Table 2.

Index participant eligibility and rationale for index participants and family members in all three study phases.

Study Inclusion Criteria	Rationale
Index participants
ANAI person (based on self-reported race/ethnicity) residing in Alaska. Both men and women will be included.	An estimated 27,712 ANAI adults using tobacco (i.e., 37% of total ANAI persons ages 21 and older [1,38]) are potentially eligible.
Aged ≥21 years	Legal smoking age in Alaska is 21 years
Self-report cigarette smoking in the past 7 days and (phases 2 and 3 only) biochemically verified with breath expired air CO ≥ 4 ppm and saliva cotinine ≥30 n/ml (positive Alere™ iScreen result).	Incentives are offered for smoking abstinence with the intervention. Thus, it is important to verify the individual currently smokes at study enrollment.
Smoked ≥3 cigarettes per day (cpd) over the past 3 months.	Includes “light” smoking as prior studies found that ANAI people reporting “light” smoking (7.8 cpd) have cotinine concentrations equivalent to White “heavy” smoking (15 cpd), due to nicotine metabolism differences [39].
Phases 2 and 3 only: Current smoking status will be biochemically verified.
Cigarettes are the main tobacco product used if other nicotine/tobacco products are used.	Cigarette smoking paired with ST use is prevalent in some Alaska rural regions [1]; thus, results are more generalizable if other tobacco use is allowed.
Considering or willing to make a quit attempt.	Study promotes quitting smoking.
No use of cessation pharmacotherapy or stop smoking program in the past 3 months.	Study promotes quitting smoking.
Has an adult family member who would be supportive of their efforts to quit smoking and (in phases 2 and 3) will enroll in the study.	Study focuses on ANAI families.
	Phases 2 and 3 enroll dyads and thus requires a family member to also enroll.
No other index participant from the same household has enrolled.	Facilitates obtaining different perspectives in phase 1. Mitigates potential lack of independence of households/social networks in phases 2 and 3. Reduces the risk for cross-condition contamination in phase 3.
Phases 2 and 3 only: Owns or has access to a mobile phone or tablet with internet and text messaging capabilities (or will be loaned an iPad with data plan remuneration for the study duration).	Facilitates completion of the six smoking check-ins and receiving text messages during the treatment phase.
Phase 3 only: Has not participated in a prior study phase.	Mitigates potential lack of independence of households/social networks and reduces the risk for cross-condition contamination.
Provides informed consent.	Verbal consent in phase 1, written consent in phases 2 and 3.
Family member participants
Defined as family by the index participant.	Initial community feedback suggested a broad definition of family member and includes household or non-household members, and individuals who smoke or do not smoke.
Both men and women and all races will be included.
Aged ≥21 years.	Enrolled family members may also smoke. The legal smoking age in Alaska is 21 years.
Provides informed consent.	Verbal consent in phase 1, written consent in phases 2 and 3.
Enrolled to support only one index participant.	Facilitates obtaining different perspectives in phase 1. Mitigates potential lack of independence of households/social networks in phases 2 and 3. Reduces the risk for cross-condition contamination in phase 3.
Phases 2 and 3 only: Owns or has access to a mobile phone or tablet with internet and text messaging capabilities (or will be loaned an iPad with data plan remuneration for the study duration).	Facilitates receiving text messages during the treatment phase.
Phase 3 only: Has not participated in a prior study phase	Mitigates potential lack of independence of households/social networks and reduces the risk for cross-condition contamination.

Table note: ANAI = Alaska Native or American Indian, CO = carbon monoxide, ST = smokeless tobacco.