Table 1.

Definition of tobacco products user groups and specific product user groups for the present study (Hyland et al., 2017).

Definitiona
1a: Tobacco user groups
Never-tobacco user (never user) (n = 1700)	Has never used any tobacco products
Exclusive current established combustible products user (combustible products user) (n = 5767)	1. Has ever used at least one of the combustible products: cigarette, traditional cigar, cigarillo, filtered cigar, hookah, and pipe.
	2. Has used > 100 cigarettes in their entire life or fairly regularly used one or more of the following products: cigar, hookah, and pipe.
	3. Now use everyday or some days.
	4. Not current established users for any non-combustible products (answer “No” for each noncombustible products from questionnaire) (missing will not be included)
Exclusive current established non-combustible products user (noncombustible products user) (n = 860)	1. Has ever used at least one of the non-combustible products: e-cigarette, smokeless tobacco, snus pouches, and dissolvable tobacco.
	2. Has used fairly regularly.
	3. Now use everyday or some days.
	4. Not current established users for any combustible products (answer “No” for each combustible products from questionnaire) (missing will not be included).
Mixed dual user (dual user) (n = 1258)	Users who meet definition 1–3 for both combustible products user and non-combustible products user
Others (other user) (n = 1934)	Users who do not meet the above definitions for never user, combustible products user, noncombustible products user, or dual user
1b: Specific product user group
Exclusive current established cigarette user (cigarette user) (n = 3964) (subset of combustible products user)	1. Includes only cigarettes.
	2. Has ever used a cigarette
	3. Has used > 100 of the cigarettes in their entire life
	4. Now use everyday or some days
	5. Currently does not use any other products
Exclusive current established smokeless users (SLT user) (n = 509) (subset of non-combustible products user)	1. Includes moist snuff, dip, spit, chewing tobacco, loose snus and pouched snus
	2. Has ever used a smokeless product
	3. Has used fairly regularly
	4. Now use everyday or some days
	5. Currently does not use any other products
Exclusive current established e-cigarette users (e-cigarette user) (n = 280) (subset of non-combustible products user)	1. Has ever used a e-cigarette product
	2. Has used fairly regularly
	3. Now use everyday or some days
	4. Currently does not use any other products
Never-tobacco user (never user) (n = 1700)	Has never used any tobacco products

^aTo belong to a given user group category, a person must meet all conditions included under the definition ofthe category.