Part Five
Smoking Cessation
Smoking Cessation Interventions
5.1 Many approaches have been developed to help people stop smoking. In order to arrive at a clearer idea of their effectiveness, the Committee received the results of a systematic review of the efficacy of smoking cessation interventions, based on the analysis of data from 188 randomised controlled trials. The review has since been published in the Archives of Internal Medicine.83 The report concluded that routine advice by family doctors to give up smoking is useful, and that nicotine replacement therapy in nicotine dependent people is effective.
5.2 Other interventions include psychological approaches such as behavioural techniques. Pharmacological treatments currently available in the UK, other than nicotine replacement therapy, are not effective. (See also paras. 5.11 and 9.3)
Guidelines
5.3 The Committee noted a publication by the United States Agency for Health Care Policy and Research (AHCPR) entitled Smoking Cessation Clinical Practice Guideline (1996).84 The Guideline, which was based on a careful analysis of scientific evidence, concluded that a number of effective interventions to help people stop smoking are available and should be incorporated into the routine practice of medicine. Both brief and more intensive counselling and support are effective and have their place. The Committee noted that the Health Education Authority is developing similar guidelines for the National Health Service.
5.4 The Committee agreed that standardisation of the timing and nature of advice provided by doctors and midwives to pregnant smokers (see para. 1.17) should be promoted and the effectiveness of such measures should be evaluated.
Advice and Encouragement
5.5 The results of the review83 show that simple, brief, unsolicited advice from a general practitioner (GP) is effective in increasing rates of smoking cessation. An estimated 2% of smokers, given advice by their GP, stopped smoking and did not relapse up to one year as a direct consequence of such advice. The Cochrane Collaboration review confirmed the effectiveness of GP smoking cessation advice.85 This form of intervention is extremely cost effective.
5.6 Additional interventions, supplementary to simple advice, such as follow up letters and visits, show mixed results.
5.7 The contribution made by health promotion clinics, which are usually run by nurses, is unknown. Two trials have been undertaken but they lacked sufficient statistical power for reliable conclusions to be drawn.
5.8 Advice and encouragement to stop smoking are known to be more effective in some groups at particularly high risk of the adverse effects such as pregnant women, patients who have ischaemic heart disease or who have recently had a heart attack. There is no available evidence on interventions in sufferers from asthma or in others at times of stress, such as prospective fathers or people awaiting elective surgery under general anaesthesia.
Nicotine Replacement Therapy
5.9 Nicotine Replacement Therapy (NRT) approximately doubles the rate of smoking cessation from simple advice from GPs or more intensive clinic interventions.86 Nicotine 2mg chewing gum and nicotine patch are comparable in efficacy, but the nicotine patch is more convenient. NRT is best viewed as a treatment adjunct rather than as a complete treatment in itself. It will not help smokers who lack motivation to stop.
5.10 There is now compelling evidence that addiction to the drug nicotine lies at the heart of the smoking problem. It has been said that people smoke for the nicotine from cigarettes but die from the tar. Some authorities advocate a harm reduction approach and suggest that nicotine replacement products could be given to heavily dependent smokers on a long term basis to reduce exposure to toxins and reduce morbidity and mortality.87,88 The justification for this approach is not that nicotine itself is harm free, but that in a pure form it is much less harmful than smoking.89 There is a persuasive analogy which likens the cigarette to a dirty drug syringe and points to the potential benefits of a clean delivery system (NRT). Since smoking related diseases show clear evidence of dose and duration response, even partial and temporary reductions in total smoke exposure are likely to lower risk. On present evidence, nicotine from currently available pharmaceutical preparations does not pose a major threat to health.90 Nevertheless, there is an obvious need to study the effects of long term use of NRT by persistent smokers and to establish the relationship between smoking reduction and reduced incidence of disease.
5.11 Convincing support for other forms of pharmacological treatment from randomised controlled trials is lacking, but the Committee noted that the Food and Drug Administration (FDA) of America has approved the anti-depressant bupropion (see Part Nine) for smoking cessation (prescription only). The FDA has also approved, on prescription only, a new nicotine “inhaler” device. This delivers nicotine, from a cartridge, for absorption through the buccal mucosa. The device, which was also launched in the UK in January 1998, is the first to provide smokers with the hand-to-mouth ritual associated with smoking.
Increasing the Accessability to NRT Products
5.12 At present, NRT products, other than the nasal spray, are only available in the UK over the counter from pharmacists. Decreasing the cost of nicotine gum appears to increase the amount used, short-term cessation rates and attempts at cessation.91 Since 1996 NRT has been widely available in the United States and an article in the Centers for Disease Control Morbidity and Mortality Weekly Report (MMWR - 19.9.97) describes the effectiveness of a health education campaign (the Great American Smokeout), sponsored by the American Cancer Society, which included promotion of NRT products. Sales increased by 30% during one week, thought to be to new purchasers. The article concludes that “marketing and promotion efforts designed to promote attempts to quit, along with OTC (over the counter) availability of nicotine medications, are a useful part of a national strategy to decrease the prevalence of smoking”. It should be noted that the OTC category in the US is equivalent to the General Sales List in the United Kingdom. Before FDA approval was granted for OTC sales of NRT, extensive studies were performed on the safety and efficacy of these products when obtained by members of the public without health professional supervision. A paper which estimates the impact of allowing sales of nicotine medications in the US on increasing the number of smokers quitting is to be published in Tobacco Control.92
NRT and Pregnancy
5.13 Because the adverse effects of smoking in pregnancy are well known, many women stop smoking before or during pregnancy and active programmes to encourage and assist smoking cessation can achieve further cessation. Unfortunately some of the heaviest smokers continue to smoke. Nicotine replacement therapy has not been evaluated in pregnancy because nicotine probably contributes to the deficit in birthweight in the babies of cigarette smokers.93 However a review of the pharmacology of cigarette smoking and NRT has concluded that NRT results in lower plasma cotinine levels than heavy cigarette smoking, except during sleep.94 The American Agency for Health Care Policy and Research (AHCPR)84 has suggested that NRT should be offered in pregnancy to heavy smokers who cannot stop without it. This is currently not advocated in the UK, but a research evaluation of such a programme should be undertaken.
Combined Pharmacological and Psychological Treatments
5.14 The AHCPR guidelines84 recommend that both behavioural and pharmacological treatments for smoking cessation are effective components of smoking cessation treatment and should be combined. Buck et al.95 noted that these treatments provide a high degree of cost effectiveness. When nicotine replacement therapy is offered free or at reduced cost, prescriptions are more likely to be dispensed, use increases and cessation rates improve.
Research - Published Studies and Future Plans
5.15 Computerised expert systems with assessment and individualised feedback have been developed, based on the transtheoretical model of change (Prochaska, Di Clementi 1983;96 Velicer at al., 199397). This model is so called because elements of several psychological theories on human behaviour are combined. Studies of the way in which individuals had successfully changed undesirable behaviours demonstrated a pattern of progression along a pathway through stages described as pre-contemplation, contemplation, preparation, action and maintenance. Relapse was common and often a number of attempts were needed before lasting behaviour change was achieved. Prochaska and colleagues advocate the tailoring of interventions to the individual's “stage of change” and describe processes necessary to move an individual along the pathway. Preliminary data indicate that such systems, which adjust the intervention to the needs of the individual smoker, can increase long-term abstinence rates over traditional self-help methods. The Committee was informed of four proposed randomised controlled trials (RCTs) in the West Midlands which will be using adaptations of Prochaska's materials and expert computer systems.
5.16 The efficacy of aversion therapy, sensory deprivation and hypnosis are unproven. These methods may warrant further research.
Conclusions
5.17 There is evidence that advice on smoking cessation from health care professionals is effective and worthwhile.
5.18 Nicotine replacement offers a useful and effective adjunct to advice and increases cessation rates.
5.19 Nicotine replacement therapy has not been evaluated in pregnancy.
Recommendations
5.20 Smoking cessation interventions by health care professionals are worthwhile and should be encouraged.
5.21 The timing and nature of advice provided by doctors and midwives to pregnant smokers should be standardised and the effectiveness of such measures should be evaluated.
5.22 Nicotine Replacement Therapy is recommended to reduce withdrawal symptoms and improve cessation rates in smokers who are motivated to give up.
5.23 Consideration should be given to ways of increasing the availability of NRT products including via General Sales List and National Health Service prescriptions.
5.24 A randomised controlled trial is needed on the efficacy and safety of nicotine replacement therapy for pregnant women who smoke heavily and are unable to give up smoking with current advice and support.
5.25 Research is needed on the efficacy and safety of the long term use of NRT as a harm -reduction agent for smokers unable to quit.
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