Genetic Testing Prior to Serologic Screening in Family Members of Patients with Celiac Disease as a Cost Containment Method

Abstract

Purpose: Family members of patients with celiac disease (CD) have increased rates of developing CD over their lifetime, with up to 3% seroconverting 5 years after an initial negative result. Repeat testing of family members 5 years later would improve CD diagnosis rates, but at significant cost. Genetic testing prior to screening family members for CD would potentially reduce these screening costs by eliminating HLA-DQ2 and DQ8 negative patients who are at extremely low risk for developing CD. Methods: Decision analysis was used to compare the costs of screening family members of patients with CD. The decision tree incorporated three diagnostic branches: initial screening with anti-tissue transglutaminase (tTG), repeat screening with tTG at 5 years later, and genetic testing prior to screening with tTG. Costs were estimated using Medicare reimbursement fees. Modeling and sensitivity analyses were performed using Tree Age Pro 2006 (Williamstown, MA). Results: The cost of an initial screening with tTG of family members of patients with CD is approximately $434 per person. Repeat screening at 5 years later would cost $683 per person, which is an additional $249, but would diagnosis an additional 4.4% cases of CD. Genetic testing prior to screening family members would be slightly more costly, at $750 per person, but would lower endoscopy workload by nearly 25% when compared to repeat screening at 5 years without genetic testing. The cost of genetic testing would have to decrease from $301.40 to $234.40, a difference of $67, to justify its use prior to serologic testing. As the specificity of tTG 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. Conclusion: Repeat screening with tTG of family members of patients with CD results in a significant increase in cost, but also an associated increase in CD 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.