The Adult Changes in Thought (ACT) Study biennial visit dataset contains all baseline study visits (N=5,763), biennial in-person follow-up visits (20,826), and telephone follow-up visits (N=1,158) ever completed by ACT participants as of the current data freeze date March 5, 2020. This constitutes a total of 27,747 visits spanning 1994 through the freeze date. A cumulative total of 1,347 ACT participants developed dementia over that time period.
This dataset includes one row per visit and contains only a limited set of demographic and administrative variables along with information of study outcomes (e.g., dementia diagnosis, etc.). It is meant to serve as the core starting file to which other datasets, including the individual study forms described below, are linked.
Research staff collect ACT participant information at study visits on paper forms. Each of these study forms collect specific domains of data. Form contents have changed over the years — some individual question items have changed, while others have been discontinued or added. Entirely new forms have also been added over the years and others discontinued.
A summary list of the standard study forms collected at ACT baseline and biennial follow-up visits are provided below.
These forms have been collected on ACT participants at in-person visits over the entirety of the ACT Study (1994 to present) unless otherwise specified:
If an ACT participant was unable to undergo one of their biennial visits, then the above forms were not collected. Instead, a check-in telephone visit was offered to collect a limited set of information from the following forms:
Starting in April 2016, ACT participants were invited to complete a take-home questionnaire as part of their ACT Study visits to capture information on activities, sedentary behavior, sleep, falls, and various other elements:
The following publications provide additional detail on the biennial study visit data elements. These may be helpful supporting citations when publishing analyses using these data.
An interim data dictionary is available to provide additional information about ACT data variables.