title: Cost-effectiveness of 5-aminosalicylic acid therapy for maintenance of remission in ulcerative colitis.
abstract: OBJECTIVE
  Oral 5-aminosalicylic acid (5-ASA, mesalamine) is effective in inducing and maintaining remission in ulcerative colitis (UC). The relative benefits and costs of maintenance 5-ASA therapy are uncertain. Our aims were to evaluate this strategy's potential cost-effectiveness.
  
  
  METHODS
  We constructed a Markov model to compare two strategies over 2 yr: (a) no maintenance 5-ASA, with 5-ASA 4.8 g/day given for flares, (b) maintenance 5-ASA 2.4 g/day, escalated and maintained at 4.8 g/day after the first flare. In both arms, the failure to induce remission led to other treatments, as needed: prednisone, parenteral corticosteroids, cyclosporine, 6-mercaptopurine, infliximab, and colectomy.
  
  
  RESULTS
  Without maintenance 5-ASA, the mean flares per person were 1.92, and the mean cost per person was $3,402. With maintenance 5-ASA providing a relative risk of flare of 0.7 at 5-ASA cost of $198/month, flares per person decreased to 1.38 at a cost of $8,810/flare prevented. Maintenance 5-ASA increased discounted quality-adjusted life-years per person (QALYs per person) from 1.75 to 1.77 at a discounted cost of $224,000/QALY gained. The results were most sensitive to the flare risk reduction and cost of 5-ASA, the utilities of being in remission without or with 5-ASA, and the colectomy rates. At $15/month (the cost of sulfasalazine), maintenance 5-ASA cost $640/flare prevented and $16,300/QALY gained.
  
  
  CONCLUSIONS
  Maintenance 5-ASA therapy decreases UC flares, but its cost may be substantial, depending on society's willingness to pay. If sulfasalazine can be tolerated and yields comparable benefits, sulfasalazine maintenance therapy is likely to be cost-effective. The cost per QALY gained by 5-ASA maintenance is highly dependent on the quality of life while taking versus not taking maintenance 5-ASA, highlighting the importance of patients' preferences.
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of California, San Francisco, San Francisco, California 94143-0538, USA.
authors.forename: Eugene F
authors.initials: EF
authors.lastname: Yen
authors.forename: Sunanda V
authors.initials: SV
authors.lastname: Kane
authors.forename: Uri
authors.initials: U
authors.lastname: Ladabaum
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000191:economics*; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000191:economics*; D003362:Cost-Benefit Analysis; D006801:Humans; D008390:Markov Chains; D019804:Mesalamine / Q000008:administration & dosage / Q000191:economics*; D018803:Models, Economic; D019057:Quality-Adjusted Life Years; D012074:Remission Induction; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D019804:Mesalamine