. Author manuscript; available in PMC: 2006 Jul 6.

Published in final edited form as: Psychol Addict Behav. 2005 Dec;19(4):404–413. doi: 10.1037/0893-164X.19.4.404

Table 2.

Concordance Between Urine Assay Result and Dichotomized Adolescent Measures

Concordance relation	Baseline (κ)	6 months (κ)	18 months (κ)
Marijuana on TLFB, ADAD, and urine	0.32^**	0.52^**	0.58^**
Cocaine on TLFB, ADAD, and urine	0.38^**	0.49^**	0.56^**

Note. TLFB = Timeline Followback; ADAD = Adolescent Drug Abuse Diagnosis Scale.

^**

p < .01.