Cost-effectiveness analysis of targeted and sequential screening strategies for latent tuberculosis

SETTING: No cost-effectiveness studies of testing for latent tuberculosis infection have incorporated both targeted testing and the use of interferon-gamma release assays (IGRAs) in heterogeneous populations. OBJECTIVE: To examine the cost-effectiveness of universal vs. targeted and sequential testing strategies and the use of tuberculin skin testing (TST) vs. IGRAs. DESIGN: Using a decision-analytic model, incremental cost-effectiveness ratios were calculated in 2009 among nine potential strategies for screening recruits. A societal perspective was taken over a 20-year analytic horizon, discounting future costs at 3% annually. Sensitivity analyses were conducted to determine how changes in assumptions affected the estimates. RESULTS: Targeted strategies cost over US$250 000 per case prevented, whereas universal testing strategies cost over US$700 000 per incremental case prevented in base case and most sensitivity analyses. CONCLUSION: Targeted testing offered the best value in this population, although it was still relatively expensive compared to no testing. Sequential testing with both TST and IGRAs provided a poor incremental value compared to targeted and universal testing strategies. Targeted testing using TST was slightly more cost-effective than targeted testing using either QuantiFERON® -TB Gold In-Tube or T-SPOT® .TB, but these estimates were very sensitive to changes in model assumptions.