Physical activity and quality of life in multiple sclerosis: intermediary roles of disability, fatigue, mood, pain, self-efficacy and social support.

Physical activity has been associated with a small improvement in quality of life (QOL) among those with multiple sclerosis (MS). This relationship may be indirect and operate through factors such as disability, fatigue, mood, pain, self-efficacy and social support. The present study examined variables that might account for the relationship between physical activity and QOL in a sample (N = 292) of individuals with a definite diagnosis of MS. The participants wore an accelerometer for 7 days and then completed self-report measures of physical activity, QOL, disability, fatigue, mood, pain, self-efficacy and social support. The data were analysed using covariance modelling in Mplus 3.0. The model provided an excellent fit for the data (chi(2) = 51.33, df = 18, p < 0.001, standardised root mean squared residual = 0.03, comparative fit index = 0.98). Those who were more physically active reported lower levels of disability (gamma = -0.50), depression (gamma = -0.31), fatigue (gamma = -0.46) and pain (gamma = -0.19) and higher levels of social support (gamma = 0.20), self-efficacy for managing MS (gamma = 0.41), and self-efficacy for regular physical activity (gamma = 0.49). In turn, those who reported lower levels of depression (beta = -0.37), anxiety (beta = -0.15), fatigue (beta = -0.16) and pain (beta = -0.08) and higher levels of social support (beta = 0.26) and self-efficacy for controlling MS (beta = 0.17) reported higher levels of QOL. The observed pattern of relationships supports the possibility that physical activity is indirectly associated with improved QOL in individuals with MS via depression, fatigue, pain, social support and self-efficacy for managing MS.