title: Longitudinal change in physical activity and its correlates in relapsing-remitting multiple sclerosis.
abstract: BACKGROUND
  Physical activity is beneficial for people with multiple sclerosis (MS), but this population is largely inactive. There is minimal information on change in physical activity and its correlates for informing the development of behavioral interventions.
  
  
  OBJECTIVE
  This study examined change in physical activity and its symptomatic, social-cognitive, and ambulatory or disability correlates over a 2.5-year period of time in people with relapsing-remitting multiple sclerosis.
  
  
  METHODS
  On 6 occasions, each separated by 6 months, people (N=269) with relapsing-remitting multiple sclerosis completed assessments of symptoms, self-efficacy, walking impairment, disability, and physical activity. The participants wore an accelerometer for 7 days. The change in study variables over 6 time points was examined with unconditional latent growth curve modeling. The association among changes in study variables over time was examined using conditional latent growth curve modeling, and the associations were expressed as standardized path coefficients (β).
  
  
  RESULTS
  There were significant linear changes in self-reported and objectively measured physical activity, self-efficacy, walking impairment, and disability over the 2.5-year period; there were no changes in fatigue, depression, and pain. The changes in self-reported and objective physical activity were associated with change in self-efficacy (β=.49 and β=.61, respectively), after controlling for other variables and confounders.
  
  
  CONCLUSIONS
  The primary limitations of the study were the generalizability of results among those with progressive multiple sclerosis and inclusion of a single variable from social-cognitive theory.
  
  
  CONCLUSIONS
  Researchers should consider designing interventions that target self-efficacy for the promotion and maintenance of physical activity in this population.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, 233 Freer Hall, Urbana, IL 61801, USA. robmotl@illinois.edu
authors.forename: Robert W
authors.initials: RW
authors.lastname: Motl
authors.forename: Edward
authors.initials: E
authors.lastname: McAuley
authors.forename: Brian M
authors.initials: BM
authors.lastname: Sandroff
mesh_terms: D000203:Activities of Daily Living; D000704:Analysis of Variance; D003863:Depression / Q000503:physiopathology; D004185:Disability Evaluation; D005221:Fatigue / Q000503:physiopathology; D005260:Female; D020233:Gait Disorders, Neurologic / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D009010:Monte Carlo Method; D009043:Motor Activity / Q000502:physiology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000503:physiopathology*; D010147:Pain Measurement; D012307:Risk Factors; D020377:Self Efficacy