Use of a T cell interferon gamma release assay in the investigation for suspected active tuberculosis in a low prevalence area

Table 4 Dichotomous variables; association with QFT-G results in tuberculosis patients

	QFT positive	QFT negative	Odds ratio	95% CI interval	p-value
Male	14	14	2.70	0.96 – 7.62	0.0504
Female	27	10
Origin from high or intermediate TB incidence country*	33	16	2.04	0.63 – 6.66	0.1710
Origin from low incidence country	8	8
Born abroad and lived <5 years in Sweden	14	5	1.95	0.61 – 6.96	0.1970
Born in, or lived >5 years in, Sweden	27	19
Extra pulmonary tuberculosis	19	4	4.31	1.25 – 14.87	0.0142
Pulmonary tuberculosis	22	20
Sputum smear negative**	9	6	1.62	0.38 – 7.15	0.4666
Sputum smear positive	13	14
Immunosuppressed patients ***	9	8	1.76	0.55 – 5.58	0.2357
Immune-competent patients	32	16
TST ≥ 10 mm	27	9	3.00	0.37 – 24.50	0.3000
TST < 10 mm	2	2

QFT: QuantiFERON^®-TB Gold; CI: Confidence Interval; BMI: Body Mass Index (kg/m²); TST: Tuberculin skin test
5 patients with indeterminate results excluded
* High or moderate TB-incidence is defined as ≥20 cases/100 000 population
** For pulmonary TB only (result missing in 2 patients)
*** Immune suppression defined as HIV-infection, ongoing immunosuppressive treatment, cancer, diabetes, alcohol or drug abuse

ISSN: 1471-2334