Detection of inadequate effort on neuropsychological testing: a meta-analytic update and extension

The present meta-analysis provides the first meta-analysis of research on stand-alone neurocognitive feigning tests since publication of the preceding paper by Vickery, Berry, Inman, Harris & Orey (2001). Studies of dedicated neurocognitive feigning test performances in adults appearing in published or unpublished (theses and dissertations) sources through October 2010 were reviewed and subjected to stringent inclusion criteria to maximize the validity of results. Neurocognitive feigning tests were included only if at least three contrasts of criterion-supported honest patient groups and feigners were available. Tests that met criteria for review included the Victoria Symptom Validity Test, used as an anchor to compare Vickery and colleagues' results; Test of Memory Malingering, Word Memory Test, Letter Memory Test, and Medical Symptom Validity Test. Effect sizes and test parameters at published cut scores were compiled and compared. Results reflected large effect sizes for all measures (mean d = 1.55, 95% confidence interval [CI] = 1.48-1.63). Mean specificity was 0.90 (95% CI = 0.85-0.94). Mean sensitivity was 0.69 (95% CI = 0.63-0.75). Several moderators of effect size were identified, with certain manipulations resulting in a weakening of effect size. Unexpectedly, warning simulators to feign believably increased effect sizes.