Validity testing and neuropsychology practice in the VA healthcare system: results from recent practitioner survey

Abstract

Objective: A survey of neuropsychologists in the Veterans Health Administration examined symptom/performance validity test (SPVT) practices and estimated base rates for patient response bias. Method: Invitations were emailed to 387 psychologists employed within the Veterans Affairs (VA), identified as likely practicing neuropsychologists, resulting in 172 respondents (44.4% response rate). Practice areas varied, with 72% at least partially practicing in general neuropsychology clinics and 43% conducting VA disability exams. Results: Mean estimated failure rates were 23.0% for clinical outpatient, 12.9% for inpatient, and 39.4% for disability exams. Failure rates were the highest for mTBI and PTSD referrals. Failure rates were positively correlated with the number of cases seen and frequency and number of SPVT use. Respondents disagreed regarding whether one (45%) or two (47%) failures are required to establish patient response bias, with those administering more measures employing the more stringent criterion. Frequency of the use of specific SPVTs is reported. Conclusions: Base rate estimates for SPVT failure in VA disability exams are comparable to those in other medicolegal settings. However, failure in routine clinical exams is much higher in the VA than in other settings, possibly reflecting the hybrid nature of the VA’s role in both healthcare and disability determination. Generally speaking, VA neuropsychologists use SPVTs frequently and eschew pejorative terms to describe their failure. Practitioners who require only one SPVT failure to establish response bias may overclassify patients. Those who use few or no SPVTs may fail to identify response bias. Additional clinical and theoretical implications are discussed.