Protocol for a Randomized Personalized Trial Series Testing Behavior Change Techniques to Increase Physical Activity in Older Adults (Preprint)

BACKGROUND Being physically active is critical to successful aging, but most older adults don’t move enough. Research has shown that even small increases in activity can have a significant impact on risk reduction and improve quality of life. Behavior Change Techniques (BCTs) associated with increases in activity have been identified, but prior studies on their effectiveness have primarily looked at their use in between-subjects trials and in aggregate. These approaches, while robust, fail to identify those BCTs most influential for a given individual. A personalized, or N-of-1, trial design can address this by assessing a person’s response to each specific intervention. OBJECTIVE This study is designed to test the feasibility, acceptability, and preliminary effectiveness of a virtually delivered personalized behavioral intervention to increase low-intensity physical activity (i.e., walking) in adults 45 to 75 years old. METHODS The study will be administered over 10 weeks with a 2-week baseline period followed by 4 BCTs delivered one at a time, each for 2 weeks. Physical activity will be continuously measured by a wearable activity tracker, and intervention components and outcome measures will be delivered and collected by email, text messages, and surveys. Participant satisfaction with the personalized trial will be measured at the intervention's RESULTS Examining the effect of each BCT in isolation will allow for the unique impact to be assessed. CONCLUSIONS Assessing the feasibility and acceptability of delivering a remote physical activity intervention for older adults is needed if implementation of successful behavior change can be attained. Finally, in using a personalized trial design, heterogeneity of individual responses for each BCT can be quantified and inform later National Institutes of Health (NIH) Stages of Intervention development trials.