VIP^® Test Sets New Standard in Forensic Neuropsychology

Frederick’s “homework,” as Sarfaty calls it, involves a statistical and mathematical foundation that “brings the validation of the detection of feigned cognitive impairment to a new level.” Frederick’s work, he believes, helps demonstrate that “biased responding is not a simple dichotomous distinction between valid responding and malingering.”

The VIP test uniquely includes a hierarchy of difficulty in forced-choice questions. The hierarchy of item difficulty helps quantify a respondent’s level of effort and motivation and differentiate the “realm of factors that don’t qualify as a suppressed response style, but nonetheless characterize patterns of inconsistent or irrelevant responding which are also invalid.”

The test’s performance curve analysis graphs a respondent’s performance on test items by ascending order of item difficulty. One line on the graph depicts the respondent’s expected performance assuming a compliant test-taking behavior. The second line illustrates the actual performance. For respondents with compliant response styles, the expected and actual performance lines will be similar. The two lines deviate noticeably when the response style is irrelevant, inconsistent or suppressed.

Based on his group’s experience with the VIP test, Sarfaty observes that “In fact, the irrelevant and inconsistent categories represent a larger portion of the respondents than frank malingerers.”

“Insurance companies, case management, defense council and others are eager to have objective evidence of compromises in validity so that they don’t end up paying for untrue or missed diagnoses.”

Symptom validity assessment is the standard of practice at CNS whenever there is potential for personal gain if cognitive impairment can be documented. Workers compensation, disability evaluations, medical insurance examinations, competency-to-stand-trial evaluations and child custody disputes are case examples.

Because a person may not malinger on every test in a battery or every aspect of a functional assessment, the group’s protocol is multi-modal, incorporating both test-based and non-test-based data.

“The use of the VIP test has helped us become more effective at providing diagnostic data for forensic cases—data that have raised the bar on objectively-based differential diagnosis.”

Sarfaty observes that the opportunity to be reimbursed outside of managed care and third-party payor systems helps CNS counter the prevailing pressures in the marketplace. Though the CNS protocol and subsequent analysis require “a significant chunk of time,” according to Sarfaty, “referral sources are willing to reimburse for this time because both sides in an adversarial matter can benefit significantly by objectively strengthening their findings in forensic assessments.”

“The use of the VIP test has helped us become more effective at providing diagnostic data for forensic cases—data that have raised the bar on objectively-based differential diagnosis.” These data have also helped raise the bar and increase effective consideration of the various factors than can compromise the validity of performance, the associated data, and the subsequent interpretation.”

Understanding the depth and richness of the VIP test takes some time and effort, Sarfaty observes. Malingering assessments with simple cut scores or baseline comparisons “will not prepare you to appreciate VIP results,” he says. Sarfaty suggests that clinicians study the VIP interpretive report and share questions and observations with a colleague. “This is not a major academic endeavor,” he explains, “it will only take a few such discussions, but it’s worth the effort to have access to a new diagnostic technology and dramatically improve what you have to offer.”

There are certain cases, Sarfaty notes, where VIP results are particularly applicable. Using the VIP test in these cases will clearly demonstrate the test’s uniqueness, he believes, helping clinicians more quickly understand its utility.

One type of case involves some brain compromise or psychopathology with superimposed validity compromise. “Just because you have a brain injury doesn’t mean you can’t feign impairment,” he explains. “The VIP test is particularly helpful in teasing that out.”

The VIP test can also be especially helpful in “surprisingly common cases where a person’s compromised effort and motivation is, in part, compliance with a previous misdiagnosis of brain injury.” These misdiagnosed individuals may believe their ability is compromised, so they tend to act that way. It’s not cheating or flat-out malingering, Sarfaty suggests, but “a response to feedback from perceived authorities.”

Overall, Sarfaty acknowledges that taking the time to incorporate a major new test into established protocols is not always easy. But he also recognizes that the profession is “hurting and frustrated. We are focused on getting the maximum possible advantage out of every minute and every dollar. But taking the time to understand how the VIP test works and using it your practice can more than balance out the losses to managed care.”