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

Abstract

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. To examine the cost-effectiveness of universal vs. targeted and sequential testing strategies and the use of tuberculin skin testing (TST) vs. IGRAs. 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. 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. 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.