TABLE 2.

NUMBER AND PROPORTION OF POSITIVE TB TESTS AND PROPORTIONS OF POSITIVES REACTING TO BST

TB Test Type	Number Positive (% of total)*	Number (%) of Positives with BST ≥10 mm	Number (%) of Positives with Dominant BST ≥10 mm†
TST
≥10 mm	57 (3.2)‡	33 (58)	12 (21)
≥15 mm	25 (1.4)§	16 (64)	3 (12)
RSI||	48 (2.7)	28 (58)	9 (19)
T-Spot	34 (1.9)	11 (32)	4 (12)
QFT-GIT	36 (2)	8 (22)	3 (8)

Definition of abbreviations: BST = Battey skin test using purified protein derivative; QFT-GIT = QuantiFERON-TB Gold In-Tube test; TB = tuberculosis; T-Spot = T-SPOT.TB test; TST = tuberculin skin test.

^*Total population = 1,781 with determinate results by all three tests.

^†Dominant BST reaction is defined as BST reaction at least 2 mm larger than the TST reaction.

^‡TST with 10-mm cutoff had a statistically significant increased proportion of positives (P < 0.05) compared with all other TST cutoffs, QFT-GIT, and T-Spot.

^§TST with 1-mm cutoff had a statistically significant decreased proportion of positives compared with the RSI and 10-mm TST cutoffs only (P < 0.0001).

^||RSI = TST positive defined by risk stratified interpretation (30).