Choosing to know less: A response to Booksh, Aubert, and Andrews

Booksh, Aubert, and Andrews have written to critique our recent paper (Greve & Bianchini, 2006a) examining the clinical implications of omitting the Retention Trial of the Test of Memory Malingering (TOMM; Tombaugh, 1996) when Trial 2 is passed. We appreciate being offered the opportunity to respond. In reading Booksh, Aubert, and Andrews (in press) it was difficult to discern a central theme to their critique, as the authors obliquely allude to many topics but without any sustained thinking on any one idea. Overall, they appear motivated by their opposition to using the Retention Trial of the TOMM and strongly object to what they believe was our conclusion: “Greve and Bianchini (2006) suggest the Retention Trial should always be administered.” They have misstated our position. Because of the risk of missing some clearly and independently defined malingers when only Trial 2 is administered, we concluded that “the present study suggests that so long as at least one other well validated forced-choice SVT is also administered the Retention Trial can be dropped. The Retention Trial should never be dropped if the TOMM is the only SVT given” (Greve & Bianchini, 2006a, p. 119). This concern and conclusion have been reiterated in two recent papers (Greve, Bianchini, & Doane, 2006a; Greve et al., 2006b). Given their apparent position, it is worth further clarifying the consequences of not administering the Retention Trial. Greve et al. (2006a) reported that 42% of independently diagnosed malingerers claiming brain trauma scored less than 45 on Trial 2, a false negative (FN) error rate of 58%. In contrast, the FN rate for the Retention Trial was 43%, 15% less than Trial 2. Greve et al. (2006b), like Greve & Bianchini (2006a) found that some malingerers passed Trial 2 only to fail (and thus be correctly detected by) the Retention Trial. In short, the Retention Trial provides additional, non-redundant information about the malingering status of individual patients. These data indicate that Booksh et al.’s (in press) assertion that including the Retention Trial when Trial 2 is passed “does not appear to increase its [the TOMM’s] usefulness in detecting malingering” lacks empirical support. In any case, the logic underlying the optional discontinuation rule is unsound. Passing a single malingering test provides no reliable information about the malingering status of that individual (Greve & Bianchini, 2004; Iverson, 2006; Millis & Volinsky, 2001; Slick, Sherman, & Iverson, 1999). As Iverson (2006) notes, “false-negative rates can be quite high on tests designed to detect poor effort because researchers tend to select cutoff scores designed to minimize