Does more support increase success amongst people using medications to quit smoking?

Background

Medications (including all types of nicotine replacement therapy, bupropion and varenicline) have been shown to help people quit smoking, and people who want help to quit will often be offered medication (pharmacotherapy). Behavioural support also helps people to quit. Behavioural support may include brief advice or more intensive counselling, and may be provided face-to-face on a one-to-one basis or in groups, or by telephone, including 'quitlines'. It has been unclear how much additional benefit is gained from adding support, or providing more intensive support for people who are using medication to help them quit.

Study characteristics

We looked for studies that included smokers and provided or offered medication to everyone. People in the studies were then randomly split into groups which received different amounts or kinds of behavioural support. To assess whether the support given helped people to quit, the studies had to count the number of people not smoking after six months or more. We did not look at studies that only included pregnant women.

Key results

We searched for studies in June 2018. We included 83 studies, with almost 30,000 people. Most studies included people who wanted to quit smoking, but a small number of studies offered support to people who were not trying to quit. Combining results from 65 trials suggested that increasing the amount of behavioural support for people using a stop-smoking medication increases the chances of quitting smoking. About 17% of people in the groups receiving less or no support quit smoking, compared to about 20% in the groups receiving more support. Providing some support via personal contact, face-to-face or telephone, is helpful. Few studies compared different types of support. More research is needed to find out if some types of behavioural support help more people using medication to quit smoking.

Quality of the evidence

We judged the overall quality of evidence to be high, meaning further research is very unlikely to change our results. This review has been updated twice and both times the findings remained very similar, even though many new studies were added.

Authors' conclusions: 

There is high-certainty evidence that providing behavioural support in person or via telephone for people using pharmacotherapy to stop smoking increases quit rates. Increasing the amount of behavioural support is likely to increase the chance of success by about 10% to 20%, based on a pooled estimate from 65 trials. Subgroup analysis suggests that the incremental benefit from more support is similar over a range of levels of baseline support. More research is needed to assess the effectiveness of specific components that comprise behavioural support.

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Background: 

Pharmacotherapies for smoking cessation increase the likelihood of achieving abstinence in a quit attempt. It is plausible that providing support, or, if support is offered, offering more intensive support or support including particular components may increase abstinence further.

Objectives: 

To evaluate the effect of adding or increasing the intensity of behavioural support for people using smoking cessation medications, and to assess whether there are different effects depending on the type of pharmacotherapy, or the amount of support in each condition. We also looked at studies which directly compare behavioural interventions matched for contact time, where pharmacotherapy is provided to both groups (e.g. tests of different components or approaches to behavioural support as an adjunct to pharmacotherapy).

Search strategy: 

We searched the Cochrane Tobacco Addiction Group Specialised Register, clinicaltrials.gov, and the ICTRP in June 2018 for records with any mention of pharmacotherapy, including any type of nicotine replacement therapy (NRT), bupropion, nortriptyline or varenicline, that evaluated the addition of personal support or compared two or more intensities of behavioural support.

Selection criteria: 

Randomised or quasi-randomised controlled trials in which all participants received pharmacotherapy for smoking cessation and conditions differed by the amount or type of behavioural support. The intervention condition had to involve person-to-person contact (defined as face-to-face or telephone). The control condition could receive less intensive personal contact, a different type of personal contact, written information, or no behavioural support at all. We excluded trials recruiting only pregnant women and trials which did not set out to assess smoking cessation at six months or longer.

Data collection and analysis: 

For this update, screening and data extraction followed standard Cochrane methods. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically-validated rates, if available. We calculated the risk ratio (RR) and 95% confidence interval (CI) for each study. Where appropriate, we performed meta-analysis using a random-effects model.

Main results: 

Eighty-three studies, 36 of which were new to this update, met the inclusion criteria, representing 29,536 participants. Overall, we judged 16 studies to be at low risk of bias and 21 studies to be at high risk of bias. All other studies were judged to be at unclear risk of bias. Results were not sensitive to the exclusion of studies at high risk of bias. We pooled all studies comparing more versus less support in the main analysis. Findings demonstrated a benefit of behavioural support in addition to pharmacotherapy. When all studies of additional behavioural therapy were pooled, there was evidence of a statistically significant benefit from additional support (RR 1.15, 95% CI 1.08 to 1.22, I² = 8%, 65 studies, n = 23,331) for abstinence at longest follow-up, and this effect was not different when we compared subgroups by type of pharmacotherapy or intensity of contact. This effect was similar in the subgroup of eight studies in which the control group received no behavioural support (RR 1.20, 95% CI 1.02 to 1.43, I² = 20%, n = 4,018). Seventeen studies compared interventions matched for contact time but that differed in terms of the behavioural components or approaches employed. Of the 15 comparisons, all had small numbers of participants and events. Only one detected a statistically significant effect, favouring a health education approach (which the authors described as standard counselling containing information and advice) over motivational interviewing approach (RR 0.56, 95% CI 0.33 to 0.94, n = 378).

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