title: Cost-effectiveness analysis of genotyping for HLA-B*5801 and an enhanced safety program in gout patients starting allopurinol in Singapore.
abstract: OBJECTIVE
  Allopurinol is an efficacious urate-lowering therapy (ULT), but is associated with rare serious adverse drug reactions of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with higher risk among HLA-B*5801 carriers. We assessed the cost-effectiveness of HLA-B*5801 testing, an enhanced safety program or strategies with both components.
  
  
  METHODS
  The analysis adopted a health systems perspective and considered Singaporean patients with chronic gout, over a lifetime horizon, using allopurinol or probenecid. The model incorporated SJS/TEN and gout treatment outcomes, allele frequencies, drug prices and other medical costs.
  
  
  RESULTS
  Based on cost-effectiveness threshold of US$50,000 per quality-adjusted life year, HLA-B*5801-guided ULT selection or enhanced safety program was not cost effective. Avoidance of ULTs was the least preferred strategy as uncontrolled gout leads to lower quality-adjusted life years and higher costs.
  
  
  CONCLUSIONS
  The analysis underscores the need for biomarkers with higher positive predictive value for SJS/TEN, less expensive genetic tests or safety programs, or more effective gout drugs. .
authors.affiliation: Health Services & Systems Research Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: Di
authors.initials: D
authors.lastname: Dong
authors.affiliation: Vigilance & Compliance Branch, Health Sciences Authority, 11 Biopolis Way, #11-01, Helios, Singapore 138667, Singapore.|Saw Swee Hock School of Public Health, National University of Singapore, Tahir Foundation Building, 12 Science Drive 2, #10-01, Singapore 117549, Singapore.
authors.forename: Wei-Chuen
authors.initials: WC
authors.lastname: Tan-Koi
authors.affiliation: Division of Rheumatology, National University Health System, University Medicine Cluster, Singapore.|Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Gim Gee
authors.initials: GG
authors.lastname: Teng
authors.affiliation: Health Services & Systems Research Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: Eric
authors.initials: E
authors.lastname: Finkelstein
authors.affiliation: Vigilance & Compliance Branch, Health Sciences Authority, 11 Biopolis Way, #11-01, Helios, Singapore 138667, Singapore.|Emerging Infectious Diseases Program, Duke-NUS Graduate Medical School, 8 College Road, Singapore 169857, Singapore.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Sung
mesh_terms: D000493:Allopurinol / Q000191:economics* / Q000627:therapeutic use; D003362:Cost-Benefit Analysis / Q000379:methods*; D005838:Genotype; D060005:Genotyping Techniques / Q000191:economics*; D006073:Gout / Q000188:drug therapy / Q000191:economics* / Q000453:epidemiology / Q000235:genetics; D006074:Gout Suppressants / Q000191:economics / Q000627:therapeutic use; D015235:HLA-B Antigens / Q000191:economics* / Q000235:genetics; D006801:Humans; D061214:Patient Safety / Q000191:economics*; D012846:Singapore / Q000453:epidemiology
chemical_list: D006074:Gout Suppressants; D015235:HLA-B Antigens; C500126:HLA-B*58:01 antigen; D000493:Allopurinol
keywords: HLA-B*5801 genotyping; Stevens–Johnson syndrome; cost–effectiveness; gout; safety monitoring; toxic epidermal necrolysis