The Validity and Reliability of the Turkish Version of Miller Forensic Assessment of Symptoms Test (M-FAST)

The aim of this study was to show the validity and reliability of the M-FAST Turkish Version.

Translation and back-translation of the M-FAST was done, then the M-FAST Turkish Version was created with linguistic equivalence. The study was performed with 97 detainees and convicts sent from penal institutions who were internalized at our hospital forensic psychiatry service. M-FAST Turkish Version was applied to evaluees and as a result of clinical interview according to DSM-IV-TR diagnostic criteria and various data explorations the evaluee was examined for malingering. To investigate the internal consistency of the scale, Cronbach's alpha and test-retest methods were used. In order to check the validity of the scale, in addition to the clinician's diagnosis, participants were requested to fill the Minnesota Multiphasic Personality Inventory (MMPI) F and K validity scales.

The mean age of participants was 31.8±9.3 (SD) years. 47 evaluees (48.5%) were diagnosed as malingering. In the internal consistency analysis, Cronbach's alpha Coefficient was found to be .93. Test-retest relationship that was applied to 22 evaluees was found to be highly significant and strong (r=.89, p<.001). M-FAST scores were significantly high at the malingering group (n=47) (z=-8.02, p<.001). ROC curve analysis suggested a score of ≥7 points as the optimal cut-off for a malingering level for the M-FAST. Kappa coefficients of malingering ± groups were found to be, M-FAST≥7 Kappa: .83; F>16 Kappa: .29; F-K>16 Kappa: .30. For diagnosis of malingering, M-FAST Scale and the MMPI inventory scales were evaluated with the Binary Logistic Regression analysis and only M-FAST scores were found to be significant in prediction of malingering.

The findings of this study support that, M-FAST Turkish Form represents the structure of the original scale and can be used as a reliable and valid instrument.