Table 8– Summary specificity of interferon-γ release assays and the tuberculin skin test (TST)
SeriesDiagnosticsSubjectStudies nSummary specificity (96% CI)Specificity range
1QFT-G/G-ITHealthy young adults120.98 (0.97–0.99)0.92–1.00
2QFT-G/G-ITHealthy young adults, BCG-80.99 (0.98–1.00)0.95–1.00
3QFT-G/G-ITHealthy young adults, BCG+80.96 (0.94–0.98)0.89–0.99
4T.SPOTPredominantly BCG vaccinated80.93 (0.86–1.00)0.85–1.00
5TSTBCG not vaccinated60.97 (0.95–0.99)0.93–1.00
6TSTBCG vaccinated60.59 (0.46–0.73)0.35–0.79
  • Several studies under series 1 are included in series 2 or 3. QFT-G: QuantiFERON®-TB Gold; QFT-G-IT: QuantiFERON®-TB Gold In-Tube; T.SPOT: T.SPOT-TB®; TB: tuberculosis. Data are taken from the meta-analysis in 109.