Table 2.

Estimates of unadjusted relative risk for becoming an illegal drug user or legal drug user by young adulthood among youths from an urban public school system, Mid-Atlantic region, United States: 1985–2002^a

		Cocaine (n = 102 users)			Cannabis (n = 1,102 users)			Tobacco (n = 1,049 users)			Alcohol (n = 1,617 users)
Covariate	RR	95% CI	p-value	RR	95% CI	p-value	RR	95% CI	p-value	RR	95% CI	p-value
Sex
Female	1.0			1.0			1.0			1.0
Male	1.8	1.2, 2.7	0.006	2.8	2.3, 3.5	<0.001	2.0	1.7, 2.5	<0.001	1.0	0.6, 1.6	0.99
Disadvantaged Minority
Minority	1.0			1.0			1.0			1.0
Nonminority	18.1	10.4, 31.7	<0.001	1.3	1.1, 1.7	0.014	2.3	1.8, 2.9	<0.001	2.1	1.1, 3.9	0.02
Subsidized/free lunch in 1st grade
No	1.0			1.0			1.0			1.0
Yes	0.3	0.2, 0.4	<0.001	0.9	0.7, 1.1	0.161	0.7	0.6, 0.9	0.002	0.6	0.4, 0.9	0.04
First-grade cohort
1985	1.0			1.0			1.0			1.0
1986	1.1	0.7, 1.6	0.76	1.0	0.8, 1.2	0.879	1.0	0.8, 1.2	0.84	1.5	0.9, 2.4	0.11
Childhood misbehavior ratingb	1.3	1.1, 1.6	0.012	1.6	1.4, 1.8	<0.001	1.3	1.1, 1.4	<0.001	1.1	0.9, 1.4	0.41

^aData were obtained from 1,692 participants; see footnote in Table 1. These estimates of relative risk are from the generalized linear model (logit link) with a generalized estimating equations approach to address interdependencies of the four binary responses (cumulative occurrence of drug-taking by young adulthood).

^bChildhood misbehavior was rated in the fall of first grade according to the Teacher Observation of Classroom Adaptation-Revised (Werthamer-Larson, et al. 1991). Ratings of misbehavior were missing because students transferred to other schools or due to circumstances in which the teacher could not complete the ratings. Relative risk estimates are for every increase of one standard deviation above the mean of the standardized scale.