Table 1. Percent baseline characteristics of adolescent smokers by smoking frequency.

Baseline variable		Infrequent Smokersa N=627	Occasional Smokersb N=420	Regular Smokersc N=790
Demographic Variables
Gender
	Female	50.6%	44.0%	50.0%
	Male	49.4%	56.0%	50.0%
	p-valued for gender:			0.94
Ethnicity/Race
	White	75.1%	75.5%	76.2%
	American Indian/Alaska Native	2.2%	2.4%	3.3%
	Asian	3.7%	6.9%	3.5%
	Black or African American	1.8%	2.6%	1.9%
	Hispanic ethnicity	5.3 %	3.3%	3.0%
	Native Hawaiian or Other Pacific Islander	1.3%	1.9%	0.9%
	Other Race	1.4%	1.2%	0.8%
	Multiple Races/Ethnicities	7.2%	5.2%	7.8 %
	p-valued for % White			0.50
Age at baseline data collection
	<16 years old	0.0%	0.0%	0.1%
	16 years old	31.6%	32.1%	28.6%
	17 years old	63.6%	61.0%	63.4%
	> 17 years old	4.8%	6.9%	7.8 %
	p-valued for >17 years old:			0.02
Smoking history and current smoking
Age at first cigarette
	≤ 8 years old	4.0%	7.4%	11.8%
	9-12 years old	24.6%	27.4%	35.7%
	13-16 years old	55.7%	56.4%	48.2%
	> 16 years old	15.3%	8.3%	3.7%
	p-valued for % first use before age 13:			<0.01
Number of cigarettes smoked in lifetime
	≤ 1	6.2%	0.5%	1.0%
	2-100	72.6%	44.8%	6.5%
	101-400	10.7%	33.6 %	19.6%
	> 400	9.1%	19.8%	70.4%
	p-valued for % > 100 cigarettes:			<0.01
Current use of other tobacco productse
	Not at all	44.8%	39.5%	36.5%
	Less than monthly	27.8%	19.5%	24.6%
	At least monthly, but not daily	19.9%	28.8%	16.7%
	Daily	4.9%	9.0%	18.7%
	p-valued for % Not at all:			<0.01

^aInfrequent smokers defined as having smoked on 1-4 days in the last month.

^bOccasional smokers defined as having smoked on 5-19 days in the last month.

^cRegular smokers defined as having smoked on 20 or more days in the last month.

^dp-value for trend: H₀: Same (true) percentage for all 3 smoking frequency categories.

^eCurrent use of other tobacco products: frequency of use of chewing tobacco/snuff, cigars, bidis or clove cigarettes, or pipe tobacco.