| The Meyers Index (MI; Meyers et al., 2002) is a composite of MMPI-2 validity scales that was created to more effectively identify noncredible symptom over-report than any single validity scale alone. Meyers et al. (2013) adapted the original Meyers Index to the MMPI-2-RF, and documented that the MI and MI-r were highly correlated, with a 93.5% agreement between the two scales for pass or fail. However, actual classification statistics were not reported. The current study examined the classification accuracy of the MI-r in a known-groups neuropsychology sample (credible = 66; noncredible = 120). Noncredible patients scored significantly higher on the MI-r, and two of five MMPI-2-RF over-report scales (FBS-r and RBS). The MI-r cut-off that maintained at least 89% specificity was ≥8; sensitivity was 21.4%, which was exceeded by sensitivity of RBS (cut-off at ≥89% specificity = ≥98; 28.6% sensitivity). When the MI-r cut-off of ≥5 recommended by Meyers et al. (2013) was applied, sensitivity was 42.9%, but specificity was only 75.4%. In conclusion, the combination of all five validity scales from the MMPI-2-RF in the revised Meyers Index in fact results in lowered effectiveness as compared to the RBS scale in isolation. |
