Table 2.

Initial Layout of Combined Data Set

Data set	Add Health items	CDP items	GSMS items	“Gold standard” (AUDIT) items	Demographic variables (transformed/recoded)
Add Health	X	--	--	--	X
CDP	--	X	--	--	X
GSMS	--	--	X	--	X
KN	X	X	X	X	X

Note. Add Health = National Longitudinal Study of Adolescent Health; CDP = Child Development Project; GSMS = Great Smoky Mountains Study of Youth; KN = Knowledge Networks calibration study. Available data are marked with an ‘X’; missing data are denoted with ‘—’.