Table 2. Frequency of Unusual IFN-γ Measurements with QuantiFERON-TB Gold and QuantiFERON-TB Gold In-Tube Testing.

	QFT-Ga	QFT-GITb	Totalc	OR (95% CI)d	p value
# of tests	2741	2568	5309
# of subjects	1696	1653	1728
# (%) of tests with HNC e	136 (5.0)	98 (3.8)	234 (4.4)	1.32 (1.01–1.72)	0.042
# (%) of subjects with HNC	122	83	162
# (%) of tests with LMR f	41 (1.5)	67 (2.6)	108 (2.0)	0.57 (0. 38–0.84)	0.004
# (%) of subjects with LMR	38	59	85
# (%) of tests with VLMR g	18 (0.7)	4 (0.2)	22 (0.4)	4.24 (1.42–12.54)	0.005
# (%) of subjects with VLMR	17	4	21
# (%) of tests with VLAR h	27 (1.0)	14 (0.5)	41 (0.8)	1.82 (0.95–3.47)	0.067
# (%) of subjects with VLAR	27	14	39
# (%) of tests with any 1 or more Unusual IFN-γ Measurements	171 (6.2)	164 (6.4)	335 (6.3)
# (%) of subjects with any 1 or more Unusual IFN-γ Measurements	154	140	236

^a“QFT-G” is QuantiFERON-TB Gold test.

^b“QFT-GIT” is QuantiFERON-TB Gold In-Tube test.

^c“Total # of subjects” with unusual measurement may be less than the sum of the “# of subjects” with unusual QFT-G and QFT-GIT measurements because subjects may have unusual measurements with both tests.

^d“OR (95% CI)” is odds ratio and 95% confidence interval for an unusual IFN-γ measurement in QFT-G compared to referent, QFT-GIT.

^e“HNC” is High Nil Concentration (i.e. [Nil] over 0.7 IU/mL).

^f“LMR” is Low Mitogen Response (i.e. Mitogen Response under 0.5 IU/mL).

^g“VLMR” is Very Low Mitogen Response (i.e. Mitogen Response ≤−0.5 IU/mL).

^h“VLAR” is Very Low Antigen Response (i.e. response to a Mtb antigen ≤−0.35 IU/mL and ≤−0.5 times [Nil]).