Fast cognitive decline at the time of dementia diagnosis:: A major prognostic factor for survival in the community

Background/Aims: Current findings suggest the existence of a category of fast cognitive decliners with a poorer prognosis but better treatment response. Our study aimed at confirming the concept of fast decliners at the time of Alzheimer's disease ( AD) diagnosis which best predicts mortality, in an unselected sample. Methods: 245 incident cases of AD were selected from the French longitudinal cohort PAQUID. We investigated a different threshold of cognitive decline [ measured by the annual loss of points in the Mini Mental State Examination (MMSE) score] to define when a subject could be considered as a fast decliner. We used Cox proportional hazards models to study the relation between cognitive decline and mortality. Results: The significant threshold of decline associated with a higher mortality rate was a loss of 3 points per year in the MMSE score. Among the 245 AD cases, 83 (33.9%) subjects were considered as fast decliners. Of them, 78.3% died during the follow-up compared with 63.0% of the slow decliners (RR = 1.7, 95% CI 1.2-2.5). Conclusion: These results constitute an empirical validation of the concept of fast decliners in community-based AD patients and justify the cutoff of 3 points for the definition of this condition. Copyright (c) 2007 S. Karger AG, Basel.