Background: People with multiple sclerosis (MS) are less physically active than those without the disease. Understanding the modifiable factors that are related to physical inactivity is important for developing effective physical activity programs.
Objective: The objectives of this study were to determine levels of physical activity and to determine factors related to the physical activity behavior of adults with MS by use of the Physical Activity for People With a Disability (PAD) model. The PAD model combines the International Classification of Functioning, Disability and Health framework of disability and theoretical models of physical activity behavior.
Design: This investigation was a cross-sectional study.
Methods: The study participants were 106 people who had MS and who, since their definite diagnosis, had been participating in a prospective cohort study. Physical activity was assessed with the Short Questionnaire to Assess Health-Enhancing Physical Activity. The independent roles of disease characteristics and demographic, cognitive-behavioral, and environmental factors were determined using questionnaires for which reliability and validity have been established.
Results: The median total level of physical activity of participants with MS (mean age=42.8 years, median Expanded Disability Status Scale score=3, disease duration=6 years) was 10.68 metabolic equivalents x h/d (interquartile range=3.69-16.57). On average, participants spent 30 h/wk on activities with metabolic equivalents of 2 or more (interquartile range=10.7-45.0 h/wk). The regression models predicting physical activity behavior on the basis of demographic (29.4%) and disease-related (28.3%) variables explained more variance than the models based on cognitive-behavioral (12.0%) and environmental (9.1%) variables. Combining significant variables yielded a final regression model that explained 37.2% of the variance in physical activity. Significant determinants were disease severity, a disability pension, and having children to care for.
Limitations: Changes in physical activity behavior were not measured.
Conclusions: Participants with MS were less active if their disease was more severe, if they received a disability pension, or if they had children to care for. The PAD model was helpful in understanding the physical activity behavior of participants with MS.