The Development of a Reduced-Item Structured Inventory of Malingered Symptomatology (SIMS)

Abstract

Effort assessment is a relevant area in neuropsychological assessment. There are well-established self-report measures, such as the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) FBS Symptom Validity Scale (FBS; Lees-Haley, English & Glenn, Psychological Reports 68: 203-210, 1991) and MMPI-2 Response Bias Scale (RBS; Gervais, Ben-Porath, Wygant & Green, Assessment 14: 196, 2007). However, there is also a need for brief measures of symptom exaggeration. The Structured Inventory of Malingered Symptomatology (SIMS) appears to be a promising self-report measure of symptom validity (e.g., Smith & Burger, Academy of Psychiatry and the Law 25: 183-189, 1997). In order to understand the psychometric properties of the SIMS, a comprehensive item analysis was performed with the questionnaire. Items were removed due to invariable response or lack of relationship with the total SIMS. Receiver operating characteristics (ROC) curve analyses were completed using RBS and FBS Symptom Validity Scale (FBS) of the MMPI-2 with items grouping from the SIMS indices. The results found that limiting the number of items did not affect overall utility. The abbreviated indices on the SIMS had excellent discrimination with the neurologic impairment (NI) and affective disorder (AF) scales and good discrimination with psychosis (P) and amnesic disorder (AM) scales of the SIMS. The briefer measure allows for less time required to administer the measure, while still maintaining the integrity of the SIMS.