title: What does a structured review of the effectiveness of exercise interventions for persons with multiple sclerosis tell us about the challenges of designing trials?
abstract: OBJECTIVE
  The goal of this review is to ascertain the extent to which the current body of research on the role of exercise in multiple sclerosis (MS) provides sufficiently strong evidence to guide regular exercise prescription.
  
  
  METHODS
  We searched CINAHL, COCHRANE, EMBASE, and MEDLINE between 1950 and December 2007 with combinations of MeSH terms and keywords. We assessed the methodological quality of selected randomized controlled trials (RCTs) of exercise interventions using the Physiotherapy Evidence Database scale and evaluated the effects of the exercise interventions by calculating effect sizes (ES) for the target outcomes.
  
  
  RESULTS
  Eleven RCTs met the criteria, all with acceptable methodological quality. The ES ranged from -0.36 to 3.50 on the target outcomes. Only one study had 95% confidence intervals clearly excluding a value of 0. Measures of body functions and structures and activities were the most common target outcomes of interventions.
  
  
  CONCLUSIONS
  Although there was some evidence to support positive effects of exercise on physical and psychosocial functioning and on quality of life, our review revealed insufficient research in this area, making it difficult to guide regular exercise prescription. Furthermore, it also emphasizes the methodological challenges in these RCTs leading us to believe that there is a great need for high quality RCTs in this area, contributing evidence for regular exercise and physical activity prescription for persons with MS.
authors.affiliation: Division of Clinical Epidemiology, McGill University Health Centre, Montreal, QC, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Asano
authors.forename: D J
authors.initials: DJ
authors.lastname: Dawes
authors.forename: A
authors.initials: A
authors.lastname: Arafah
authors.forename: C
authors.initials: C
authors.lastname: Moriello
authors.forename: N E
authors.initials: NE
authors.lastname: Mayo