Does the Effect of a Physical Activity Behavior Intervention Vary By Clinical Characteristics of Persons with Multiple Sclerosis?

Background: Behavioral interventions based on social-cognitive theory (SCT) and delivered through the Internet have significantly increased physical activity in persons with multiple sclerosis (MS). Nevertheless, there has been inter-individual variability in the pattern and magnitude of change. 

Objectives: This study examined the efficacy of a behavioral intervention based on SCT and delivered through the Internet for increasing physical activity, and the possibility that change in physical activity varied by the clinical characteristics of persons with MS. 

Methods: The sample included 82 persons with MS who were randomly assigned to one of two conditions, behavioral intervention (n = 41) or waitlist control (n = 41). We collected information on MS type, disability status, and current disease modifying and symptomatic medications before the study. All participants further completed the Godin Leisure Time Exercise Questionnaire (GLTEQ) and abbreviated International Physical Activity Questionnaire (IPAQ), and wore an ActiGraph accelerometer over one week for measuring minutes of moderate-to-vigorous physical activity (MVPA) both before and after the 6-month intervention period.

Results: ANCOVA indicated that participants in the behavioral intervention participated in significantly higher levels of physical activity than control participants following the 6-month period (p < .001). ANCOVA further indicated that MS type (i.e., relapsing vs. progressive MS) (p < .01) and disability status (i.e., mild vs. moderate disability) (p < .01) moderated the effect of the behavioral intervention on physical activity. 

Conclusions: The behavioral intervention was associated with improvements in physical activity, particularly for those with mild disability and relapsing-remitting MS.