title: Genetic testing before serologic screening in relatives of patients with celiac disease as a cost containment method.
abstract: OBJECTIVE
  Relatives of patients with celiac disease have an increased lifetime risk of developing celiac disease. Repeat screening of relatives would improve diagnosis rates, but at significant cost. Genetic testing before screening would potentially reduce costs by eliminating HLA-DQ2 and DQ8 negative patients who are at extremely low risk for developing celiac disease.
  
  
  METHODS
  A decision tree was developed incorporating 3 diagnostic branches: initial screening with anti-tissue transglutaminase at time t0, repeat screening at time t1, and genetic testing before repeat screening. Costs were estimated using Medicare reimbursement fees. Modeling and sensitivity analyses were performed using Tree Age Pro 2006.
  
  
  RESULTS
  The cost of an initial screening with anti-tissue transglutaminase is approximately $434 per person. Repeat screening would cost $683, but would diagnosis an additional 4.4% cases. Genetic testing before screening would cost $750, but would decrease the lower endoscopy workload by nearly 25%. Genetic testing would have to decrease from $301 to $234, a difference of $67, to justify its use before serologic testing. As the specificity of anti-tissue transglutaminase approaches 100%, the cost of genetic testing would have to continue to decrease to less than $200 in order for it to be an affordable option.
  
  
  CONCLUSIONS
  Repeat screening of relatives with celiac disease results in a significant increase in cost, but also an associated increase in cases diagnosed. Genetic testing would potentially eliminate up to 60% of the population to be screened and, if available at a lower cost, would partially offset costs of repeat serologic screening.
authors.affiliation: Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Chang
authors.forename: Peter H R
authors.initials: PH
authors.lastname: Green
mesh_terms: D002446:Celiac Disease / Q000175:diagnosis* / Q000276:immunology; D003363:Cost Control / Q000379:methods; D003663:Decision Trees; D005190:Family; D005820:Genetic Testing / Q000191:economics / Q000379:methods*; D006683:HLA-DQ Antigens / Q000235:genetics; D006801:Humans; D007349:Insurance, Health, Reimbursement / Q000191:economics; D008403:Mass Screening / Q000191:economics / Q000379:methods*; D006278:Medicare / Q000191:economics; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000191:economics* / Q000379:methods; D011503:Transglutaminases / Q000276:immunology; D014481:United States
chemical_list: D006683:HLA-DQ Antigens; C053186:HLA-DQ2 antigen; C109756:HLA-DQ8 antigen; D011503:Transglutaminases