Annual Study Visit Data

Data Description

The Adult Changes in Thought (ACT) Study annual visit dataset contains all 4,210 annual follow-up study visits (as of the current data freeze date March 5, 2020) ever completed by the 1,347 ACT participants who had developed dementia during biennial follow-up. For convenience, the biennial visit that led to a participant’s dementia diagnosis is additionally included in this dataset. Note, though, that participants with dementia who did not complete at least one follow-up visit on this annual track (N=279) do not appear in this dataset.

This dataset includes one row per visit and contains only a limited set of variables. It is meant to serve as the core starting file to which other datasets are linked. 

Key Publications

The following publications provide additional detail on the annual study visit data elements. These may be helpful supporting citations when publishing analyses using these data. 

• Kukull WA, Higdon R, Bowen JD, McCormick WC, Teri L, Schellenberg GD, van Belle G, Jolley L, & Larson EB. (2002). Dementia and Alzheimer disease incidence: a prospective cohort study. Archives of Neurology, 59(11), 1737–1746. https://doi.org/10.1001/archneur.59.11.1737 
• Larson EB, Wang L, Bowen JD, McCormick WC, Teri L, Crane P, & Kukull W. (2006). Exercise is associated with reduced risk for incident dementia among persons 65 years of age and older. Annals of Internal Medicine, 144(2), 73–81. https://doi.org/10.7326/0003-4819-144-2-200601170-00004  

Data Dictionary

An interim data dictionary is available to provide additional information about ACT data variables.