Cognitive impairment or inadequate norms? A study of healthy, rural, older adults with limited education

This study established preliminary norms for nine commonly administered neuropsychological tests for a biracial sample (N = 133; White = 64, African American = 69) of nondemented, rural community-dwelling elders (mean age = 76.48; SD = 7.87) with 10 or fewer years of formal education (mean education = 6.65 years; SD = 2.14). Hierarchical multiple regression analyses revealed that education was an important predictor of performance on the Mini-Mental State Examination (MMSE), Mattis Dementia Rating Scale (MDRS), Clock Drawing, Ravens' Colored Progressive Matrices, Wechsler Adult Intelligence Scale-Revised (WAIS-R) Vocabulary and Block Design, Verbal Fluency (Category) and Logical Memory and Visual Reproduction subtests from the Wechsler Memory Scale-Revised (WMS-R), but did not predict scores on the Fuld Object Memory Evaluation or memory savings scores from the WMS-R. Race was a predictor only for WAIS-R Vocabulary and Block Design, and WMS-R Logical Memory Delayed. Approximately half of the subjects scored below the published cut-offs for the MMSE and MDRS and would have been considered mildly to moderately impaired on many of the test measures.