Lennart Kirchhoff1, Tilman Steinert2. 1. Zentrum für Psychiatrie Südwürttemberg, Klinik für Psychiatrie und Psychotherapie I der Universität Ulm, Ravensburg-Weissenau, Deutschland. lennart.kirchhoff@uni-ulm.de. 2. Zentrum für Psychiatrie Südwürttemberg, Klinik für Psychiatrie und Psychotherapie I der Universität Ulm, Ravensburg-Weissenau, Deutschland.
Abstract
BACKGROUND: The symptom validity tests Word Memory Test (WMT) and "Strukturierter Fragebogen Simulierter Symptome" (SFSS, German version of the Structured Inventory of Malingered Symptomatology, SIMS) are used in psychiatric expert reviews in the context of social benefit proceedings to elucidate the validity of a patient's symptom presentation and to unveil possible malingering. Many of the studies on the WMT and the SFSS estimated the sensitivity and specificity of the tests by using student populations or healthy volunteers. The objective of the present study was to investigate the accuracy of the WMT and the SFSS in a clinical sample and if their combined use leads to better classification results. MATERIAL AND METHODS: The study was conducted as a randomized controlled trial (RCT) with 60 inpatients and outpatients with depressive and anxiety disorders. The patients randomly received one of two different instructions. The control group was instructed to answer honestly. The intervention group received the instruction to imagine themselves in the situation of a social benefit claimant who wants to emphasize a medical condition. RESULTS: For the WMT and its recommended cut-off of ≤82.5% the sensitivity was determined to be 80% and the specificity 93.3%. The SFSS achieved a sensitivity of 93.3% and a specificity of 70% with the recommended cut-off of >16. The combined deployment of the tests attained a sensitivity of 92.3% and a specificity of 95.2%. CONCLUSION: Only the combined deployment of the WMT and the SFSS yielded satisfactory results. Given the high probability of false positive classifications of malingering, the use of one of the tests alone cannot be recommended.
RCT Entities:
BACKGROUND: The symptom validity tests Word Memory Test (WMT) and "Strukturierter Fragebogen Simulierter Symptome" (SFSS, German version of the Structured Inventory of Malingered Symptomatology, SIMS) are used in psychiatric expert reviews in the context of social benefit proceedings to elucidate the validity of a patient's symptom presentation and to unveil possible malingering. Many of the studies on the WMT and the SFSS estimated the sensitivity and specificity of the tests by using student populations or healthy volunteers. The objective of the present study was to investigate the accuracy of the WMT and the SFSS in a clinical sample and if their combined use leads to better classification results. MATERIAL AND METHODS: The study was conducted as a randomized controlled trial (RCT) with 60 inpatients and outpatients with depressive and anxiety disorders. The patients randomly received one of two different instructions. The control group was instructed to answer honestly. The intervention group received the instruction to imagine themselves in the situation of a social benefit claimant who wants to emphasize a medical condition. RESULTS: For the WMT and its recommended cut-off of ≤82.5% the sensitivity was determined to be 80% and the specificity 93.3%. The SFSS achieved a sensitivity of 93.3% and a specificity of 70% with the recommended cut-off of >16. The combined deployment of the tests attained a sensitivity of 92.3% and a specificity of 95.2%. CONCLUSION: Only the combined deployment of the WMT and the SFSS yielded satisfactory results. Given the high probability of false positive classifications of malingering, the use of one of the tests alone cannot be recommended.
Authors: Emilio Rojo; Oscar Pino; Georgina Guilera; Juana Gómez-Benito; Scot E Purdon; Benedicto Crespo-Facorro; Manuel J Cuesta; Manuel Franco; Anabel Martínez-Arán; Nuria Segarra; Rafael Tabarés-Seisdedos; Eduard Vieta; Miguel Bernardo; Francisco Mesa; Javier Rejas Journal: Schizophr Res Date: 2009-09-09 Impact factor: 4.939