Social cognitive variables as correlates of physical activity in persons with multiple sclerosis: findings from a longitudinal, observational study.

There is a lack of data regarding the associations among changes in social cognitive variables and physical activity over time in persons with multiple sclerosis (MS). To that end, the current study adopted a panel design and analysis for examining hypothesized relationships among changes in social cognitive variables and physical activity over time in persons with MS, and this is necessary for designing effective behavioral interventions. On two occasions separated by an 18-month period, persons (N = 218) with relapsing-remitting MS (RRMS), who were initially recruited by telephone for a cross-sectional study, completed a battery of questionnaires that assessed social cognitive variables and physical activity. Those study materials were delivered and returned via the United State Postal Service. The 18-month changes in self-efficacy (path coefficient = .25, p < .01) and goal setting (path coefficient = .26, p < .01) had direct effects on residual change in physical activity. The change in self-efficacy further had an indirect effect on residual change in physical activity that was accounted for by change in goal setting (path coefficient = .05, p < .05). This longitudinal study suggests that self-efficacy and goal setting represent plausible targets for changing physical activity behavior in persons with RRMS.