Table 2. Performance of three LED-based fluorescence microscopy devices in detection of tuberculosis in HIV-positive suspects in Kampala, Uganda, per patient analysis.

	ZN	Routine FM	iLED	Fraen	Lumin
Sensitivity *	32.4% (35/108) 23.7–42.0	32.4% (35/108) 23.7–42.0	44.4% (48/108) 34.9–54.3	43.5% (47/108) 34.0–53.3	40.7% (44/108) 31.3–50.6
3+	5		4	5	7
2+	7		15	13	16
1+	13		17	18	11
Scanty	10		11	11	10
No grading	0		1	0	0
Specificity *	98.7% (234/237) 96.3–99.7	99.1% (235/237) 97.0–99.9	89.5% (212/237) 84.8–93.0	87.0% (206/237) 82.0–90.9	88.1% (209/237) 83.3–92.0
PPV	92.1% (35/38) 78.6–98.3	94.6% (35/37) 81.8–99.3	65.8% (48/73) 53.7–76.5	60.2% (47/78) 48.5–71.1	61.1% (44/72) 48.9–72.3
NPV	76.2% (234/307) 71.0–80.9	76.3% (235/308) 71.2–80.9	78.0% (212/272) 72.5–82.7	77.1% (206/267) 71.6–82.0	76.6% (219/273) 71.0–81.5

^*For sensitivity calculations, the denominator is the number of patients for which the culture was positive for MTB. For specificity, the denominator shows the number of culture negative patients. None of the 3 LED FM methods was significantly different from each other. ZN, ZiehlNeelsen staining method; FM, fluorescence microscopy; PPV, positive predictive value; NPV, negative predictive value.