Relationship between denial of memory deficit and dementia severity in Alzheimer disease.

OBJECTIVE: To assess the relationship between denial of memory deficit and dementia severity in patients with Alzheimer disease (AD). Additionally, to introduce a new instrument, the Awareness of Memory Impairment Scale (AMIS), devised to minimize biases present in previous studies, especially those attributable to the use of difference scores and clinical ratings.
BACKGROUND: Estimates of the magnitude of denial in patients with AD, and of its relationship with disease progression, have varied across studies. Part of this variability may have resulted from differences in the way investigators measured denial. In this study, the AMIS was used to obtain a relatively unbiased assessment of the relationship between denial and disease severity in patients with AD.
METHOD: Two hundred three patients with AD were studied, 106 longitudinally, and 40 age-matched control subjects were evaluated. Multiple regression analysis, controlled for age, sex, education, and duration of illness, was used to compare AMIS scores with disease severity cross-sectionally and to determine whether AMIS scores change over time. A similar analysis was performed using difference scores and clinical ratings to determine whether introduction of a new assessment instrument was warranted.
RESULTS: Cross-sectionally, a small but statistically significant correlation between AD denial and dementia severity was found. Upon direct longitudinal assessment, no change in denial was noted after a mean interval of 1 year and 3 months. As expected, use of difference scores and clinical ratings yielded inflated correlations relative to those obtained with the AMIS.
CONCLUSIONS: Denial of memory deficit correlates minimally with dementia severity in cross-sectional analysis but is independent of disease progression when assessed longitudinally.