Screening health care workers with interferon-γ release assay versus tuberculin skin test: Impact on costs and adherence to testing (the SWITCH study)

OBJECTIVE: To determine the price point at which an interferon-γ release assay (IGRA) is less costly than a tuberculin skin test (TST) for health care employee tuberculosis screening. METHODS: A multidecision tree-based cost model incorporating inputs gathered from time-motion studies and parallel testing by IGRA and TST was conducted in a subset of our employees. RESULTS: Administering a TST testing program costs $73.20 per person screened, $90.80 per new hire, and $63.42 per annual screen. Use of an IGRA for employee health testing is cost saving at an IGRA test cost of $54.83 or less per test and resulted in higher completion rates because of the elimination of the need for a second visit to interpret the TST. CONCLUSIONS: Using an IGRA for employee health screening can be an institutional cost saving and results in higher compliance rates.