[image omitted] Derivation of a composite measure of embedded symptom validity indices

Assessment of effort on cognitive testing has become a suggested standard in both forensic and clinical neuropsychological assessment. Both stand-alone and empirically derived embedded measures have been developed, however guidelines for combining several measures are not always available. This study used logistic regression analysis to derive a multivariable composite to detect suboptimal effort using scores extracted from commonly administered neuropsychological tests. A model predicting suboptimal effort, as defined by performance on the Medical Symptom Validity Test, was created with 124 participants using variables from the California Verbal Learning test 2nd edition, Rey Complex Figure Test and the Wechsler Memory Scale 3rd edition. The model reliably predicted suboptimal effort (χ(2 )= 44.37, p < .001) with excellent discrimination (AUC = .84).