| Study/country | Population (follow-up rate) | Intervention(s) | Control | Criteria for cessation | ||||
| Borland et al, 20017 Australia | 998 callers to Victorian quitline (66%) | Additional calls, 2 or more according to need, average 2.8 | Motivational counselling at initial call, self help materials | Quit at 12 months (sustained for 9 months) | ||||
| Borland et al, 20038 Australia | 1051* callers to Victorian quitline (76%) | Additional calls usually over 2–3 weeks, average 4.8 | Quit pack and 3 mailings of tailored letters, possibility of brief counselling at initial call | Quit at 12 months (sustained for 9 months) | ||||
| Gilbert et al, 20069 United Kingdom | 1457 UK quitline callers (63%) | Up to 5 calls over 4 weeks. 26% received none, 42% received ⩾4 | Counselling at initial call, self help materials | Quit at 12 months (sustained for 6 months) | ||||
| Hollis et al, 200510 United States | 4614 Oregon quitline users (69%) | Factorial trial of free NRT and 3 levels of counselling(1) Moderate counselling; 30–40 minutes motivational interview, brief 2nd call, tailored self help.(2) As (1) plus offer of 4 further calls | Brief 15-minute telephone counselling, self help materials and referral information, +/− NRT | Quit at 12 months (for >30 days) | ||||
| Rabius et al, 200411 United States | 3522 quitline callers (∼66% at 3 months) | 5 calls over 2 weeks (Stanford model) | Self help materials | Quit at 6 months (for 3 months) | ||||
| Smith et al, 200413 Canada | 632 quitline callers (73% print only, 62% counselling at 12 months) | (1) 50-minute initial call then 2 5–10-minute calls at 2 and 7 days | Self help materials | Quit at 12 months (sustained) | ||||
| (2) As (1) plus 4 further calls at 14, 21, 35 and 49 days (factorial with self help variants) | ||||||||
| Zhu et al, 199614 United States | 3030 California quitline callers (86%) | (1) single 50-minute call pre-quit date | Self help materials | Quit at 13 months (for 12 months) | ||||
| (2) As (1) plus up to 5 further calls over 1 month | ||||||||
| Zhu et al, 200215 United States | 3282 California quitline callers seeking counselling (71%) | Up to 7 calls over 3 months, First session pre-quit (72% received at least 1 call average 3 sessions | Self help materials. Telephone counselling also provided if requested (32% received) | Quit at 13 months (for 12 months) | ||||
| Rabius et al, 2006†12 21 | 6322 American Cancer Society quitline callers (52%) | 3×2 factorial trial of session length and use of boosters | Self help materials only | Quit at 6 months | ||||
| Zhu et al 2004†16 | 1101 pregnant women calling California smokers’ helpline | Up to 7 counselling calls (1 pre-quit, up to 6 follow-up). | Quit kit including American Cancer Society booklet for pregnant smokers | Quit for ⩾30 days at 3rd trimester evaluation |
NRT, nicotine replacement therapy.
*In relevant arms.
†Not included in meta-analysis.