Table 2. Diagnostic accuracy of LF-LAM among HIV clinic attendees with CD4<200.

	Prevalence of TB		Prevalence of positive LAM		Sensitivity		Specificity		PPV		NPV
Gold standard = confirmed* and clinical† TB	n/N	%	n/N	%	n/N	% (95% CI)	n/N	% (95% CI)	n/N	% (95% CI)	n/N	% (95% CI)
Grade 1‡ cut-off	56/424	13.2%	24/424	5.7%	8/56	14.3% (6.4, 26.2)	352/368	95.7% (93.0, 97.5)	8/24	33.3% (15.6, 55.3)	352/400	88.0% (84.4, 91.0)
CD4 <100	35/187	18.7%	12/187	6.4%	6/35	17.1% (6.6, 33.6)	146/152	96.1% (91.6, 98.5)	6/12	50.0% (21.1, 78.9)	146/175	83.4% (77.1, 88.6)
CD4 ≥100	21/237	8.9%	12/237	5.1%	2/21	9.5% (1.2, 30.4)	206/216	95.4% (91.7, 97.8)	2/12	16.7% (2.1, 48.4)	206/225	91.6% (87.1, 94.8)
Grade 2§ cut-off	56/424	13.2%	8/424	1.9%	3/56	5.4% (1.1, 14.9)	363/368	98.6% (96.9, 99.6)	3/8	37.5% (8.5, 75.5)	363/416	87.3% (83.7, 90.3)
Gold standard = confirmed* TB (all clinical† TB excluded) (N = 408)
Grade 1‡ cut-off	40/408	9.8%	21/408	5.1%	5/40	12.5% (4.2, 26.8)	352/368	95.7% (93.0, 97.5)	5/21	23.8% (8.2, 47.2)	352/387	91.0% (87.6, 93.6)
CD4 <100	24/176	13.6%	10/176	5.7%	4/24	16.7% (4.7, 37.4)	146/152	96.1% (91.6, 98.5)	4/10	40.0% (12.2, 73.8)	146/166	88.0% (82.0, 92.5)
CD4 ≥100	16/232	6.9%	11/232	4.7%	1/16	6.3% (0.2, 30.2)	206/216	95.4% (91.7, 97.8)	1/11	9.1% (0.2, 41.3)	206/221	93.2% (89.1, 96.2)
Grade 2§ cut-off	40/408	9.8%	8/408	2.0%	3/40	7.5% (1.6, 20.4)	363/368	98.6% (96.9, 99.6)	3/8	37.5% (8.5, 75.5)	363/400	90.8% (87.5, 93.4)

* Confirmed TB = positive on Xpert MTB/RIF or line probe assay or M. tuberculosis culture, from any sample taken within 6 months of enrolment

† Clinical TB = started TB treatment within 6 months of enrolment, in the absence of microbiological confirmation and those smear-positive in the absence of an associated culture

‡ Grade 1 positive: > = 1+

§ Grade 2 positive: > = 2+

NPV = Negative predictive value; PPV = Positive predictive value; CI = confidence interval