ACT_Followup
Population
ACT population
The study population consists of 2581 men and women aged 65 or greater, in the Seattle area.
Data Collection Event
ACT - Follow-up
Every two years, cohort members were rescreened to identify new cases of dementia. Cognitive Abilities Screening Instrument scores lower than 86 at follow-up triggered a full dementia diagnostic evaluation by study physicians and a neuropsychologist. The full diagnostic evaluation included a physical and neurological examination with laboratory testing and imaging, coupled with a complete battery of neuropsychological tests.
Participants who were evaluated and did not meet criteria for dementia or Alzheimer's disease continued to be followed as participants without dementia.
Participants who met criteria for dementia or Alzheimer's disease were tested annually thereafter to observe natural history of disease, to verify clinical diagnosis, and to obtain autopsy confirmation, wherever possible.