Assessment of Feigning with the Trauma Symptom Inventory: Development and Validation of new Validity Scales with Severely Traumatized Patients

Currently, only the TSI assesses complex traumatic reactions and patient response styles. However, its feigning scale, ATR, uses a flawed detection strategy and is potentially confounded by experiences of complex PTSD. As a consequence, clinicians using the TSI to evaluate severely traumatized patients have no useful method for discriminating genuine and feigned responding. Several detection strategies have demonstrated utility within evaluations of feigned trauma including the assessment of rare symptoms, symptom combinations, symptom selectivity, and symptom severity. The current study created scales on the TSI according to these strategies using a development sample of 107 severely traumatized patients. Validation of all TSI feigning scales was then performed with a second independent sample of 71 severely traumatized patients using a mixed simulation design. Results found support for each scale's convergent validity with SIRS primary scales (M rs = .52) and discriminant validity with measures of defensiveness on the SIRS (M rs = -.07) and TSI (M rs = -.19). Each scale also produced expectedly mild to moderate relationships with SADS-C clinical scales (M rs = .32) and the SCID-IV PTSD module (M rs = -.02). Support for their criterion validity was only moderate (M ds = .69) when comparing the scores of genuine patients to those simulating disability. Potential explanations for this trend were reviewed, including (a) the impact of comorbidity, (b) the restrictions associated with creating embedded feigning scales, and (c) the influence of simulator knowledge in analogue designs. Limitations of the study and future avenues of research were discussed