Predicting Premorbid Scores on the Repeatable Battery for the Assessment of Neuropsychological Status and their Validation in an Elderly Sample

Objective: Assessing cognitive change during a single visit requires the comparison of estimated premorbid abilities and current neuropsychological functioning. Although premorbid intellect has been widely examined, premorbid expectations for other cognitive abilities have received less attention. The current study sought to develop and validate premorbid estimates for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Method: Using demographic variables and an estimate of premorbid intellect, premorbid performance on the RBANS was predicted in a sample of 143 community-dwelling, cognitively intact older adults. Results: On all six Indexes of the RBANS, premorbid intellect was the best predictor of current cognitive functioning, with gender adding to one of the prediction models (R-2 = 0.04-0.16, ps < .02). These prediction formulae were then applied to a sample of 122 individuals with amnestic Mild Cognitive Impairment to look for discrepancies between premorbid and current RBANS scores. Despite minimal differences between premorbid and current RBANS scores in the intact sample, large, and statistically significant differences were observed in the impaired sample, especially on the Immediate Memory Index (discrepancy = -29.00, p < .001), Delayed Memory Index (discrepancy = -32.28, p < .001), and Total Scale score (discrepancy = -25.58, p < .001). Conclusion: Although validation in larger samples is needed, the current estimates of premorbid RBANS abilities may aid clinicians in determining change across time.