title: Determinants of non-adherence to disease-modifying therapies in multiple sclerosis: A cross-Canada prospective study.
abstract: BACKGROUND
  Poor adherence to the disease-modifying therapies (DMTs) for multiple sclerosis (MS) may attenuate clinical benefit. A better understanding of characteristics associated with non-adherence could improve outcomes.
  
  
  OBJECTIVE
  To evaluate characteristics associated with non-adherence to injectable DMTs.
  
  
  METHODS
  Consecutive patients from four Canadian MS Clinics were assessed at three time points over two years. Clinical and demographic information included self-reported DMT use, missed doses in the previous 30 days, health behaviors, and comorbidities. Non-adherence was defined as <80% of expected doses taken. We employed generalized estimating equations to examine characteristics associated with non-adherence at all time points with findings reported as adjusted odds ratios (OR).
  
  
  RESULTS
  In all, 485 participants reported use of an injectable DMT, of whom 107 (22.1%) were non-adherent over the study period. Non-adherence was associated with a lower Expanded Disability Status Scale score (0-2.5 vs 3.0-5.5, OR: 1.80; 95% confidence interval (CI): 1.06-3.04), disease duration (⩽5 vs <5 years, OR: 2.23; 95% CI: 1.10-4.52), alcohol dependence (OR: 2.14; 95% CI: 1.23-3.75), and self-reported cognitive difficulties, measured by the Health Utilities Index-3 (OR: 1.55; 95% CI: 1.08-2.22).
  
  
  CONCLUSIONS
  Nearly one-quarter of participants were non-adherent during the study. Alcohol dependence, perceived cognitive difficulties, longer disease duration, and mild disability status were associated with non-adherence. These characteristics may help healthcare professionals identify patients at greatest risk of poor adherence.
authors.affiliation: Division of Neurology, Faculty of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Kyla A
authors.initials: KA
authors.lastname: McKay
authors.affiliation: Division of Neurology, Faculty of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Helen
authors.initials: H
authors.lastname: Tremlett
authors.affiliation: Departments of Psychiatry and Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Scott B
authors.initials: SB
authors.lastname: Patten
authors.affiliation: Departments of Psychiatry, Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada.
authors.forename: John D
authors.initials: JD
authors.lastname: Fisk
authors.affiliation: College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: Charity
authors.initials: C
authors.lastname: Evans
authors.affiliation: Departments of Critical Care Medicine & Community Health Sciences, O'Brien Institute for Public Health, and Hotchkiss Brain Institute, University of Calgary, Canada.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Fiest
authors.affiliation: School of Nursing, Faculty of Health Professions, Dalhousie University, Halifax, NS, Canada.
authors.forename: Trudy
authors.initials: T
authors.lastname: Campbell
authors.affiliation: Departments of Internal Medicine and Community Health Sciences, Health Sciences Centre, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Ruth Ann
authors.initials: RA
authors.lastname: Marrie
mesh_terms: D000328:Adult; D000368:Aged; D002170:Canada; D005260:Female; D000068717:Glatiramer Acetate / Q000627:therapeutic use*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D016899:Interferon-beta / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy*; D011446:Prospective Studies; D012306:Risk; D016896:Treatment Outcome; D055815:Young Adult; D016903:Drug Monitoring
chemical_list: D007166:Immunosuppressive Agents; D000068717:Glatiramer Acetate; D016899:Interferon-beta
keywords: Multiple sclerosis; adherence; beta-interferon; glatiramer acetate; health behavior; immunomodulatory therapy