title: Glatiramer acetate versus interferon beta-1a for subcutaneous administration: comparison of outcomes among multiple sclerosis patients.
abstract: BACKGROUND
  We compared the outcomes of multiple sclerosis (MS) patients treated with either glatiramer acetate (GA) (Copaxone, Teva Pharmaceutical Industries, Israel) or interferon beta-1a for subcutaneous administration (IFN beta-1a-SC) (Rebif, Merck Serono, Switzerland).
  
  
  METHODS
  Data were obtained from i3's Lab Rx Database from July 2001 to June 2006. We established an 'intent-to-treat' (ITT) cohort (n=845) of patients diagnosed with MS who began therapy on either GA (n=542) or IFN beta-1a-SC (n=303) and had continuous insurance coverage from 6 months before to 24 months after the date they began taking the medication. We also created a 'continuous use' (CU) cohort (n=410) of individuals who, in addition to the criteria listed above, used either GA or IFN beta-1a-SC within 28 days of the end of the 2-year-post period. Using multivariate regressions, we examined both the 2-year total direct medical costs and the likelihood of relapse associated with the use of these two MS medications. We defined relapse as either being hospitalised with a diagnosis of MS, or being diagnosed with MS during an outpatient visit and then prescribed steroids within a 7-day period. All regressions controlled a wide range of factors that have potentially affected outcomes.
  
  
  RESULTS
  In the ITT cohort, patients who started therapy on GA had a significantly lower 2-year risk of relapse (5.92% versus 10.89%; P=0.0305), as well as significantly lower 2-year total medical costs (US$41,786 versus US$49,030; P=0.0002). In the CU cohort, patients who used GA also had a significantly lower 2-year risk of relapse (1.94% versus 9.09%; P=0.0049) and significantly lower total medical costs (US$45,213 versus US$57,311; P<0.0001).
  
  
  CONCLUSIONS
  Results indicate that, compared with the use of IFN beta-1a-SC, use of GA is associated with significantly lower probability of relapse as well as significantly lower 2-year total direct medical costs. In addition, these results are more pronounced among patients defined as continuous users.
authors.affiliation: Teva Neuroscience, Kansas City, Missouri, USA.
authors.forename: Jane
authors.initials: J
authors.lastname: Castelli-Haley
authors.forename: MerriKay
authors.initials: M
authors.lastname: Oleen-Burkey
authors.forename: Merry-Kay A
authors.initials: MK
authors.lastname: Oleen-Burkey
authors.forename: Maureen J
authors.initials: MJ
authors.lastname: Lage
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Johnson
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D000328:Adult; D015331:Cohort Studies; D003365:Costs and Cost Analysis; D004334:Drug Administration Schedule; D005260:Female; D000068717:Glatiramer Acetate; D006801:Humans; D007279:Injections, Subcutaneous; D000068556:Interferon beta-1a; D016899:Interferon-beta / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D008297:Male; D009103:Multiple Sclerosis / Q000188:drug therapy*; D010455:Peptides / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D012008:Recurrence; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000276:Adjuvants, Immunologic; D010455:Peptides; D000068717:Glatiramer Acetate; D016899:Interferon-beta; D000068556:Interferon beta-1a