Care to Quit: a stepped wedge cluster randomised controlled trial to implement best practice smoking cessation care in cancer centres

Background Cigarette smoking in people with cancer is associated with negative treatment-related outcomes including increased treatment toxicity and complications, medication side effects, decreased performance status and morbidity. Evidence-based smoking cessation care is not routinely provided to patients with cancer. The purpose of this study is to determine the effectiveness of a smoking cessation implementation intervention on abstinence from smoking in people diagnosed with cancer. Methods: A stepped wedge cluster randomised design will be used. All sites begin in the control condition providing treatment as usual. In a randomly generated order, sites will move to the intervention condition. Based on the Theoretical Domains Framework, implementation of Care to Quit will include (i) building the capability and motivation of a critical mass of key clinical staff and identifying champions; and (ii) identifying and implementing cessation care models/pathways. Two thousand one hundred sixty patients with cancer (diagnosed in the prior six months), aged 18+, who report recent combustible tobacco use (past 90 days or in the 30 days prior to cancer diagnosis) and are accessing anti-cancer therapy, will be recruited at nine sites. Assessments will be conducted at baseline and 7-month follow-up. The primary outcome will be 6-month abstinence from smoking. Secondary outcomes include biochemical verification of abstinence from smoking, duration of quit attempts, tobacco consumption, nicotine dependence, provision and receipt of smoking cessation care, mental health and quality of life and cost effectiveness of the intervention. Discussion: This study will implement best practice smoking cessation care in cancer centres and has the potential for wide dissemination.