Mobile Chat Messaging for Preventing Smoking Relapse Amid the COVID-19 Pandemic: A Pilot Randomized Controlled Trial.

Smoking relapse is the most likely outcome of smoking cessation attempts and an undertreated problem. This pilot trial showed the feasibility and acceptability of personalized chat messaging via WhatsApp for relapse prevention in recent abstainers amid the COVID-19 pandemic. The higher carbon monoxide-validated abstinence rate in participants who received chat messaging than controls showed preliminary evidence on the effectiveness of the intervention. Fully powered trials are warranted to test the intervention.