Differences in rate of functional decline across three dementia types

Alzheimers Dement. 2013 Oct;9(5 Suppl):S63-71. doi: 10.1016/j.jalz.2012.10.010. Epub 2013 May 2.

Abstract

Background: The purpose of this study was to estimate differences in rates of functional decline in Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and vascular dementia (VaD) and whether differences vary by age or sex.

Methods: Data came from 32 U.S. Alzheimer's Disease Centers. The cohort of participants (n = 5848) were ≥60 years of age and had clinical dementia with a primary etiologic diagnosis of probable AD, DLB, or probable VaD; a Clinical Dementia Rating-Sum of Boxes score <16; and a duration of symptoms ≤10 years. Dementia diagnoses were assigned using standard criteria. Annual mean rate of change of the Functional Activities Questionnaire (FAQ) score was modeled using multiple linear regression with generalized estimating equations adjusted for demographics, comorbidities, years since onset, and cognitive status (mean follow-up = 2.0 years).

Results: FAQ declined more slowly over time in those with VaD compared with AD (difference in mean annual rate of change: -0.91; 95% confidence interval [CI]: -1.68, -0.14). VaD participants also declined at a slower rate than DLB participants, but this difference was not statistically significant (-0.61; 95% CI: -1.45, 0.24). There was no significant difference between DLB and AD. Within each group, rate of decline was more rapid for the youngest participants.

Conclusions: In this sample, findings suggested that VaD patients declined in their functional abilities at a slower rate compared with AD patients and that there were no significant differences in rate of functional decline between patients with DLB compared with those with either AD or VaD. These results may provide guidance to clinicians about average expected rates of functional decline in three common dementia types.

Keywords: Alzheimer's disease; Dementia with Lewy bodies; Disease progression; Functional decline; Instrumental activities of daily living; Vascular dementia.

MeSH terms

  • Activities of Daily Living
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / complications
  • Alzheimer Disease / psychology
  • Cognition Disorders / etiology*
  • Cohort Studies
  • Dementia* / classification
  • Dementia* / complications
  • Dementia* / psychology
  • Dementia, Vascular / complications
  • Dementia, Vascular / psychology
  • Disease Progression
  • Humans
  • Lewy Body Disease / complications
  • Lewy Body Disease / psychology
  • Middle Aged
  • Neuropsychological Tests
  • Sex Factors
  • Surveys and Questionnaires
  • United States