Date of Award

8-15-2013

Document Type

Dissertation

Degree Name

Doctor of Psychology (PsyD)

Department

Psychology

First Advisor

David J. LaPorte, Ph.D.

Second Advisor

Susan Zimny, Ph.D.

Third Advisor

Beverly Goodwin, Ph.D.

Abstract

The present study had three major objectives: (1) to evaluate the similarity of flexible assessment batteries used to evaluate dementia, (2) to investigate a possible age-bias in neuropsychological diagnosis, and (3) to gain insight into the perceived necessity of common clinical information. These objectives were accomplished using a survey mechanism to conduct the experiment. The online survey was completed by 125 INS members who are clinical psychologists currently offering neuropsychological assessment services. Demographic information was collected to assess the generalizability of study results. After viewing a standard referral request respondents were asked to list the tests commonly used to evaluate a client with subjective memory complaints. Then, each respondent was presented with two clinical vignettes: a reference vignette, which was invariant across respondents, and a test vignette that varied by age (young or old) and test performance (average, borderline, impaired). For each vignette, respondents made two diagnostic ratings (for the presence any impairment and dementia) and associated confidence ratings. Finally, respondents rated the necessity of clinical information. The primary analyses involved a between-subjects, factorial multivariate analysis of variance (MANOVA) to investigate the effects of age and test performance on diagnostic and confidence ratings. Follow-up univariate ANOVA analyses were also conducted as were post-hoc pairwise comparisons. This project resulted in several important findings. The first section of this expanded on previous literature through exploration of the process of battery selection. The results of this project indicate that neuropsychologists differ in the specific tests selected for inclusion in an dementia evaluation battery, but tend to assess similar cognitive domains. Another important finding in this study was the presence of an age bias in neuropsychological diagnosis as demonstrated by the differential accuracy of the diagnostic ratings. Finally, the results of this study suggest that a lower threshold is used for some clinical decisions, such as the diagnosis of neurological impairment. Typically, neuropsychological diagnosis relies on a standard impairment classification of two standard deviations below expected performance. However, this study found a tendency to diagnosis neurological impairment and/or dementia at lower threshold (1-1.5 standard deviations below expected performance), especially in older individuals.

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