Table 2. Agreement of QFT-G, QFT-PD, and QFT-PT and Comparison of QFT-P assay IFN-γ values by blood collection method.

QFT Results
Overall (N = 299)	% agreement	95% CI	kappa	95% CI
Cutoff Positive ≥0.35 IU/mL
QFT Gold versus QFT+ Direct	91	88–94	0.56	0.41–0.71
QFT Gold versus QFT+ Transfer	91	87–94	0.59	0.46–0.73
QFT+ Direct versus QFT+ Transfer	85		80–89	0.37
Cutoff Positive >0.7 IU/mL
QFT Gold versus QFT+ Direct	93	90–96	0.55	0.37–0.72
QFT Gold versus QFT+ Transfer	94	90–96	0.55	0.37–0.73
QFT+ Direct versus QFT+ Transfer	92	87–95	0.5	0.32–0.67
TST Positive (N = 131)
QFT Gold versus QFT+ Direct	93	87–97	0.72	0.55–0.89
QFT Gold versus QFT+ Transfer	90	84–95	0.61	0.43–0.80
QFT+ Direct versus QFT+ Transfer	86	79–92	0.51	0.32–0.71