Table 3.

Performance of different thresholds of the score of the prediction tool for virologic failure

Score*	Sensitivity (%)	Specificity (%)	n	PPV (%)	NPV (%)	AUROC	% need VL test	VF missed (%)
≥ 1	100.0	3.7	920	9.7	100	0.7694	96.1	0/90
≥ 2	90.0	29.7	687	11.8	96.6	0.7651	71.8	9/90 (10%)
≥ 3	75.6	69.7	329	20.7	96.5	0.7164	34.8	22/90 (24%)
≥ 4	38.9	93.0	95	36.8	93.6	0.6681	9.9	55/90 (61%)

^*Variables included in tool: age <38 years, ART duration >2.5 years, ART adherence <95%, hemoglobin <13 g/dL, and CD4 <200 cells/µL

PPV – positive predictive value; NPV – negative predictive value; AUROC – area under receiver operator curve; VL – viral load