Conventional advice to smokers who want to quit is to stop abruptly in a single step.       

Although there is some evidence to suggest a modest benefit in quit rates with abrupt cessation compared with gradual reduction, study data have not been conclusive and there have been no specific trials to provide a direct comparison between the two methods.

To address this the authors of this study conducted a large trial to test whether or not an initial gradual reduction in smoking results in non-inferior quit rates compared with abrupt cessation.¹

The investigators recruited 697 adult smokers across 31 volunteer general practices in England. All recruited participants were nicotine dependent and using more than 15 cigarettes a day or equivalent or had an end-expiratory carbon monoxide concentration of at least 15 ppm. Smokers with substance misuse and/or physical and mental health problems were excluded from the trial only if their problems were severe. Of the total participants,355 were randomly assigned to the abrupt cessation group and 342 to the gradual reduction group. Median age was 49 years in both groups and around 50% were women.

All participants were asked to set a quit day two weeks after enrollment. The gradual cessation group were provided with a two-week structured smoking reduction plan prior to the planned quit day over two nurse-led appointments. They aimed to reduce smoking to half the baseline level by the end of the first week and to a quarter by the end of the second. They were also given a choice of short-acting nicotine replacement therapy (NRT), most chose gum, lozenges or sublingual tablets, and nicotine patches before the quit day.

Participants in the abrupt cessation group were advised not to reduce smoking before the quit day, and received nicotine patches alone.

To balance support time during the initial two-week period the abrupt cessation group were helped to plan strategies to avoid relapse after quitting.

Both groups received behavioural support, nicotine patches, and short-acting NRT after the quit day.

The study’s primary outcome was validated abstinence four weeks after the quit day, and the secondary outcome prolonged abstinence at six months. Follow-up clinic sessions included assessment of the level of smoking, severity of nicotine withdrawal symptoms and measurement of salivary cotinine and exhaled carbon monoxide concentration.

The primary outcome of four weeks’ abstinence occurred in 39.2% (95% CI: 34.0-44.4%) of the gradual cessation group and 49.0% (95% CI: 43.8-54.2%) of the abrupt cessation group. Achieving abstinence was significantly less likely in the gradual than abrupt cessation group, adjusted RR 0.80 (95% CI: 0.66-0.93).

There were no differences between the groups in withdrawal symptoms and urge intensity scores over the four weeks, both reducing over time. Medication was tolerated well and there was good adherence to behavioural instructions and prequit NRT.

The risk estimates for the secondary outcome, six months’ prolonged abstinence, also indicated that abrupt quitting was more effective. At six months, 15.5% (95% CI: 12.0-19.7%) of participants in the gradual cessation group were still abstaining from smoking compared with 22.0% (95% CI: 18.0-26.6%) in the abrupt cessation group; RR 0.71 (95% CI: 0.46-0.91).

When questioned at baseline before randomisation, 32% of participants said that if given a choice they would have chosen abrupt cessation, 51% gradual cessation and 17% expressed no preference. Among those whose preference would have been gradual cessation but were allocated to abrupt cessation, abstinence at four weeks was 42.0% compared with 34.6% in those randomised to gradual cessation, although the difference was not significant.

The authors found clear evidence that quitting abruptly was superior in both the short- and longer-term over gradual cessation, and conclude that in clinical practice patients should be encouraged to stop smoking abruptly and not gradually.

‘Abrupt quitting is the more effective method — even in persons who prefer not to,’ they state.