Table 3. Number and percentage (95% CI) of indeterminate results, number of positive and interpretable results and sensitivity rates (percentage; 95% CI) of QuantiFERON® Gold in Tube (QFT-GIT) in groups of individuals without active TB at varying risks of M. tuberculosis exposure.

Individuals at varying risks of TB exposure	Healthy community adults		Health CareWorkers	Healthy familycontacts	Cured TBpatients	Total non- activeTB subjects
	HIV-uninfected(N = 55)	HIV-infected(N = 54)	(N = 5)	(N = 54)	(N = 12)	(n = 180)
N of Indeterminate Results	0	6	0	1	0	7
Percentage of Indeterminate Results(CI 95%)	0.0 (0.0–6.8)	11.1 (5.1–22.5)	0.0 (0.0–44.4)	1.9 (0.3–10.2)	0.0 (0.0–25.0)	3.9 (1.6–7.8)
N of positive results(a)/N of interpretable results(b)	23/55	19/48	3/5	33/53	11/12	89/173
Clinical sensitivity (%; 95% CI)(c)	41.8 (28.7–55.9)	35.2 (22.7–49.4) (p = 0.5563)	60.0 (14.6–94.7) (p = 0.6439)	61.1 (46.9–74.1) (p = 0.0559)	91.7 (61.5–99.8) (p = 0.0028)	49.3 (41.9–57.0)
Laboratory sensitivity (%; 95% CI)(d)	41.8 (29.5–55.2)	39.6 (26.8–54.0) (p = 0.8432)	60.0 (14.6–94.7) (p = 0.6439)	62.3 (47.9–75.2) (p = 0.0367)	91.7 (61.5–99.8) (p = 0.0028)	51.5 (43.7–59.1)

Footnotes: QFT-GIT: QuantiFERON® Gold in Tube; HIV: human immunodeficiency virus; TB: tuberculosis.

^(a)QFT-GIT with specific antigen cut –off point: 0.35 IU/mL.

^(b)QFT-GIT with PHA cut –off point: 0.50 IU/mL.

^(c)Clinical sensitivity: overall sensitivity calculated on the total of patients tested (indeterminate results included as negative).

^(d)Laboratory sensitivity: sensitivity calculated only on the interpretable results (indeterminate results excluded).