Visual Analog Scales of Depression, Anxiety, and Pain as Embedded Symptom Validity Indicators in a Mixed Clinical Sample
摘要
This study was designed to examine the potential of the clinical scales of the V-5 (a visual analog scale) to serve as embedded symptom validity tests (SVTs) in a mixed clinical sample. Archival data were collected from a consecutive case sequence of 100 adult outpatients physician-referred for neuropsychological evaluation. The V-5 was administered twice: at the beginning (Time 1) and the end of the battery (Time 2). The classification accuracy of the V-5 as an SVT was calculated against psychometrically operationalized non-credible symptom report and invalid performance on cognitive testing. Using SVTs as criterion measures, ≥70 on the Depression scale had .41-.67 sensitivity at .89-.94 specificity. Different cutoffs were needed on the Anxiety scale at Time 1 (≥80; .44-.63 sensitivity at .88-.90 specificity) and Time 2 (≥65; .44-.57 sensitivity at .88-.93 specificity). A score ≥60 on the Pain scale had low sensitivity (.20-.41) but high specificity (.87-.94). Aggregating the number of failures on the V-5 within and across administrations consolidated specificity (.90-.99) at a proportional cost to sensitivity (.22-.57), correctly classifying between 84% and 93% of the overall sample. A cutoff of ≥170 on the sum of the scores on all three scales (Depression, Anxiety, and Pain; DAP) at Time 1 produced a good combination of sensitivity (.50-.75) and specificity (.92-.95), correctly classifying 87.0-93.2% of the sample. A DAP cutoff of ≥160 had comparable specificity (.91-.94), but lower sensitivity (.33-.43) and overall correct classification (83.5-89.2%) at Time 2. Results are consistent with previous research on the V-5 as an embedded SVT in student samples. Considering its low cost, the V-5 provides a practical addition to the existing list of SVTs. The fact that validity cutoffs leave little room for credible emotional distress (the invalid before clinically elevated paradox) on the V-5 introduces a psychometric conundrum that will need to be addressed in future research.