B - 143 A Comparison of Structured Inventory of Malingered Symptomology (SIMS) Performance to Multiple Validity Measures in a Criminal Forensic Sample

Abstract Objective We compared valid or invalid SIMS performance to other performance and symptom validity measures. Methods Data from 119 forensic neuropsychological evaluations [competency (n = 106), forensic (n = 5), insanity (n = 5), commitment review (n = 2), and danger (n = 1)] were analyzed. Three chi-squares tests compared group membership (valid/invalid) for SIMS total score, affective (AF) subscore, or low intelligence (LI) subscore to a separate valid or invalid group membership based on MMPI-2-RF (VRIN-r and TRIN-r), WAIS-IV Reliable Digit Span, and WMT (IR, DR, and CONS) validity cutoff scores (74% failed >2 measures). Results Sample was predominately male (91.6%) and Caucasian (53.8%). Mean age was 35.1 years; mean education was 11.36 years. For SIMS total, 36% failed the SIMS but passed all other validity measures [χ 2(1) = 21.668; p < 0.001; V = 0.427] for a 64% concordance rate for overall valid performance. Individuals with valid scores on the SIMS AF subscale were likely (66%) to have valid performance on all other validity measures [χ 2(1) = 12.418; p < 0.001; V = 0.323]. Individuals with valid scores on the SIMS LI subscale were essentially at chance (52%) to have performed validly overall [χ 2(1) = 9.406; p = 0.002; V = 0.0.281]. Conclusions In this forensic criminal sample, a third of individuals failed the SIMS total score and AF subscale while having credible performance otherwise. Approximately half failed the LI subscale while passing other validity measures. Results suggest that SIMS performance is not strongly related to SVT measures that focuses on response consistency or PVT performance; there is still significant classification overlap. However, high base rate of PVT/SVT failure in this sample may limit generalizability.