Table 1. Distribution and percentage of smoking by characteristics of participating nurses.

Variable	N (%)	% Smoked <15	p-value*	% Smoked 15–19	p-value*
Total	68,107 (100.0)	4.8		23.0
Age started smoking
Before 15	3,287 (4.8)
Age 15–19	12,496 (18.4)
Age 20 or older	7,063 (10.4)
Never started smoking	45,261 (66.5)
Smoking status ages 15–19
No smoking	52,426 (77.0)
Smoking	15,681 (23.0)
Age at 1989			<.0001		<.0001
24–29	11,174 (16.4)	5.9		19.1
30–34	21,243 (31.2)	5.7		22.9
35–39	22,910 (33.6)	4.0		21.7
40–44	12,780 (18.8)	4.0		23.3
Race/ethnicity			<.0001		<.0001
Non-Hispanic white	63,413 (94.4)	4.9		23.4
Non-Hispanic black	801 (1.2)	3.3		16.7
Hispanic	860 (1.3)	3.3		16.9
Asian	963 (1.4)	2.2		9.7
Other	1,141 (1.7)	4.9		21.3
Parental smoking			<.0001		<.0001
None	23,888 (35.3)	2.9		16.3
Mom smoked	5,448 (8.0)	7.3		29.4
Dad smoked	19,261 (28.4)	4.4		23.5
Both parents smoked	19,160 (28.3)	7.0		29.0
Family emotional support			<.0001		<.0001
Very often	27,903 (41.0)	3.9		20.7
Often	18,783 (27.6)	4.5		22.4
Sometimes	12,468 (18.3)	5.9		25.5
Rarely	6,753 (9.9)	6.7		28.2
Never	2,098 (3.1)	7.1		27.5
Mother's educationa			0.674		0.086
Less than high school	4,161 (13.7)	4.8		20.6
High school graduate	15,150 (49.9)	4.4		22.2
Some college	7,867 (25.9)	4.4		21.8
College graduate or more	3,210 (10.6)	4.6		20.9

^*Chi-square test for difference between smoking and nonsmoking groups.

^aMeasured among the 30,562 participants whose mothers completed the Mother's Questionnaire.