Interpreting the meaning of multiple symptom validity test failure.

While it is recommended that judgments regarding the credibility of test performance be based on the results of more than one effort indicator, and recent efforts have been made to improve interpretation of multiple effort test failure, the field currently lacks adequate guidelines for using multiple measures of effort in concert with one another. A total of 103 patients were referred for outpatient neuropsychological evaluation, which included multiple measures of negative response bias embedded in standard test batteries. Using any pairwise failure combination to predict diagnostic classification was superior (sensitivity = 83.8%, specificity = 93.9%, overall hit rate = 90.3%) to using any one test by itself and to using any three-test failure combination. Further, the results were comparable to the results of logistical regression analyses using the embedded indicators as continuous predictors. Given its parsimony and clinical utility, the pairwise failure model is therefore a recommended criterion for identifying non-credible performance; however, there are of course other important contextual factors and influences to consider, which are also discussed.