Efficacy of smartphone applications to help cancer patients quit smoking: Protocol of the Quit2Heal randomized controlled trial

Cigarette smoking is highly prevalent among cancer patients in the United States (US), with up to half of cancer patients smoking at the time of their initial cancer diagnosis. However, evidence-based cessation programs are rarely implemented in oncology care, and smoking is not consistently treated in cancer treatment settings. Consequently, there is an urgent need for accessible and efficacious cessation treatments that are uniquely tailored to the needs of cancer patients. Here we describe the design and implementation of a randomized controlled trial (RCT) testing the efficacy of a smartphone app (Quit2Heal) versus a US Clinical Practice Guidelines-based app (QuitGuide) for smoking cessation among a planned sample of 422 cancer patients. Qui-t2Heal is designed to address cancer-related shame, stigma, depression, anxiety, and knowledge about the consequences of smoking/quitting. Quit2Heal is based on the principles of Acceptance and Commitment Ther-apy, a behavioral therapy that teaches skills for accepting cravings to smoke without smoking, values-driven motivation to quit, and preventing relapse. The primary aim of the RCT is to determine whether Quit2Heal has significantly higher self-reported 30-day point prevalence abstinence at 12 months relative to QuitGuide. The trial will also determine whether Quit2Heal's effect on cessation is (1) mediated by improvements in cancer -related shame, stigma, depression, anxiety, and knowledge about the consequences of smoking/quitting; and (2) moderated by baseline factors (e.g., cancer type, stage, time since diagnosis). If successful, Quit2Heal will offer a more efficacious, broadly scalable smoking cessation treatment that could be implemented alongside existing oncology care, thereby improving cancer outcomes.