Table 2. Combinations of smear microscopy, reference standard and MTB/RIF results within eligible patients.

Number of patients (%)*	Reference standard		Index test(MTB/RIF)	Smearmicroscopy	Comment
	Löwenstein- Jensen	MGIT
30 (22.4)	+	+	+	+	full agreement
13 (9.7)	+	+	+	–	false negative smear
1 (0.7)	+	+	–	–	false negative MTB/RIF and smear
1 (0.7)	–	–	+	+	false positive MTB/RIF and smear
2 (1.5)	–	–	–	+	false positive smear
1 (0.7)	–	–	+	–	false positive MTB/RIF
1 (0.7)	–	+	+	+	false negative LJ
82 (61.2)	–	–	–	–	full agreement
1 (0.7)	contaminated	contaminated	–	–	contaminated reference standard
2 (1.5)	–	–	invalid	–	invalid MTB/RIF

Löwenstein-Jensen = LJ; MGIT = Mycobacteria Growth Indicator Tube; MTB/RIF = Xpert®MTB/RIF;

<$>\raster="rg2"<$> = positive result; <$>\raster="rg3"<$> = negative result; LJ and MGIT: composite reference standard.

^*Two eligible patients were excluded because they did not provide a second sputum sample.