Published online by Cambridge University Press: 10 April 2013
Introduction: The ability of Swedish snus to serve as a smoking cessation aid has been documented in several observational, population surveys from Scandinavia, but randomised clinical trials provide more reliable information on efficacy. Aims: To perform a systematic review and meta-analysis of randomised clinical trials of Swedish snus as an aid to smoking cessation. Methods: Literature searches were conducted in MedLine, Cochrane Library, and Embase to identify relevant clinical trials. The primary outcome was defined as biologically confirmed smoking cessation during around six months. Meta-analyses based on primary subject data tested for effect of allocated treatment as well as selected baseline characteristics. Results: There were two relevant clinical trials, one conducted at five sites in the US (n = 250), the other at two sites in Serbia (n = 319). Based on the primary outcome, success was higher in the treated group in both Serbia (5.7% vs 1.9%) and the US (4.0% vs 1.6%). Meta-analysis estimated the relative success rate at 2.83 (95% CI 1.03–7.75), which was of borderline significance (exact p = 0.06, chi-squared p = 0.03). For smoking cessation in the last 4 weeks of each study, rates were 12.4% for snus and 6.6% for placebo (RR 1.86, 95% CI 1.09-3.18). Efficacy of snus was not clearly related to any baseline characteristic. Conclusions: Swedish snus increased quit rates similarly in US and Serbia. These results confirm and extend previous information based on observational population surveys.