Project E-Shift: A Harm Reduction Intervention for Chronically Unhoused Smokers.

This pilot randomized trial tested whether switching to e-cigarettes, compared with standard nicotine replacement therapy (NRT; patch and gum), helped adults with a history of chronic homelessness stop smoking combustible cigarettes. All participants received brief cessation counseling and incentives for carbon monoxide (CO)-verified abstinence from cigarettes during the first weeks after a scheduled switch date. Participants were followed for 12 weeks after switching, with a final follow-up at 24 weeks. The study also assessed feasibility (recruitment, retention, and visit attendance) and used interviews with participants and service-agency staff to understand acceptability and how a tobacco harm reduction program could fit into existing housing and clinic services.

Inclusion Criteria: * Individuals must meet all of the following inclusion criteria in order to be eligible to participate in the study: * Provide signed and dated informed consent form * Willing to comply with all study procedures and be available for the duration of the study. * Male or female aged 21 and above. * expired CO \>6 ppm at screening * People of reproductive potential must not be pregnant nor trying to become pregnant. * Adequate literacy to complete self-administered study questionnaires, defined as a score ≥4 out of 7 on the Rapid Estimate of Adult Literacy in Medicine - Short Form (REALM-SF), corresponding to a 7th-grade reading level or higher Exclusion Criteria: * An individual who meets any of the following criteria will be excluded from participation in this study: * Anyone who has trouble understanding the consent or with significant anxiety detected during the consent process will also be excluded. * Medical condition that precludes participation * Current use of THC-containing vaping products * Pregnancy or lactation * Known allergic reactions to components of the study product(s) * Anything that would place the individual at increased risk or preclude the individual's full compliance with or completion of the study.