Factors Associated with Excessive Sitting Time in Multiple Sclerosis

Background: To date, no studies have examined predictors of excessive time spent in sedentary behavior in individuals with multiple sclerosis (MS). Objectives: The objective of this study was to examine the sociodemographic, clinical, and behavioral factors associated with excessive sitting time in persons with MS. Methods: Data were obtained from 8004 persons with MS who completed the semi-annual survey of the North American Research Committee on Multiple Sclerosis registry conducted in the spring of 2015. Sociodemographic, clinical, and behavioral data were collected using self-report questionnaires. Sitting time per day was determined using the International Physical Activity Questionnaire. We conducted data analyses in May-June 2017 and defined excessive sitters as those classified above the 75^th percentile of sitting time. Multivariate binary logistic regression was used to calculate the odds ratios for being an excessive sitter for sociodemographic, clinical, and behavioral variables. Results: The results indicated that participants who were moderately disabled, severely disabled but ambulatory, or severely disabled but non-ambulatory were 1.57, 2.62, and 8.70 times more likely to be excessive sitters than those reporting mild disability. Persons with MS who were insufficiently active were 2.61 times more likely to be excessive sitters than persons who were sufficiently active. Conclusions: This study identified disability status and physical activity levels as two prominent factors associated with the likelihood of being an excessive sitter in MS and this will inform the design of future interventions for reducing sedentary behavior in this population.