Adult Changes in Thought Study

Baseline and Biennial Study Visit Data

Study Visit Data.png Data Description

The Adult Changes in Thought (ACT) Study maintains a participants dataset (Subjects) containing select tracking information, and a study visits dataset (Biennial_Visits) which contains all baseline and biennial ACT study visits included in the current data freeze. This latter dataset includes one row per visit and contains only a limited set of administrative study variables (e.g., coded study ID, info regarding the visit, cohort information, etc.). It serves as the core file to which other study forms datasets are linked.

Study Forms

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 select list of standard study forms are provided below, but please see the data dictionary link at the bottom of this page for a more complete listing with detail on curated form datasets and notes regarding changes over time.

Baseline and Biennial Visits

These forms have been collected on ACT participants at in-person visits over the entirety of the ACT Study (1994 to present):

  • Form 71 – Administrative 
  • Form 72 – Vision, Hearing, and Olfaction 
  • Form 73 – Memory and Functioning
  • Form CES-D – Center for Epidemiology Studies Depression Scale
  • Form 75 – Demographics 
  • Form 77 – Medical History 
  • Form 78 – Epidemiology 
  • Form 84 – Cognitive Abilities Screening Instrument (CASI)
  • Form 85 – Blood Pressure and Neurology 

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:

  • Form 68 – Telephone Follow-up 
  • Form 69 – Telephone versions of the CASI and Adult Lifestyles and Function Interview Mini-Mental State Examination (ALFI-MMSE)

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:

  • Form 66 – Take Home Questionnaire 
    • Started offering in April 2016 and collection is ongoing 

Key Publications

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. 

  • 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  
  • Li G, Larson EB, Shofer JB, Crane PK, Gibbons LE, McCormick W, Bowen JD, Thompson ML. Cognitive Trajectory Changes Over 20 Years Before Dementia Diagnosis: A Large Cohort Study. J Am Geriatr Soc. 2017 Dec;65(12):2627-2633. doi: 10.1111/jgs.15077. Epub 2017 Sep 21. PMID: 28940184; PMCID: PMC5729097.

Data Dictionary

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