Table 2.

Agreement between reactors of tuberculin skin tests and antibovine tuberculosis antibody assay according to various tuberculin skin response cutoff points.

	SICCT-BT cutoff points						SIT-BT
	≥4 mm		≥3 mm		≥2 mm		≥4 mm
	Number	%	Number	%	Number	%	Number	%
TST positive/Anti-BTB Ab positive	29	3.59	64	7.93	76	9.42	81	10.04
TST negative#/Anti-BTB Ab positive	271	34.82	236	29.24	224	27.76	219	27.14
TST positive/Anti-BTB Ab negative	0	0	8	0.99	19	2.35	25	3.10
TST negative#/Anti-BTB Ab negative	507	62.83	499	61.83	488	60.47	482	59.73
Total	807		807		807		807
Agreement	29/807	3.59	64/807	7.93	76/807	9.42	81/807	10.04
Kappa statistics*	0.119		0.234		0.251		0.254

TST: Tuberculin skin test.

Anti-BTB Ab: antibovine tuberculosis antibody assay.

^#Not TST positive including TST doubtful reactors.

*Kappa ranges from 1 (complete agreement beyond chance) to 0 (agreement is equal to that expected by chance), whereas negative values indicate that agreement less than that is expected by chance.