Advanced interpretation of the Neuropsychological Assessment Battery with older adults: base rate analyses, discrepancy scores, and interpreting change.

The purpose of this study is to provide sophisticated psychometric information for advanced interpretation of the Neuropsychological Assessment Battery (NAB) with older adults. This information includes the base rates of low scores, intellectual-cognitive discrepancy scores, and a method for determining change. The NAB contains 24 co-normed neurocognitive tests across five domains (i.e., Attention, Language, Memory, Spatial, and Executive Functions); provides 36 primary T-scores, five domain indexes, and a total index score; and was co-normed with a measure of intellectual abilities (Reynolds Intellectual Assessment Scales; Reynolds Intellectual Screening Test [RIST]). Participants for this study were 742 older adults from the NAB standardization sample (mean age = 68.1, SD = 6.9). From the standardization sample, 42 older adults (mean age = 67.3 years, SD = 8.3) were administered the NAB two times (mean retest interval = 6.7 months, SD = 0.7). The base rates of low index scores and low primary scores are presented for the entire sample, as well as stratified by the level of intellectual abilities. RIST-NAB discrepancy scores are presented for the entire sample and for the different levels of intellectual abilities. Finally, information needed to interpret change in test performance on serial assessments is provided.