E-cigarettes to Augment Stop Smoking In-person Support and Treatment with varenicline (E-ASSIST): a pragmatic randomised controlled trial.

Offering e-cigarettes to people quitting smoking with varenicline may help them remain abstinent from cigarettes, but the evidence is tentative because our sample size was smaller than planned - caused by COVID-19 restrictions and a manufacturing recall. This meant our effect estimates were imprecise, and additional evidence is needed to confirm that providing e-cigarettes and varenicline together helps more people remain abstinent than varenicline alone.