Cost-effectiveness analysis of strategies for diagnosing celiac disease.
Dig Dis Sci 2008;
53:680-8. [PMID:
17934849 DOI:
10.1007/s10620-007-9939-5]
[Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Accepted: 07/17/2007] [Indexed: 12/09/2022]
Abstract
OBJECTIVE
To compare strategies for diagnosing celiac disease (CD).
METHODS
A decision analytic model was used to compare five strategies on diagnostic performance and costs.
RESULTS
First, tTG screening alone is the least costly strategy ($22/individual). While the NPV is high (99.8%), the PPV is low (63.4%). Second, if tTG-positive patients undergo esophagogastroduodenoscopy (EGD) to confirm CD, the PPV increases to 100% ($2,237/false-positive diagnosis avoided). Third, if EGDs are restricted to only those who are both tTG and HLA DQ2/8 positive, costs are slightly reduced ($59 vs. $63/individual), while PPV and NPV remain unchanged. Fourth, screening tTG-negative patients for IgA deficiency increases the NPV to 99.9% ($32,605/false-negative diagnosis avoided). Sensitivity analyses revealed that as the prevalence of CD increases, the cost of avoiding a false-positive diagnosis by adding EGD to the tTG alone strategy increases considerably.
CONCLUSIONS
When the pre-test probability of CD is low, patients with positive tTG serology should undergo EGD with biopsy-either directly or after positive screening for HLA DQ2/8-to confirm CD. As the pre-test probability of CD increases, the added cost of EGD should be weighed against the consequences of a false-positive diagnosis. Routinely screening for IgA deficiency in order to avoid a false-negative diagnosis is quite costly.
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