title: Does the effect of a physical activity behavioral intervention vary by characteristics of people with multiple sclerosis?
abstract: BACKGROUND
  Behavioral interventions have significantly increased physical activity in people with multiple sclerosis (MS). Nevertheless, there has been interindividual variability in the pattern and magnitude of change. This study documented the efficacy and variability of a behavioral intervention for changing physical activity and examined the possibility that efficacy varied by the characteristics of individuals with MS.
  
  
  METHODS
  Eighty-two people with MS were randomly assigned to one of two conditions: behavioral intervention (n = 41) or waitlist control (n = 41). We collected information before the study on MS type, disability status, weight status based on body-mass index, and current medications. Furthermore, all participants completed the Godin Leisure Time Exercise Questionnaire and the abbreviated International Physical Activity Questionnaire and wore an accelerometer for 1 week to measure minutes of moderate-to-vigorous physical activity before and after the 6-month intervention period.
  
  
  RESULTS
  Analysis of covariance (ANCOVA) indicated that participants in the behavioral intervention had significantly higher levels of physical activity than control participants after the 6-month period (P < .001). There was substantial interindividual variability in the magnitude of change, and ANCOVA indicated that MS type (relapsing vs. progressive) (P < .01), disability status (mild vs. moderate) (P < .01), and weight status (normal weight vs. overweight/obese) (P < .05) moderated the efficacy of the behavioral intervention.
  
  
  CONCLUSIONS
  The behavioral intervention was associated with improvements in physical activity, particularly for those with mild disability, relapsing-remitting MS, or normal weight status.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA (RWM, LAP, REK); and the Department of Kinesiology, East Carolina University, Greenville, NC, USA (DD).
authors.forename: Robert W
authors.initials: RW
authors.lastname: Motl
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA (RWM, LAP, REK); and the Department of Kinesiology, East Carolina University, Greenville, NC, USA (DD).
authors.forename: Deirdre
authors.initials: D
authors.lastname: Dlugonski
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA (RWM, LAP, REK); and the Department of Kinesiology, East Carolina University, Greenville, NC, USA (DD).
authors.forename: Lara A
authors.initials: LA
authors.lastname: Pilutti
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA (RWM, LAP, REK); and the Department of Kinesiology, East Carolina University, Greenville, NC, USA (DD).
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Klaren