Tuberculin Skin Tests versus Interferon-Gamma Release Assays in Tuberculosis Screening among Immigrant Visa Applicants

Table 7

Subject characteristics associated with CXR and QFT-G discordance.

Characteristic	𝑁	CXR positive but QFT-G negative		CXR negative but QFT-G positive
		𝑛	aOR* (95% CI)	𝑛	aOR* (95% CI)
Total	1163**	164		262
Age group in years
18–20 yrs	130	8 (6.2%)	1.0	24 (18.5%)	1.0
21–30 yrs	270	7 (2.6%)	0.36 (0.12–1.02)	69 (25.6%)	1.52 (0.90–2.55)
31–40 yrs	279	18 (6.5%)	1.02 (0.43–2.43)	72 (25.8%)	1.54 (0.92–2.58)
41–50 yrs	252	47 (18.7%)	3.16 (1.44–6.95)	60 (23.8%)	1.38 (0.82–2.34)
51–64 yrs	189	64 (33.9%)	7.60 (3.49–16.53)	35 (18.5%)	1.004 (0.565–1.784)
≥65 yrs	43	20 (14.1%)	13.26 (5.22–33.72)	2 (4.7%)	0.215 (0.05–0.95)
Prior TB
No	1157	160 (13.8%)	1.0	262 (22.7%)
Yes	6	4 (66.7%)	16.26 (2.42–109.33)	0 (0.0%)	N.S. and NIM
Chest exam
Normal	1157	160 (13.8%)	1.0	262 (22.7%)
Abnormal	6	4 (66.7%)	20.81 (2.76–156.68)	0 (0.0%)	N.S. and NIM

CXR: chest radiograph; QFT-G: QuantiFERON-TB Gold; 𝑛: number in subset of 𝑁; aOR: adjusted Odd Ratio; 95% CI: 95% confidence interval; TB: tuberculosis; N.S.: Not Significant; NIM: Not in model.
*Multivariate models were created using factors with 𝑃-values ≤0.2 in univariate analysis and <0.05 in stepwise logistic regression until the best fitting, parsimonious model was identified. Model fit was evaluated using the Hosmer-Lemeshow test. Bold font indicates statistically significant adjusted odds ratios (aORs).
**Data from 83 subjects with indeterminate QFT-G results were excluded from analysis.