Table 2.

Comparative Predictive Power 1, 2, and 3 Weeks of Thrice Weekly Screening Data for persistent MA use at EOT^*

Weeks of Screening Data	Optimal Cut-Point (Number MA Positive Screens)	AUC	SN	SP	PPV	NPV
One Week	>=1	0.743	75	64	82.8	52.9
Two Weeks	>=3	0.801	66	80	88.5	51.1
Three Weeks	>=4	0.834	72	80	89.2	55.5

^*ROC analysis assessed number of MA positive/missing urine drug screens to predict MA use at EOT. SN=sensitivity; SP=specificity; PPV=positive predictive value; NPV=negative predictive value; AUC= area under ROC curve