Intergenerational Behavioral Intervention to Enhance Physical Activity in Older Adults at Risk for Alzheimer's Disease (HABS)

Intergenerational Behavioral Intervention to Enhance Physical Activity in Older Adults at Risk for Alzheimer's Disease

The Healthy Aging Brain Study: A Remote Behavioral Intervention to Enhance Physical Activity in Older Adults.

This is a twelve-week pilot randomized controlled trial of a behavioral intervention in older adults at risk for Alzheimer's disease. Older participants are a subgroup from the PREVENT-AD longitudinal cohort. We will test whether a four-week intergenerational social motivation using a technology-based platform (intervention group) enhances physical activity relative to a control group. After a washout period, the two groups will be offered the opportunity to cross-over into the alternate condition.

This study is a two-arm, single site cross-over randomized controlled trial to test whether a four-week technology-based intergenerational social motivation intervention enhances physical activity in 60 cognitively normal older adults with a first-degree history of Alzheimer's disease. These at-risk older adults will be recruited as a subgroup from a longitudinal cohort at McGill University, PREVENT-AD. At the outset, half of the participants will be randomized to the intergenerational social motivation condition (intervention group) and the other half will be randomized to the control group (1:1). A multimodal Alzheimer's disease (AD) risk score based on older participants' already acquired AD biomarker, health and cognitive data will be used as strata for randomization to ensure equal assignment of high-risk participants to Intervention and control groups, using a permuted block method with random blocks. The primary measure of interest is increased physical activity as measured by accelerometry (average minutes in sedentary behavior/day, average steps per day, and average minutes in moderate-to-vigorous physical activity/day). After an initial visit consisting of behavioral testing and structural and functional MRI, participants in the Intervention Group will be paired with younger adults (14 to 40 years) to form intergenerational dyads. Younger adults are either a family member of the older adult or a younger adult recruited from the community. Participants in the intervention group will receive personalized, positive daily messages over a four-week period via their device using the 'Our Family Garden' technology platform. These daily messages combine (1) pro-social goals (donation to charity after reaching exercise goals), (2) intergenerational social engagement and (3) positive personalized messages from their younger study partners. This study will have 6 visits over a 2-month period in addition to the four-week intervention period (3 months total). Cognitive and behavioral data will be collected at each visit and physical activity data will be collected over the intervention period. All participants will be offered the opportunity to cross-over, after a 6-week washout period, into the alternate condition in order to ensure access to the intervention in all participants and longer-term follow up. The primary endpoint is defined as the end of the initial period. Data collected are stored in one of three ways; (1) Physical activity monitoring data are extracted from their respective software packages and uploaded directly to a secure data storage environment at a high-performance computing facility. All pen-and-paper psychosocial and neuropsychological assessments are scored and entered in REDCap. Computerized psychosocial assessments are collected directly in REDCap and computerized neuropsychological assessments are entered in REDCap. The oTree library is used to distribute the daily intervention messages and collect survey data. This system runs on a Heroku server, a cloud-based system that sends and receives hash-encrypted links. Collected anonymized data are stored on the messaging site behind an administrative login on the Heroku server. All data from RedCAP will be exported to CSV files using the data de-identification feature for subsequent analysis with R and SPSS statistical analysis packages. After compiling all data across the 3 different data servers, data will be checked for completeness and correctness using frequency distributions (for missing data and out-of-range values). For the final dataset, the multiple imputation by chained equations (MICE) will be used for imputing missing values with 10 imputations.

Intergenerational Social Motivation Behavioral Intervention using a Technology-based Platform Our research will test an innovative, technology-based, and readily scalable cross-generational social behavior intervention to enhance physical activity in at-risk older adults within a cross-over randomized controlled trial to enhance physical activity.

Social motivation manipulation, self-transcendence daily messaging, and daily activities monitoring through accelerometry. Participants in this arm will have a study partner who receives daily feedback on the main participant's daily step count.

This metric quantifies the change in the average amount of time spent sedentary each day, from the baseline period to the 4-week period. It is a marker of time spent inactive.

This metric quantifies the change in the average number of steps taken each day, from the baseline period to the 4-week period. It is a marker of change in habitual ambulatory activity.

This metric quantifies the change in the average amount of time spent engaged in moderate-vigorous physical activity each day, from the baseline period to the 4-week followup period. It is a marker of physical activity.

This metric assessed cognitive status across multiple domains (e.g., memory, executive function, processing speed)

A questionnaire to assess physical activity confidence when faced with challenges (e.g., bad weather).

Inclusion criteria: Men and women > 60 years Part of the PREVENT-AD Longitudinal Cohort at McGill No contraindications to MRI imaging Normal cognition Not exercising more than 150 minutes of moderate-intensity exercise per week or sitting more than 8 hours per day Fluency in English or French Access to computer or smartphone with internet Exclusion criteria: Primary care physician does not approve additional physical activity An inability to ambulate without the assistance of another person or severe pain Any unstable medical condition Younger Adult Inclusion Criteria: Can be identified as child or grandchild of participant (biological or adopted), 14 years or older. Can be a young adult (18 years or older) who is not a relative of the main participant, in case a grandchild or child is not available. Stable on antidepressants for more than 6 months. In contact with the primary participant more than once per 12 months at baseline Lives anywhere accessible by mail in Canada if 18 years and older, or anywhere accessible by mail in Quebec if 14 years and older but younger than 18 years. Normal or corrected-to-normal vision based on the minimal 20/20 standard in order to complete the cognitive tasks Able to speak, read, and write English or French No diagnosis of a neurological disease or unstable health condition Regular access to a computer with internet or a smartphone Study Partner exclusion criteria • Not in contact with the primary participant more than once per 12 months at baseline