Meta-analysis of the MMPI-2 fake bad scale: utility in forensic practice

Some clinical researchers disagree regarding the clinical utility of the MMPI-2 Fake Bad scale (FBS ) within forensic and clinical settings. The present meta-analysis summarizes weighted effect size differences among the FBS and other commonly used validity scales (L, F, K, Fb, Fp, F-K, O-S, Ds2, Dsr2 ) in symptom overreporting and comparison groups. Forty studies that included FBS were identified through exploration of online databases, perusal of published references, and communication with primary authors. Nineteen of the 40 studies met restrictive inclusion criteria, resulting in a pooled sample size of 3664 (1615 overreporting participants and 2049 comparison participants). The largest grand effect sizes were observed for FBS (.96), followed by O-S (.88), Dsr2 (.79), F-K (.69), and the F- scale (.63). Significant within-scale variability was observed for seven validity scales, including FBS (Q = 119.11, p < .001). Several subsequent FBS moderator analyses yielded moderate to large effect sizes and were statistically significant for level of cognitive effort, type of overreporting comparison group, and condition associated with overreporting (e.g., traumatic brain injury, posttraumatic stress, chronic pain). Findings suggest that the FBS performs as well as, if not superior to, other validity scales in discriminating overreporting and comparison groups; the preponderance of the present literature supports the scale's use within forensic settings.