Table 2

Sensitivity analysis for incremental cost effectiveness of strategies

StrategyCost ($)Incremental costs ($)QALYsIncremental QALYsICER ($/QALY)
Sensitivity analysis 1
 TST81617.641
 TST only822617.6430.00193082
 Dual-test strategy102620417.6590.015713 023
Sensitivity analysis 2
 TST positive, IGRA74217.623
 TST only8278417.6370.01445858
 Dual-test strategy92810117.6540.01666078
Sensitivity analysis 3
 TST positive, IGRA78517.641
 Dual-test strategy93615117.6590.01768598
  • Dominated strategies are excluded. All costs are in Singapore dollars ($).

  • Sensitivity analysis 1: varied IGRA sensitivity=0.89; IGRA specificity=0.95; TST sensitivity=0.85; TST specificity=0.8; IGRA cost=$156; TST cost=$22 (meta-analyses15).

  • Sensitivity analysis 2: varied IGRA sensitivity=0.64; IGRA specificity=0.995; TST sensitivity=0.69; TST specificity=0.74; IGRA cost=$66; TST cost=$22 (prospective data).

  • Sensitivity analysis 3: varied from analysis 1 with IGRA cost=$66; TST cost=$22.

  • Dual-test strategy, TST and IGRA tests performed simultaneously; ICER, incremental cost-effectiveness ratio; IGRA, interferon-γ release assay; QALY, quality-adjusted life year; TST, tuberculin skin test; TST positive, IGRA, IGRA following a positive TST result strategy.