Assessment of progression and prognosis in 'possible' and 'probable' Alzheimer's disease

Abstract

Objective: The objective of this study was to assess the rate of progression and clinical predictors of decline in subjects with possible and probable Alzheimer's disease (AD).

Design/setting: The annual rate of change (ARC) for cognitive/functional scales was calculated for 95 subjects with AD attending a memory clinic. Two consecutive ARCs were calculated for a subgroup of 39 subjects.

Results: The ARCs were relatively normally distributed; however, there was a large degree of variability. Neither age nor duration of symptoms at presentations were predictive of the rate of decline. However, the data suggested an effect of gender, with males having a greater rate of decline in cognition (p = 0.02). Finally, the rate of progression over the first year did not predict the subsequent ARC (p = 0.25).

Conclusions: The high variability in ARCs observed in this study and poor correlation between consecutive ARCs suggest that neither mean ARC values nor the previous rate of decline can be used to aid clinicians in the assessment of response to acetylcholinesterase inhibitors or other specific treatments for AD.