Theory-based physical activity behavior change intervention in people newly diagnosed with multiple sclerosis: Study...

Physical activity (PA) is strongly recommended for people newly diagnosed with multiple sclerosis (MS). Nevertheless, this MS sub-population is physically inactive, and this disease stage might require unique interventions for promoting PA.

This proposed pilot randomized controlled trial (RCT) examines the effects of a remote-delivered, theory-based behavior change intervention for promoting PA in people newly diagnosed with MS.

The intervention was developed using a comprehensive approach guided by the Capability-Opportunity-Motivation-Behavior (COMB) Model and the Behavior Change Wheel (BCW). This two-armed RCT (NCT06355804) will enroll 50 people diagnosed with MS within the past two years. Participants will then be randomly assigned, using computer-generated random numbers with allocation concealment, into either the PA intervention or waitlist control (WLC) conditions. Participants randomized into the PA intervention condition will receive the intervention following the baseline assessment, whereas participants in WLC condition will receive the intervention after the follow-up assessment (i.e., after 16 weeks). The primary outcomes of interest include device-measured (light PA [LPA], moderate-to-vigorous PA [MVPA], step counts) and self-reported (i.e., Godin Leisure-Time Exercise Questionnaire and International Physical Activity Questionnaire) PA. Secondary outcomes include fatigue, depression, anxiety, and health-related quality of life (HRQOL). Data will be analyzed with an intent-to-treat approach, using 2 (condition) by 2 (time) mixed-effects ANOVA with effect size estimates of eta-squared (η²) and Cohen's d.

The findings will inform a full-powered RCT of the intervention for promoting immediate and sustained changes in lifestyle, PA, health outcomes, and HRQOL in people newly diagnosed with MS.