Table 3. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) (95% confidence intervals) of dried blood spot (DBS) and dried plasma spot (DPS) compared with paired plasma specimen VL, patient support centers, Nyanza, Kenya.

(November 2012 to February 2013).

		Plasma VL
CAP/CTM	DBS VL	Detectable	Undetectable	Total	Sensitivity = 100.0 (97.6–100.0) Specificity = 4.0 (0.5–13.7) PPV = 75.8 (69.2–81.6) NPV = 100.0 (15.8–100.0)
	Detectable	150	48	198
	Undetectable	0	2	2
	Total	150	50	200
Abbott	DBS VL	Detectable	Undetectable	Total	Sensitivity = 93.9 (88.8–97.2) Specificity = 88.0 (82.2–92.4) PPV = 100.0 (97.4–100.0) NPV = 85.3 (73.8–93.0)
	Detectable	137	0	137
	Undetectable	11	52	63
	Total	148	52	200
CAP/CTM	DPS VL	Detectable	Undetectable	Total	Sensitivity = 94.7 (89.8–97.7) Specificity = 94.0 (83.5–98.8) PPV = 97.9 (94.1–99.6)
	Detectable	142	3	145
	Undetectable	8	47	55
	Total	150	50	200
Abbott	DPS VL	Detectable	Undetectable	Total	Sensitivity = 97.3 (93.2–99.2) Specificity = 98.1 (89.7–100.0) PPV = 99.3 (96.2–100.0) NPV = 92.7 (82.4–98.0)
	Detectable	142	1	143
	Undetectable	6	51	57
	Total	148	52	200

DBS viral load cut off of 400copies/mL and 550 copies/mL were used for CAP/CTM and Abbott respectively