Rule-Out and Rule-In scales for the M test for malingering: a cross-validation.

Previous research found the M test to have limited utility for the screening of malingering. Subsequently, Rogers et al. attempted to improve the test's discriminative ability by developing an alternative scoring procedure-Rule-In and Rule-Out scales. These scales showed promising results as a brief screener for malingering with hit rates as high as 95 percent. The present study cross-validated their proposed decision rules, but found lower rates of classification accuracy. The most conservative decision rule (i.e., to maximize detection of malingerers) only identified 72.7 percent of the malingerers with a false positive rate of 50.8 percent.