Table 1.

Eligibility criteria

Inclusion criteria	Exclusion criteria
≥21 years old	Regular use of other tobacco products
Smoked ≥5 cigarettes per day on ≥25 out of the past 30 days	Use of e-cigarettes ≥4 out of the past 30 days
Smoked cigarettes for ≥6 months	Current enrollment in cessation program or trial
aeCO ≥6 ppm at screening	Use of nicotine replacement therapy or smoking cessation medication in the past 30 days
Systolic blood pressure of <160	Hospitalization for a psychiatric condition in the past 30 days
Diastolic blood pressure of <105	Experience of a heart-related event in the past 30 days
Fluent in English or Spanish	Living with another person enrolled in the study
Willing to switch from combustible cigarettes to e-cigarettes for 6 weeks	Plans to move from Kansas City or San Diego during the trial
Access to a phone	Being pregnant, breastfeeding, or planning to become pregnant
Reliable transportation	Unstable mental or health status
Identified as Hispanic/Latinx (San Diego) or Black/AA (Kansas City)

Note. ^aeCO = exhaled carbon monoxide; AA = African American.