| Abstrakt: |
Objective: Some RCFT indices are effective Performance Validity Test (PVTs) during neuropsychological evaluations. A combination score that includes the copy score, true positive recognition, and atypical errors has proven to be especially useful (see Lu et al, 2003). However, this score was derived from administration that deviated from protocols outlined by Meyers & Meyers (1995) in that the Recognition trial was administered after the 3-minute delay instead of the 30-minute delay. The current study examined the utility of the RCFT combination score as a performance validity test (PVT) when completing the recognition trial after the 30-minute delay. Participants and Methods: This study utilized archival data from 298 Veterans who presented for a clinical neuropsychological evaluation at a southern Veterans Affairs Medical Center. The evaluation included up to nine PVTs and all trials of the RCFT (per Meyers & Meyers, 1995). Patients were considered credible if all PVT performance fell within normal limits. This resulted in 232 patients in the credible group (Mage = 52.9 years, SDage = 15.2, Medu = SDedu = 2.5, 88% male, 71.2% White, 28.3% Black/African American). Patients were considered non-credible if they failed >2 PVTs. This resulted in 66 patients in the non-credible group (Mage = 51.6, SDage = 13.79, Medu = SDedu = 2.4, 92.4% male, 56.1% White, 43.9% Black/African American). Group assignment was also clinically confirmed. Receiver operating characteristic (ROC) curve analyses were conducted to discriminate between credible and non-credible groups utilizing the established RCFT combination score. Results: RCFT combination scores distinguished groups, with credible participants scoring higher than non-credible participants (F[1, 296]=63.76, p<.001, d=1.11; M = 56.9, SD = 9.3 vs. M = 46.5, SD = 9.5, respectively). A ROC analysis indicated AUC =.800 (95% CI =.73 to.86). When specificity was set at >90%, a cut-score of <46.5 yielded sensitivity at 46.0%. The analogous cut-score from the Lu et al. (2003) study (i.e., <47) was associated with a specificity of 88.7 and sensitivity of 46.0% in the current study. Conclusions: As the Lu et al. (2003) established the combination score of the RCFT with procedures that deviated from the standardized protocol outlined by Meyers and Meyers (1995), clinicians who opted to adhere to Meyers and Meyers' full protocol may have concerns about using the combination score as a PVT. The current study established a similar cut-off score to what Lu et al., (2003) reported (i.e., <46.5 vs. <47) while following a different administration procedure of the RCFT. Also, the index was moderately sensitive in the current study (i.e., 45.5%) but less so than what Lu et al. reported when using a cut-score that had >90% specificity (i.e., 75.9% sensitivity). This suggests that the index may be robust to deviations in administration procedures. Difference in sensitivity could be related to difference between samples. As the current sample was derived from a clinical, VA setting, current findings extend the generalizability of the index. Future research would benefit exploring if any subgroups would benefit from adjusted cut-scores to reduce the risk of false positive identification. [ABSTRACT FROM AUTHOR] |
