Table 3.

Concordance between the two commercial IGRAs stratified by study visit

Visit no. (study day)No. of subjects per visitNo. (%) of positive QFT resultsNo. (%) of positive T-SPOT resultsNo. (%) of discordant IGRA resultsAgreement between QFT and T-SPOT results
Raw (%)Kappa (P)
1 (0)3512 (34.3)10 (28.6)8 (22.9)77.10.47 (0.005)
2 (+7)3512 (34.3)10 (28.6)6 (17.1)82.90.60 (<0.001)
3 (+14)307 (23.3)7 (23.3)2 (6.7)93.30.81 (<0.001)
4 (+21)315 (16.1)5 (16.1)2 (6.5)93.50.76 (<0.001)
5 (+28)274 (14.8)4 (14.8)2 (7.4)92.60.71 (<0.001)
Total15840 (25.3)36 (22.8)20 (12.7)87.30.65 (<0.001)