Psychometric Performance of the Miller Forensic Assessment of Symptoms Test (M-FAST) in Veteran PTSD Assessment

Validation of the personality assessment inventory (PAI) cognitive bias (CBS) and cognitive bias scale of scales (CB-SOS) in a post-deployment veteran sample

Objective: The present study evaluated the function of four cognitive, symptom validity scales on the Personality Assessment Inventory (PAI), the Cognitive Bias Scale (CBS) and the Cognitive Bias Scale of Scales (CB-SOS) 1, 2, and 3 in a sample of Veterans who volunteered for a study of neurocognitive functioning. Method: 371 Veterans (88.1% male, 66.1% White) completed a battery including the Miller Forensic Assessment of Symptoms Test (M-FAST), the Word Memory Test (WMT), and the PAI. Independent samples t-tests compared mean differences on cognitive bias scales between valid and invalid groups on the M-FAST and WMT. Area under the curve (AUC), sensitivity, specificity, and hit rate across various scale point-estimates were used to evaluate classification accuracy of the CBS and CB-SOS scales. Results: Group differences were significant with moderate effect sizes for all cognitive bias scales between the WMT-classified groups (d = .52-.55), and large effect sizes between the M-FAST-classified groups (d = 1.27-1.45). AUC effect sizes were moderate across the WMT-classified groups (.650-.676) and large across M-FAST-classified groups (.816-.854). When specificity was set to .90, sensitivity was higher for M-FAST and the CBS performed the best (sensitivity = .42). Conclusion: The CBS and CB-SOS scales seem to better detect symptom invalidity than performance invalidity in Veterans using cutoff scores similar to those found in prior studies with non-Veterans.