title: Longitudinal variations and predictors of increased perceived impact of multiple sclerosis, a two-year study.
abstract: OBJECTIVE
  To explore variations and the capacity of selected factors - contextual factors, disease-related characteristics, cognition, fatigue, mood and time - to predict an increase in the perceived physical and psychological impact of multiple sclerosis (MS) over a two-year period.
  
  
  METHODS
  At an MS specialist clinic, 219 outpatients were included in the study and data were collected every 6 months. The Multiple Sclerosis Impact Scale was used for assessment of the perceived physical and psychological impact of MS. For statistical analysis of changes in impact during the study period, Friedman ANOVA was used and predictors of increased impact were explored with Generalized Estimating Equations employing proportional odds models.
  
  
  RESULTS
  The majority had changes in perceived physical impact of established important magnitude and the psychological impact varied significantly. A period of more than 10 years since diagnosis, cognitive disability, fatigue and signs of depression were independent predictors of increase in physical impact. Weak or moderate sense of coherence, absence of immunomodulatory treatment, fatigue and signs of depression were independent predictors of increase in psychological impact.
  
  
  CONCLUSIONS
  The fluctuation in perceived impact should be taken into account in clinical decision-making and when designing studies and interpreting the results. This study identifies the predictors of increased perceived physical and psychological impact that health-related services should pay special attention to, in order to provide interventions aimed at minimizing the perceived impact of MS.
authors.affiliation: Department of Clinical Neuroscience, Care Sciences and Society, Karolinska University Hospital, Huddinge, 141 86 Stockholm, Sweden. charlotte.ytterberg@ki.se
authors.forename: Charlotte
authors.initials: C
authors.lastname: Ytterberg
authors.forename: Sverker
authors.initials: S
authors.lastname: Johansson
authors.forename: Lotta Widén
authors.initials: LW
authors.lastname: Holmqvist
authors.forename: Lena
authors.initials: L
authors.lastname: von Koch
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002648:Child; D003071:Cognition; D016001:Confidence Intervals; D004185:Disability Evaluation; D004644:Emotions; D005221:Fatigue; D005260:Female; D006801:Humans; D007389:Internal-External Control; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology* / Q000523:psychology*; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D018434:Sickness Impact Profile; D013997:Time Factors