56 Classification Accuracy of InformantReport on the Dementia Severity Rating Scale (DSRS) for Identifying Examinee-Generated Performance and Symptom Invalidity

Abstract

Objective:

Assessment of response validity is essential to neuropsychological assessment. Although informant report of examinee functioning has previously been associated with examinee-generated performance and cognitive symptom invalidity (PVT; SVT-C), empirically-derived guidelines for interpreting informantreport validity are lacking. This study sought to assess the classification accuracy of a widely used informant-report measure, the Dementia Severity Rating Scale (DSRS), for discriminating examinee-generated PVT and SVT-C.

Participants and Methods:

Data were collected from 145 examinee-informant dyads who completed neuropsychological batteries as part of a routine workup in an epilepsy monitoring unit. PVT status was determined by below-threshold performances on >2 indicators (Test of Memory Malingering, Wechsler Digit Span Age Corrected Scaled Score, Word Memory Test). SVT-C status was determined by above-threshold responses on both the Minnesota Multiphasic Personality Inventory-2-Restructured Form Response Bias Scale (MMPI-2-RF RBS) and Structured Inventory of Malingered Symptomatology Amnestic Disorders subscale (SIMS-AM). After assessing demographic and relational covariance via t-test and chi square analyses, receiver operator characteristic curves were derived to assess the classification accuracy of the DSRS for discriminating examinee PVT and SVT-C status.

Results:

DSRS total score demonstrated acceptable accuracy in classifying PVT status (AUC = .77), with cut scores of >21 and >15 yielding .93-.82 specificity and .44-.63 sensitivity. The DSRS also classified SVT-C status with acceptable accuracy (AUC = .71), with the aforementioned cut scores exhibiting .90-.78 specificity and .50-.64 sensitivity. The DSRS also classified SVT-C status using only one indicator (i.e., MMPI-2-RF RBS or SIMS-AM) with acceptable accuracy (AUC = .71-.72), with the aforementioned cut scores exhibiting .92 specificity and .37-.42 sensitivity.

Conclusions:

The DSRS can be used to classify examinee-generated PVT and SVT-C on an epilepsy monitoring unit. Results provide empirically-derived psychometric guidelines for interpreting informant-report response validity that are clinically useful and lay the groundwork for future investigations of informant-report response validity.