BACKGROUND: Tobacco smoking is the leading cause of preventable disease and death in Canada. The objective of this Canadian Task Force on Preventive Health Care guideline is to provide primary care providers with evidence-based recommendations on smoking cessation options for nonpregnant adults aged 18 years or older who smoke tobacco cigarettes.

METHODS: We commissioned systematic reviews on evidence of benefits and harms of smoking cessation interventions in adults, comprising an overview of Cochrane reviews on behavioural interventions, pharmacotherapy, and other interventions, and a systematic review on electronic cigarettes (e-cigarettes). We used the Grading of Recommendations, Assessment, Development and Evaluation approach to determine the certainty of evidence for each outcome and strength of recommendations; adhered to the Guidelines International Network (GIN) principles for managing competing interests; and followed Appraisal of Guidelines for Research and Evaluation (AGREE II), GIN, and Guidance for Reporting Involvement of Patients and the Public reporting guidance.

RECOMMENDATIONS: As part of good clinical care, providers are expected to be knowledgeable about their patients' smoking status. We recommend that all people who smoke tobacco cigarettes be encouraged to stop and offered 1 or more recommended smoking cessation interventions (strong recommendation, high certainty). We provide a menu of recommended interventions that include behavioural, pharmacotherapy, and combined interventions. Shared decision-making should be used to determine patients' cessation preferences. We suggest against using e-cigarettes for smoking cessation for most people because of uncertainty about unapproved products, long-term harms, and public health impacts, but recognize that this may be considered for people who have unsuccessfully attempted other interventions or express a strong preference.

INTERPRETATION: This guideline provides a menu of evidence-based options to support smoking cessation. The menu approach places a strong emphasis on using shared decision-making to help guide people who smoke to options that are accessible to them and fit their values and preferences.