P1‐387: Incidence of Dementia Subtypes in a Community‐Based Prospective Cohort Study: The Adult Changes in Thought (ACT) Study
Year: 2016
Type: article
Study design: Observational Study
Abstract: Recent proposed guidelines for Alzheimer’s disease (AD) stress the importance of AD subtypes (DuBois et al., Lancet Neurology 2014). There are limited data available regarding incidence rates of AD- and non-AD dementia subtypes. ACT enrolled an initial cohort of 2,581 people aged ≥65 in 1994-1996. The Cognitive Abilities Screening Instrument (CASI) was administered. Those with CASI >85 were enrolled; those with CASI ≤85 were evaluated with clinical and neuropsychological examinations, whose results were considered at a consensus conference to complete DSM-IV and NINCDS-ADRDA criteria. Participants were followed every two years with the same procedures to identify incident dementia cases. An expansion cohort of 811 was added in 2000-2003 and continuous enrollment began in 2005. We used confirmatory factor analysis to generate composite scores for memory, executive functioning, language, visuospatial ability, and attention from the battery of cognitive tests administered at the dementia evaluation. For people with probable or possible AD, we determined individual mean scores across all domains, and identified specific impairments as >1 SD below each individual’s mean domain score. For people without clinical AD dementia, we categorized dementia etiology as indicated on DSM-IV forms from consensus conferences. The ACT study enrolled 5,200 people as of May 1, 2015, of whom ____ had at least 1 follow-up visit. Over ____ person-years of follow-up, there were 1,076 incident cases of dementia, of which 867 (81%) were incident cases of probable or possible AD. Of these, 745 (86%) had complete data with non-missing scores for all cognitive domains. Of these, 517 (69%) had a typical cognitive profile, while 228 (31%) had an atypical cognitive profile (see Table 1). These proportions were essentially identical for those with probable and those with possible AD. There were 209 people with non-AD dementias. Of these, 94 (45%) had vascular dementia; other dementia etiologies are shown in Table 2. Clinical AD with a typical pattern of cognitive deficits is the most common form of incident dementia in the community. Clinical AD with an atypical pattern of cognitive deficits is more common than non-AD dementia.
Source: Alzheimer s & Dementia
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2531982012