Sixty RCTs and quasi-RCTs were included. Numbers of participants and quality assessment results were reported in full, but no overall summary was reported.
Compared with no intervention or generic self-help material, interventions using electronic aids significantly increased the likelihood of achieving prolonged abstinence or point prevalence abstinence from smoking, measured at the longest follow-up. Pooled relative risks were 1.32 (95% CI 1.21 to 1.45) for prolonged abstinence and 1.14 (95% CI 1.07 to 1.22) for point prevalence abstinence at follow-up. There was no substantial heterogeneity in these analyses.
There were no substantial differences in effect size between aid to cessation and cessation induction studies.
The mixed-treatment comparison showed a small but statistically significant positive intervention effect on time to relapse (mean HR 0.87, 95% CrI 0.83 to 0.92).
Extensive further results were reported.