A systematic review and meta-analysis found that the most effective smoking cessation approach was combining medicine therapies with varenicline. These findings were published in Health Technology Assessment.

Publication databases were searched by researchers from the University of Bristol in the United Kingdom through March 2017 and updated February 2019 for randomized clinical trials of smoking cessation lasting ≥6 months. A total of 363 trials with 201,045 participants were included. For the safety review, an additional 53 observational studies comprising 8,783,5403 participants were included.