| OR (95% CI) | Abstinence rate % | |
| Placebo | 1.0 | 13.8 |
| Monotherapies | ||
| Varenicline | 3.1 (2.5–3.8) | 33.2 |
| High-dose nicotine patch | 2.3 (1.7–3.0) | 26.5 |
| Nicotine gum (>14 weeks) | 2.2 (1.5–3.2) | 26.1 |
| Bupropion SR | 2.0 (1.8–2.2) | 24.2 |
| Combination therapies | ||
| Patch plus ad lib NRT | 3.6 (2.5–5.2) | 36.5 |
| Patch plus bupropion SR | 2.5 (1.9–3.4) | 28.9 |
| Patch plus inhaler | 2.2 (1.3–3.6) | 25.8 |
Meta-analysis of data from placebo, controlled trials in smoking cessation reporting 1-yr quit rates with smoking cessation drugs used for 3 months in combination with counselling. The comparator is the placebo arm without drugs but with counselling. NRT: nicotine replacement therapy. Modified from [8].