorsement and performance on validity measures that were indicative of malingering. The profiles were labeled as follows: Definite Malingering, Probable Neurocognitive Malingering, Probable Symptom Malingering, Possible Malingering, and Valid Responders. The Definite Malingering class had the highest failure rates for performance (below cut-off and below chance) and embedded validity test, as well as, the largest percentage of symptom over-endorsement and invalid responding on the symptom validity scales [i.e., F-r, Fpr, Fs, FBS-r, RBS of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF)]. The Probable Neurocognitive Malingering class had the second highest percentage of below cut-off failure (below chance performance was absent from this group) on the performance validity measures but had less evidence of invalid responding on the symptom validity scales as opposed to the Definite Malingering or Probable Symptom Malingering classes. The Probable Symptom Malingering class had a higher percentage of PVT above cutoff performance (i.e., pass), however, it had a large percentage of symptom over-endorsement and invalid responding second only to the Definite Malingering class. The Possible Malingering class demonstrated minimal evidence of failure on the three PVTs (i.e., less than 15% failed below cut-off) and there was overall less evidence of symptom over-reporting and invalid responding. The Valid Responders class had the highest level of passing on the performance validity tests and had the highest overall percentage of valid responding on the symptom validity scales. Implications of the findings and limitations are discussed.