Table 1.

Sample characteristics by race/ethnicity.

	Non-African-American n=610	African-American n=768	p-valuea
Ever smoked a cigarette	52.46	44.13	0.01
Mean age onset (SE)	13.26(.18)	13.86 (.18)	0.017
DSM-IV nicotine dependenceb	32.81	19.82	<0.001
Mean age onset (SE)	16.91(.24)	18.51 (.39)	<0.001
Cigarettes per day when smoked mostb			0.009
≤10	54.26	72.93
11–19	18.09	10.53
19–25	18.09	10.53
≥26	9.57	6.02
Male gender	49.34	49.35	0.999
Mean age (SE)	17.33 (.14)	17.69 (.13)	0.065
Parents do not live together	46.23	71.48	<0.001
Low grades in high school	19.34	33.12	<0.001
Friends’ smoking status			0.349
No Friends Smoke	23.36	19.92
Some Friends Smoke	42.76	43.93
Most Friends Smoke	33.88	36.15
Ever Used Alcohol	59.18	49.87	0.004
Ever Intoxicated	43.35	24.58	<0.001
Ever Used Cannabis	33.33	33.86	0.859
Major Depressive Disorder	10.0	10.94	0.593
≥ 3 Conduct Disorder Symptoms	9.72	11.29	0.39
Maternal variablesc
Household income <$45,000	40.03	68.13	<0.001
Alcohol use disorder	24.43	13.99	0.001
Ever smoked ≥100 cigarettes	52.30	42.19	0.014
Education level			0.024
Less than high school	5.42	11.49
High school diploma or GED	29.39	29.63
More than high school	65.19	58.88
Paternal variablesc
Ever smoked ≥100 cigarettes	66.39	57.55	0.028
Education level			0.004
Less than high school	18.2	17.06
High school diploma or GED	37.9	51.04
More than high school	43.91	31.9

^afrom chi square (categorical variables) or t-test (continuous variables)

^bAmong ever smokers

^cMaternal report