title: Cost-effectiveness analysis of adjunct VSL#3 therapy versus standard medical therapy in pediatric ulcerative colitis.
abstract: BACKGROUND
  Inflammatory bowel diseases (IBDs) are costly chronic gastrointestinal diseases, with pediatric IBD representing increased costs per patient compared to adult disease. Health care expenditures for ulcerative colitis (UC) are >$2 billion annually. It is not clear whether the addition of VSL#3 to standard medical therapy in UC induction and maintenance of remission is a cost-effective strategy.
  
  
  METHODS
  We performed a systematic review of the literature and created a Markov model simulating a cohort of 10-year-old patients with severe UC, studying them until 100 years of age or death. We compared 2 strategies: standard medical therapy versus medical therapy + VSL#3. For both strategies, we assumed that patients progressed through escalating therapies--mesalamine, azathioprine, and infliximab--before receiving a colectomy + ileal pouch anal anastamosis (IPAA) if the 3 medical therapy options were exhausted. The primary outcome measure was the incremental cost-effectiveness ratio (ICER), defined as the difference of costs between strategies for each quality-adjusted life-year (QALY) gained. One-way sensitivity analyses were performed on variables to determine the key variables affecting cost-effectiveness.
  
  
  RESULTS
  Standard medical care accrued a lifetime cost of $203,317 per patient, compared to $212,582 per patient for medical therapy + VSL#3. Lifetime QALYs gained was comparable for standard medical therapy and medical therapy + VSL#3 at 24.93 versus 25.05, respectively. Using the definition of ICER <50,000/QALY as a cost-effective intervention, medical therapy + VSL#3 produced an ICER of $79,910 per QALY gained, making this strategy cost-ineffective. Sensitivity analyses showed that 4 key parameters could affect the cost-effectiveness of the 2 strategies: cost of colectomy + IPAA, maintenance cost after surgery, probability of developing pouchitis after surgery, and the quality of life after a colectomy + IPAA. High surgical and postsurgical costs, a high probability of developing pouchitis, and a low quality of life after a colectomy + IPAA could make adjunct VSL#3 use a cost-effective strategy.
  
  
  CONCLUSIONS
  Given present data, adjunct VSL#3 use for pediatric UC induction and maintenance of remission is not cost-effective, although several key parameters could make this strategy cost-effective. The quality of life after an IPAA is the single most important variable predicting whether this procedure benefits patients over escalating standard medical therapy.
authors.affiliation: Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Packard Children's Hospital, Stanford University Medical Center, Palo Alto, CA 94304, USA. ktpark@stanford.edu
authors.forename: K T
authors.initials: KT
authors.lastname: Park
authors.forename: Felipe
authors.initials: F
authors.lastname: Perez
authors.forename: Raymond
authors.initials: R
authors.lastname: Tsai
authors.forename: Anita
authors.initials: A
authors.lastname: Honkanen
authors.forename: Dorsey
authors.initials: D
authors.lastname: Bass
authors.forename: Alan
authors.initials: A
authors.lastname: Garber
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000191:economics*; D001379:Azathioprine / Q000008:administration & dosage / Q000191:economics*; D002648:Child; D003082:Colectomy / Q000191:economics* / Q000379:methods; D003093:Colitis, Ulcerative / Q000473:pathology*; D003131:Combined Modality Therapy; D003362:Cost-Benefit Analysis; D017048:Health Care Costs; D006801:Humans; D000069285:Infliximab; D019804:Mesalamine / Q000008:administration & dosage / Q000191:economics*; D018803:Models, Economic; D019057:Quality-Adjusted Life Years; D016032:Randomized Controlled Trials as Topic; D059039:Standard of Care; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D019804:Mesalamine; D000069285:Infliximab; D001379:Azathioprine