title: The impact of the type of insurance plan on adherence and persistence with antidepressants: a matched cohort study.
abstract: OBJECTIVE
  To compare adherence to, and persistence with, antidepressants (AD) in Quebec patients who are covered by private and public drug insurance.
  
  
  METHODS
  A matched cohort study was conducted using prescription claims databases: reMed, a medication data registry for Quebec residents covered by private drug insurance, and Régie de l'assurance maladie du Québec database for Quebec residents with public drug insurance. Patients were aged 18 to 64 years and filled at least 1 prescription for an AD in monotherapy between December 2007 and September 2009 (194 privately and 2055 publicly insured patients). Adherence over 1 year was estimated using the proportion of prescribed days covered (PPDC). The difference in mean PPDC between patients with private and public drug insurance was estimated with linear regression. Persistence was compared between the groups with a Cox regression model.
  
  
  RESULTS
  The PPDC was 86.4% (95% CI 83.3% to 89.5%) in privately insured and 82.2% (95% CI 78.5% to 85.9%) in publicly insured patients and the adjusted mean difference was 5.1% (95% CI 1.6% to 8.6%). Persistence was 51.0% in the private group and 19.7% in the public group at 1 year (P < 0.001); the adjusted hazard ratio was 0.49 (95% CI 0.30 to 0.79).
  
  
  CONCLUSIONS
  Better adherence and persistence were observed in privately insured patients. Adherence difference may be due to lower copayment among privately insured patients.
authors.affiliation: Université de Montréal, Montreal, Quebec.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Assayag
authors.forename: Amélie
authors.initials: A
authors.lastname: Forget
authors.forename: Fatima-Zohra
authors.initials: FZ
authors.lastname: Kettani
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Beauchesne
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Moisan
authors.forename: Lucie
authors.initials: L
authors.lastname: Blais
mesh_terms: D000293:Adolescent; D000328:Adult; D000928:Antidepressive Agents / Q000191:economics* / Q000627:therapeutic use; D015331:Cohort Studies; D016208:Databases, Factual; D003866:Depressive Disorder / Q000188:drug therapy / Q000191:economics*; D005260:Female; D006264:Health Benefit Plans, Employee / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D007356:Insurance, Pharmaceutical Services / Q000706:statistics & numerical data*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000191:economics / Q000706:statistics & numerical data*; D011306:Prescription Fees / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D011792:Quebec; D012107:Research Design; D012189:Retrospective Studies; D055815:Young Adult; D016903:Drug Monitoring
chemical_list: D000928:Antidepressive Agents