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

This two-arm, parallel-group, open-label pilot randomized trial compared e-cigarette (EC) switching with nicotine replacement therapy (NRT) among adults who smoke cigarettes and have a history of chronic homelessness, recruited through Pathways to Housing PA and affiliated clinic services in Philadelphia \[confirm sites\]. Both arms received standard cessation counseling and financial incentives contingent on carbon monoxide (CO)-verified abstinence from combustible cigarettes during the early post-switch period. Because both arms received incentives, the trial compares EC with NRT in the presence of incentives and does not isolate the effect of incentives. After consent and baseline assessment, participants were randomized 1:1 to EC plus financial incentives (EC+FI) or NRT plus financial incentives (NRT+FI). EC+FI participants received a pod-based device and a one-week practice supply of pods before a scheduled switch date one week after baseline. NRT+FI participants received nicotine patch and gum. At consent, all participants were counseled on e-cigarette or vaping use-associated lung injury (EVALI) and instructed not to use THC-containing, non-study, or modified vaping products. Assessments occurred on the switch date, weekly at 1 through 4 weeks post-switch, and at 8, 10, and 12 weeks post-switch, with a final self-report follow-up at 24 weeks post-switch. Visits included self-report questionnaires on tobacco and nicotine product use, withdrawal symptoms, respiratory symptoms, and mental health, and expired CO measurement (through week 12). Abstinence-contingent incentives were available from the switch date through week 4 only; later visits were unincentivized to assess maintenance after incentive withdrawal. Study product was resupplied at each visit through week 8, with EC pods dosed to pre-switch cigarettes per day and used pods returned before resupply, and was then discontinued to assess unsupported continuation. A subsample of participants and partner-agency staff completed semi-structured interviews on intervention acceptability and on integrating tobacco harm reduction into existing service workflows.