Table 1.

Tobacco user group definitions.

Tobacco User Group	Definition
Every Day Established Combustible Product User (Smokers; n = 3156)	For at least one combustible product: Has ever used the product If cigarettes, has smoked 100 cigarettes in lifetime. If other product, has used the product fairly regularly Currently uses every day Does not now use any smokeless products (answer “No” for each smokeless product questions from questionnaire) or e-cigarettes AND are not currently using any nicotine replacement therapy (NRT).
Every Day Established E-cigarette User (ENDS Users; n = 149)	Respondents who have used e-cigarettes every day AND are not current established or experimental users of any combustible product or smokeless tobacco, AND are not currently using any nicotine replacement therapy (NRT).
Every Day Established Smokeless Product User (Smokeless Users; n = 353)	For at least one smokeless tobacco product: Has ever used the product Has used the product fairly regularly Currently uses every day Does not now use any combustible products nor e-cigarettes AND are not currently using any nicotine replacement therapy (NRT).
Never Users (n = 1563)	Has never used any tobacco product.