Table 2

Characteristics Associated with Negative Interferon-γ Release Assay Results in Culture-Confirmed Tuberculosis Patients, Texas, USA, 2013–2015

Duc T. Nguyen, Larry D. Teeter, Julie Graves, and Edward A. Graviss

Author affiliations: Houston Methodist Research Institute, Houston, Texas, USA (D.T. Nguyen, E.A. Graviss); Forensic Research and Analysis, Portland, Oregon, USA (L.D. Teeter); University of Medicine and Health Sciences, New York, New York, USA (J. Graves); University of Texas School of Public Health, Houston (J. Graves)

Main Article

Crude association between negative IGRA results and culture-confirmed TB patient characteristics, Texas, USA, 2013–2015*

Variable	Positive IGRA, n = 1,304	Negative IGRA, n = 183	Crude OR (95% CI)	p value
Age, y, median (IQR)	46 (29–60)	55 (40–68)	1.02 (1.01–1.03)	<0.001
Age >60 y	326 (25.0)	76 (41.5)	2.13 (1.55–2.93)	<0.001
Sex
F	479 (36.7)	66 (36.1)	Reference
M	825 (63.3)	117 (63.9)	1.03 (0.75–1.42)	0.861
Non-Hispanic white	116 (8.9)	36 (19.7)	2.50 (1.66–3.77)	<0.001
US born	505 (38.7)	85 (46.4)	1.37 (1.01–1.87)	0.046
Homeless	85 (6.5)	15 (8.2)	1.28 (0.72–2.27)	0.40
Resident of correction institution	50 (3.8)	4 (2.2)	0.56 (0.20–1.57)	0.27
Resident of long-term care facility	18 (1.4)	2 (1.1)	0.79 (0.18–3.43)	0.75
Injection drug user	35 (2.7)	3 (1.6)	0.60 (0.18–1.99)	0.41
Excessive alcohol user	218 (16.7)	39 (21.3)	1.35 (0.92–1.98)	0.13
Contact with TB patient within past 2 y	73 (5.6)	3 (1.6)	0.28 (0.09–0.90)	0.03
Received TNF-α antagonist therapy	2 (0.2)	1 (0.5)	3.58 (0.32–39.64)	0.30
Solid organ transplant recipient	1 (0.1)	1 (0.5)	7.16 (0.45–114.96)	0.17
Diabetes	265 (20.3)	39 (21.3)	1.06 (0.73–1.55)	0.76
Chronic kidney disease	16 (1.2)	3 (1.6)	1.34 (0.39–4.65)	0.64
Immunosuppression	30 (2.3)	7 (3.8)	1.69 (0.73–3.90)	0.22
Previous TB	31 (2.4)	1 (0.5)	0.23 (0.03–1.66)	0.14
Chest radiograph result
Normal	137 (10.5)	23 (12.6)	Reference
Consistent with TB	1,092 (83.7)	148 (80.9)	0.81 (0.50–1.30)	0.38
Unknown/Not done	75 (5.8)	12 (6.6)	0.95 (0.45–2.02)	0.90
TB site
Pulmonary	997 (76.5)	139 (76.0)	Reference
Extrapulmonary	169 (13.0)	27 (14.8)	1.15 (0.74–1.79)	0.55
Both	138 (10.6)	17 (9.3)	0.88 (0.52–1.51)	0.65
HIV status
Negative	1,134 (87.0)	145 (79.2)	Reference
Positive	70 (5.4)	20 (10.9)	2.23 (1.32–3.78)	0.003
Unknown/Not done	100 (7.7)	18 (9.8)	1.41 (0.83–2.39)	0.21
Epidemiologically linked	118 (9.0)	8 (4.4)	0.46 (0.22–0.96)	0.04
Tested by T-SPOT.TB	436 (33.4)	76 (41.5)	1.41 (1.03–1.94)	0.03
IGRA sample collected after TB treatment initiated	415 (31.8)	74 (40.4)	1.45 (1.06–20)	0.02
MDR	12 (0.9)	1 (0.5)	0.59 (0.08–4.58)	0.62
Genotyped	1,260 (96.6)	175 (95.6)	0.76 (0.35–1.65)	0.49
East Asian family lineage	231 (17.7)	27 (14.8)	0.80 (0.52–1.24)	0.32
Clustered	555 (44.1)	85 (48.6)	1.20 (0.87–1.65)	0.26
GENType G00010	34 (2.6)	6 (3.3)	1.27 (0.52–3.06)	0.60
Days from diagnosis to treatment initiation, median (IQR)	2.0 (0–12.0)	5.0 (0.5–26.0)	1.00 (1.00–1.01)	0.04
Follow-up, mo, median (IQR)†	9.4 (7.3–10.7)	9.2 (7.0–10.7)	0.96 (0.92–1.01)	0.11
Year of diagnosis
2013	373 (28.6)	56 (30.6)	Reference
2014	428 (32.8)	53 (29.0)	0.82 (0.55–1.23)	0.35
2015	503 (38.6)	74 (40.4)	0.98 (0.68–1.42)	0.92

*Values are no. (%) unless otherwise indicated. GENType, tuberculosis genotype; IGRA, interferon-γ release assay; IQR, interquartile range; MDR, multidrug resistance; OR, odds ratio; TB, tuberculosis; TNF-α, tumor necrosis factor α.
†From diagnosis date until the end of treatment or patient death, whichever came first.

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Page created: February 15, 2018

Page updated: February 15, 2018

Page reviewed: February 15, 2018

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