Smoking is a massive public health problem; for example, it is the predominant avoidable cause of cancer, causing an estimated 45 000 cancer deaths and 110 000 hospital admissions in the UK annually.1 Smoking is also strongly associated with social disadvantage and is the leading known cause of social inequalities in health.2 Consequently, reducing smoking prevalence is an international health priority, and telephone helplines can provide smoking cessation support at low cost to many, often highly motivated, smokers. Proactive smoking cessation telephone counselling involves helpline counsellors contacting smokers according to a previously agreed schedule, whereas in reactive counselling all contact is initiated by smokers and counsellors operate in response mode. Proactive telephone counselling is effective; meta-analysis of nine trials with more than 24 000 participants gave a risk ratio for cessation after proactive counselling compared with minimal interventions or reactive counselling of 1.37 (95% CI 1.26 to 1.50).3 The …