Table 6.

Agreement Between Urine Drug Test Result and Timeline Follow-Back Data for Marijuana Use

	14-day detection window			22-day detection window			42-day detection window
Reporter	% agreement	κ	Yule's Y	% agreement	κ	Yule's Y	% agreement	κ	Yule's Y
Subject	.92	.68	.82	.92	.71	.78	.86	.61	.75
Collateral	.84	.29	.53	.84	.31	.52	.83	.31	.46

Note. n = 159 subjects with urine drug test results. Urine drug test results were coded positive/negative for marijuana use. Timeline Follow-Back data were coded yes/no for marijuana use within each detection window. Boldface values of Yule's Y (≥ .50) reflect acceptable subject–collateral agreement.