Table II.

Sensitivity and Specificity at Adherence Cut-Points

Parent-reported adherence	EM adherencea
	Adherent	Non- adherent	Total n	Sensitivity %	Specificity %	PPV %	NPV %	Accuracy %
50% cut-point
Adherent	39	1	40	100.0	–	97.5	0.0	97.5
Non-adherent	0	0	0
Total	39	1	40
60% cut-point
Adherent	37	3	40	100.0	–	92.5	0.0	92.5
Non-adherent	0	0	0
Total	37	3	40
70% cut-point
Adherent	34	6	40	100.0	–	85.0	0.0	85.0
Non-adherent	0	0	0
Total	34	6	40
80% cut-point
Adherent	26	8	34	96.3	38.5	76.5	83.3	77.5
Non-adherent	1	5	6
Total	27	13	40
85% cut-point
Adherent	25	9	34	96.2	35.7	73.5	83.3	75.0
Non-adherent	1	5	6
Total	26	14	40
90% cut-point
Adherent	20	11	31	95.2	42.1	64.5	88.9	70.0
Non-adherent	1	8	9
Total	21	19	40

Note. PPV = positive predictive value; NPV = negative predictive value; – = could not be calculated due to category frequencies.

^aElectronic monitoring (EM) adherence used as the reference standard.