Pathways between physical activity and quality of life in adults with multiple sclerosis.

OBJECTIVE: This prospective study examined symptoms of depression, fatigue, pain, self-efficacy, and social support as possible intermediaries in the pathway between changes in physical activity and quality of life (QOL) across a 6-month period in persons with multiple sclerosis (MS). DESIGN AND MAIN OUTCOME MEASURES: Adults with a definite diagnosis of MS wore an accelerometer for 7 days and then completed a battery of questionnaires at baseline (n = 292) and 6-months follow-up (n = 276). The data were analyzed using panel analysis and covariance modeling in Mplus 3.0. RESULTS: The initial analysis indicated that change in physical activity was associated with a statistically significant and small residual change in QOL (beta = .07). The subsequent analysis indicated that change in physical activity was associated with residual changes in fatigue (gamma = -.17), pain (gamma = -.13), social support (gamma = .07), and self-efficacy (gamma = .11), and, in turn, changes in fatigue (beta = -.13), pain (beta = -.09), social support (beta = .18), and self-efficacy (beta = .10) were associated with a residual change in QOL. CONCLUSION: The observed pattern of relationships supports the possibility that physical activity is indirectly associated with improved QOL through pathways that include fatigue, pain, social support, and self-efficacy in individuals with MS.