Table 4.

Comparison of QFT-GIT and T-SPOT Results for 650 HCWs after Excluding Indeterminate Cases Using Cut-off with the Inclusion of Borderline Zone.

		T-SPOT
		Positive (≥8 spot)	Borderline (5,6,7 spot)	Negative (≤4 spot)	Total
QFT-GIT
	Positive (≥0.35 IU/mL)	11	6	2	19
	Borderline (0.1 to < 0.35 IU/mL)	4	11	24	39
	Negative (<0.1 IU/mL)	1	5	586	592
Total		16	22	612	650

The QFT-GIT result was considered positive if the interferon-gamma response in the TB antigen after subtracting the response in the Nil tube was ≥0.35 IU/mL, and the T-SPOT result was considered positive if (antigen panel A minus Nil) and/or (antigen panel B minus Nil) ≥8. The QFT-GIT result was considered borderline if the interferon-gamma response in the TB antigen tube after subtracting the response in the Nil tube was (0.1 to <0.35 IU/mL), and the T-SPOT result was considered borderline if (antigen pane l A minus Nil) and/or (antigen panel B minus Nil) was 5, 6, 7. The QFT-GIT result was considered negative if the interferon-gamma response in the TB antigen tube after subtracting the response in the Nil tube was <0.1 IU/mL, and the T-SPOT result was considered negative if (antigen panel A minus Nil) and/or (antigen panel B minus Nil) was ≤4.