Table 4

The impact of alternative assumptions for test properties and latent tuberculosis infection rates (societal perspective)

Incremental cost-effectiveness ratios (US$ per life year saved)
No testTSTIGRA after (+) TSTIGRA after (−) TSTIGRA
0–2-year-old cohort base-case estimates1*(Dominated)(Dominated)(Dominated)(Dominated)
 LTBI rates (%)
  81*(Dominated)(Dominated)(Dominated)(Dominated)
  481*(Dominated)(Dominated)183812 (QFT), 246342 (TSPOT)(Dominated)
 TST sensitivity
  751*(Dominated)(Dominated)1532062 (QFT), 1456062(TSPOT)(Dominated)
  931*(Dominated)(Dominated)(Dominated)(Dominated)
 TST specificity
  621*(Dominated)(Dominated)(Dominated)(Dominated)
  881*(Dominated)(Dominated)(Dominated)(Dominated)
 QFT sensitivity
  751*(Dominated)(Dominated)(Dominated)(Dominated)
  921*(Dominated)(Dominated)(Dominated)(Dominated)
 QFT specificity
  781*(Dominated)(Dominated)(Dominated)(Dominated)
  1001*(Dominated)(Dominated)(Dominated)(Dominated)
3–5 year old cohort Base-case estimates1*(Dominated)(Dominated)2335262 (QFT), 2542432 (TSPOT)(Dominated)
 LTBI rates (%)
  231*(Dominated)(Dominated)(Dominated)(Dominated)
  621*(Dominated)(Dominated)681222 (QFT) 752982 (TSPOT)(Dominated)
 TST sensitivity
  751*(Dominated)(Dominated)415682 (QFT), 451562 (TSPOT)(Dominated)
  931*(Dominated)(Dominated)(Dominated)(Dominated)
 TST specificity
  621*(Dominated)(Dominated)6154902 (QFT), 6782542(TSPOT)(Dominated)
  881*(Dominated)(Dominated)1645502 (QFT), 1796972(TSPOT)(Dominated)
 QFT sensitivity
  751*(Dominated)(Dominated)2303352 (QFT), 252,8602 (T-SPOT)(Dominated)
  921*(Dominated)(Dominated)2333262 (QFT), 2550652(TSPOT)(Dominated)
 QFT specificity
  781*(Dominated)(Dominated)2320232 (QFT), 2541562(TSPOT)(Dominated)
  1001*(Dominated)(Dominated)2320232 (QFT), 2541562(TSPOT)(Dominated)
  • * The superscript 1 indicates the most cost-effective strategy while 2 indicates a more effective, but less cost-effective strategy. Incremental cost-effectiveness ratios are provided for both types of IGRAs when the no-test strategy does not dominate.

  • The single IGRA strategy is dominated by the IGRA after negative TST strategy. In all other instances, strategies are dominated by the no-testing strategy.

  • Cost of IGRA after positive TST strategy becomes the most costly strategy. All strategies remain dominated by the no-testing strategy.

  • IGRA, interferon γ release assay; LTBI, latent tuberculosis infection; QFT, QuantiFERON assay, TSPOT, T-SPOT.TB; TST, tuberculin skin test.