JMIR Publications

ABSTRACT

Background:

Older adults struggle to maintain newly initiated levels of physical activity (PA) or sedentary behavior (SB) and often regress back to baseline levels over time. This is in part because health behavior theories that inform interventions rarely address how the changing contexts of daily life influence the processes regulating PA and SB, or how those processes differ across the behavior change continuum from adoption to maintenance. These are necessary considerations as PA and SB occur within and across days with optimal levels of these behaviors ideally maintained across the lifespan and are in part driven by temporal and situational cues that rapidly change over time. To date, little research has focused on motivational processes that regulate the dynamic nature of PA and SB adoption and maintenance on micro timescales (i.e., across minutes, hours, or days).

Objective:

The overarching goal of Project SMART (Studying Maintenance and Adoption in Real-Time) is to determine the motivational processes that regulate behavioral adoption versus maintenance over micro timescales, using a dual-process framework combined with Ecological Momentary Assessment (EMA) and sensor-based monitoring of behavior. This paper describes the recruitment, enrollment, data collection, and analytics protocols for Project SMART.

Methods:

In Project SMART older adults engaging in at least 30 minutes of moderate- to vigorous-intensity physical activity per week complete 3 data collection periods over 1 year, with each data collection period lasting 14 days. Across each 14-day data collection period, participants wear an Actigraph GT3X accelerometer on their non-dominant waist and an ActivPAL micro4 accelerometer on their anterior thigh to measure PA and SB, respectively. EMA questionnaires are randomly delivered via smartphone 10 times/day on select days in each wave and assess reflective (e.g., evaluating one’s efficacy, exerting self-control) and reactive processes (e.g., contextual cues) within the dual process framework. At the beginning and end of each data collection period, participants complete a computer-based questionnaire to learn more about their typical motivation for PA and SB, as well as physical and mental health and life events over the course of the study.

Results:

Recruitment and enrollment were completed in February 2022, and data collection was completed in December 2022. Data was collected on 202 older adults during the first data collection period, with approximate retention rates of 90.1% (n = 182) at the second data collection period and 88.1% (n = 178) at the third data collection period. Multilevel models and mixed-effects location scale modeling are used to evaluate the study aims.

Conclusions:

Ultimately, Project SMART seeks to predict and model the adoption and maintenance of optimal levels of PA and SB among older adults. In turn, this will inform future delivery of personalized intervention content under conditions when the content will be most effective to promote sustained behavior change among older adults.