Key messages
Behavioural support can help more people to stop smoking for six months or longer, without causing unwanted effects.
Some types of support appear to work better than others. More studies are needed to identify the best ways to support people who are trying to stop smoking, and to identify the best people to support them.
Stopping smoking
The best thing people who smoke can do for their health is to stop smoking.
Most people who smoke want to stop, but many find it difficult. People who smoke may use medicines to help them stop. Behavioural support provides an alternative – or additional – way to help people stop smoking. Sometimes behavioural support can be combined with nicotine replacement or other medicines to help people stop smoking.
Types of behavioural support can include: advice and counselling on ways to make it easier to stop smoking; information about why or how to stop; or a combination. Behavioural support can be given in group sessions or one-to-one.
Why we did this Cochrane Review
We wanted to find out:
– which types of behavioural support work best to help people stop smoking;
– the best ways to give behavioural support (including the best people to give it); and
– what aspects of behavioural support help someone to stop smoking.
We also wanted to know if behavioural support can cause any unwanted effects.
What did we do?
We searched for Cochrane Reviews of behavioural support to stop smoking, to identify relevant studies of adults who smoked. We then compared the studies with each other, to find out how well the different types of behavioural support helped people to stop smoking.
Search date: we included evidence published up to July 2020.
What we found
We found 33 Cochrane Reviews, from which we identified 312 relevant studies in 250,503 adults (aged 18 to 63 years) who smoked cigarettes. The studies investigated 437 different combinations of ways to stop smoking.
Most studies were conducted in the USA or Western Europe; 115 studies took place in healthcare settings and 195 took place in the community. On average, people taking part in the studies were followed up for 10.5 months.
The studies compared the effects of behavioural support with:
– no behavioural support;
– usual or standard care;
– less-intense forms of the behavioural support; or other approaches.
We compared all treatments with each other using a mathematical method called network meta-analysis.
What are the main results of our review?
Compared with no behavioural support it was clear that some types of behavioural support increased people's chances of quitting for six months or longer, including: counselling and giving them money for successfully stopping smoking. More people stopped smoking with these types of support whether or not they were also taking medicines to help them stop smoking.
Behavioural support by text messages probably helped more people to stop smoking than no support.
Compared with no support, tailoring behavioural support to the person, or group of people, trying to stop smoking probably slightly increased how many of them stopped smoking, as did support that focused on how to stop smoking.
Increasing the intensity of the support given, such as contacting people more often or having longer sessions, modestly increased how many people stopped smoking.
We are uncertain about:
– the effects of other types of behavioural support, including hypnotherapy, exercise-based support, and entering competitions; and
– the effect of who gives the behavioural support.
Only some studies reported results for unwanted effects; in these, behavioural support did not increase the numbers of any unwanted effects.
How confident are we in our results?
We are confident that counselling and rewards of money help people to stop smoking; we do not expect that more evidence will change these results.
We are less confident in our results for other types of behavioural support, and about who gives the support and how. We found limitations with some of the studies, including how they were designed, conducted, and reported. These results are likely to change when more evidence becomes available. More studies are needed.
Behavioural support for smoking cessation can increase quit rates at six months or longer, with no evidence that support increases harms. This is the case whether or not smoking cessation pharmacotherapy is also provided, but the effect is slightly more pronounced in the absence of pharmacotherapy. Evidence of benefit is strongest for the provision of any form of counselling, and guaranteed financial incentives. Evidence suggested possible benefit but the need of further studies to evaluate: individual tailoring; delivery via text message, email, and audio recording; delivery by lay health advisor; and intervention content with motivational components and a focus on how to quit. We identified 23 economic evaluations; evidence did not consistently suggest one type of behavioural intervention for smoking cessation was more cost-effective than another. Future reviews should fully consider publication bias. Tools to investigate publication bias and to evaluate certainty in CNMA are needed.
Smoking is a leading cause of disease and death worldwide. In people who smoke, quitting smoking can reverse much of the damage. Many people use behavioural interventions to help them quit smoking; these interventions can vary substantially in their content and effectiveness.
To summarise the evidence from Cochrane Reviews that assessed the effect of behavioural interventions designed to support smoking cessation attempts and to conduct a network meta-analysis to determine how modes of delivery; person delivering the intervention; and the nature, focus, and intensity of behavioural interventions for smoking cessation influence the likelihood of achieving abstinence six months after attempting to stop smoking; and whether the effects of behavioural interventions depend upon other characteristics, including population, setting, and the provision of pharmacotherapy.
To summarise the availability and principal findings of economic evaluations of behavioural interventions for smoking cessation, in terms of comparative costs and cost-effectiveness, in the form of a brief economic commentary.
This work comprises two main elements. 1. We conducted a Cochrane Overview of reviews following standard Cochrane methods. We identified Cochrane Reviews of behavioural interventions (including all non-pharmacological interventions, e.g. counselling, exercise, hypnotherapy, self-help materials) for smoking cessation by searching the Cochrane Library in July 2020. We evaluated the methodological quality of reviews using AMSTAR 2 and synthesised data from the reviews narratively. 2. We used the included reviews to identify randomised controlled trials of behavioural interventions for smoking cessation compared with other behavioural interventions or no intervention for smoking cessation. To be included, studies had to include adult smokers and measure smoking abstinence at six months or longer. Screening, data extraction, and risk of bias assessment followed standard Cochrane methods. We synthesised data using Bayesian component network meta-analysis (CNMA), examining the effects of 38 different components compared to minimal intervention. Components included behavioural and motivational elements, intervention providers, delivery modes, nature, focus, and intensity of the behavioural intervention. We used component network meta-regression (CNMR) to evaluate the influence of population characteristics, provision of pharmacotherapy, and intervention intensity on the component effects. We evaluated certainty of the evidence using GRADE domains. We assumed an additive effect for individual components.
We included 33 Cochrane Reviews, from which 312 randomised controlled trials, representing 250,563 participants and 845 distinct study arms, met the criteria for inclusion in our component network meta-analysis. This represented 437 different combinations of components. Of the 33 reviews, confidence in review findings was high in four reviews and moderate in nine reviews, as measured by the AMSTAR 2 critical appraisal tool. The remaining 20 reviews were low or critically low due to one or more critical weaknesses, most commonly inadequate investigation or discussion (or both) of the impact of publication bias. Of note, the critical weaknesses identified did not affect the searching, screening, or data extraction elements of the review process, which have direct bearing on our CNMA. Of the included studies, 125/312 were at low risk of bias overall, 50 were at high risk of bias, and the remainder were at unclear risk. Analyses from the contributing reviews and from our CNMA showed behavioural interventions for smoking cessation can increase quit rates, but effectiveness varies on characteristics of the support provided. There was high-certainty evidence of benefit for the provision of counselling (odds ratio (OR) 1.44, 95% credibility interval (CrI) 1.22 to 1.70, 194 studies, n = 72,273) and guaranteed financial incentives (OR 1.46, 95% CrI 1.15 to 1.85, 19 studies, n = 8877). Evidence of benefit remained when removing studies at high risk of bias. These findings were consistent with pair-wise meta-analyses from contributing reviews. There was moderate-certainty evidence of benefit for interventions delivered via text message (downgraded due to unexplained statistical heterogeneity in pair-wise comparison), and for the following components where point estimates suggested benefit but CrIs incorporated no clinically significant difference: individual tailoring; intervention content including motivational components; intervention content focused on how to quit. The remaining intervention components had low-to very low-certainty evidence, with the main issues being imprecision and risk of bias. There was no evidence to suggest an increase in harms in groups receiving behavioural support for smoking cessation. Intervention effects were not changed by adjusting for population characteristics, but data were limited. Increasing intensity of behavioural support, as measured through the number of contacts, duration of each contact, and programme length, had point estimates associated with modestly increased chances of quitting, but CrIs included no difference. The effect of behavioural support for smoking cessation appeared slightly less pronounced when people were already receiving smoking cessation pharmacotherapies.