Multicomponent Behavior Change Technique Intervention for Caregivers of People With Alzheimer Disease and Related Dementias: Protocol for a Single-Arm, Personalized Behavioral Trial to Disrupt Sedentary Time.

Background: Sedentary behavior is associated with negative health outcomes. High levels of sedentary behavior are common among Alzheimer disease and related dementias (ADRD) caregivers already at risk of other adverse health effects, yet few interventions target sedentary behavior within this population. There is a need for trials intended to reduce time spent sedentary, which may be achievable by increasing the frequency of disruptions to sedentary time. Remotely delivered behavior change techniques (BCTs) may be effective for disrupting sedentary behavior in this population through short bursts of walking, although it is unclear how BCTs promote this behavior and potentially act via the hypothesized mechanism of behavioral automaticity. Objective: The goal of the trial is to examine whether a significant proportion of ADRD caregivers (≥50%) receiving an SMS text message-delivered BCT intervention form a habit to engage in hourly walking 4 times per day, with the broader objective of disrupting sedentary time in this population. Methods: This trial is a 12-week, decentralized, single-arm, National Institutes of Health Stage II behavioral trial. The trial will deliver a personalized, multicomponent BCT intervention to disrupt time spent sedentary by encouraging forming a habit of hourly walking among caregivers of persons with ADRD via the key mechanism of behavior change behavioral automaticity. The intervention includes 4 daily SMS text message-delivered BCT components previously used in interventions to disrupt sedentary behavior-Goal setting, Action planning, Prompts/cues, and Self-monitoring. Formation of an hourly walking habit is the primary outcome and will be defined as walking an additional 250 steps or more per hour for the same 4 consecutive hours as set up in a personalized walking plan on 7 consecutive days. Secondary outcomes include evaluating associations between habit formation and behavioral automaticity, and between longitudinal behavioral automaticity and habitual hourly walking over time. Additionally, heterogeneity of treatment effects will be evaluated. Exploratory analyses will examine potential moderating variables that may influence the intervention effect. The trial uses digital enrollment strategies, SMS text message intervention delivery, passive data collection via Fitbit (Google) devices, and online survey assessments to collect data remotely. Results: This study was funded by the National Institute on Aging in June 2024. Recruitment and data collection began in March 2025. As of August 2025, 40% (n=40) of the planned sample has been enrolled. Data collection is expected to be complete by June 2026. Data analysis and publication of results are expected by Fall and Winter 2026, respectively. Conclusions: Results will have the potential to advance knowledge about the effectiveness of BCTs to form a habit of hourly walking and may provide opportunities for future public health impact to promote physical activity in caregivers of those living with ADRD.