Predicting Estimates of Premorbid Memory Functioning: Validation in a Dementia Sample

Abstract

Formulae to estimate premorbid memory functioning in a sample of cognitively intact older adults have been developed. These formulae were validated in a small sample of patients with amnestic Mild Cognitive Impairment. However, further validation is clearly needed. The current study applied these formulae to a sample of 1,059 patients referred to a dementia clinic and compared the premorbid estimates of memory functioning with current memory abilities. Large and statistically significant differences were observed in the current sample, with premorbid memory scores exceeding current memory scores. Although some cautions should be observed when using these estimates clinically, growing support for these estimates of premorbid memory abilities may aid clinicians in determining change across time in older patients.

Social Cognition, Behaviour and Relationship Continuity in Dementia of the Alzheimer Type

“…Additional measures. Additionally, a pre-morbid measure of intelligence, the Wechsler Test of Adult Reading (WTAR) (The Psychological Corporation, 2001), was administered to all participants (see, Duff, Chelune & Dennett, 2011). Finally, a screen for emotional distress, the Hospital Anxiety and Depression Scale (HADS) (Zigmond & Snaith, 1983) was taken for all participants.…”

Emergence of Mild Cognitive Impairment in Late Middle-Aged Adults in the Wisconsin Registry for Alzheimer's Prevention

“…Because baseline testing from earlier in life is generally lacking, demographically-based prediction equations have been developed to estimate premorbid intellectual levels (e.g., Barona, Reynolds & Chastain, 1984; Crawford et al, 1989; Griffin et al, 2001) [34-36]. Duff and colleagues [37, 38] have demonstrated that this approach can be extended to estimate premorbid memory abilities based on demographics and a measure of premorbid intellect; they further demonstrated that people with aMCI show significantly greater discrepancies between actual performance and estimated premorbid performance than cognitively healthy peers. Adopting a similar approach, we used linear regression to develop prediction equations to estimate premorbid functioning for each of the aMCI-related factors using a combination of demographic variables (age, gender, race (non-Hispanic Caucasian vs. other) and premorbid intellect.…”

“…Adopting a similar approach, we used linear regression to develop prediction equations to estimate premorbid functioning for each of the aMCI-related factors using a combination of demographic variables [age, gender, and race (non-Hispanic Caucasian vs. other)] and premorbid intellect. Reading scores, used by Duff [35] and Duff et al [36] , have previously been shown to be reliable estimators of premorbid intellect [37,38] . Baseline Wide Range Achievement Test-III (WRAT-III) [39] raw reading scores were standardized using means and SDs from the WRAP baseline sample.…”

Discrepancy-Based Evidence for Loss of Thinking Abilities (DELTA): Development and Validation of a Novel Approach to Identifying Cognitive Changes

“…Word-reading scores came from the American National Adult Reading Test (ANART number of errors), which estimates general intelligence (i.e., IQ) and informs expected premorbid cognitive abilities (McGurn et al, 2004). Word-reading ability was chosen as a performance-based predictor of cognitive abilities to improve upon typical demographic-only adjustment methods (Crawford, Moore, & Cameron, 1992;Duff, Chelune, & Dennett, 2011;Duff, Dalley, Suhrie, & Hammers, 2018). All predictors were left in the equation regardless of statistical significance; this approach captures any variance explained by these commonly collected variables and more clearly allows for direct comparison of their relative prediction strengths across test scores.…”