Appendix C: the evidence
This appendix sets out the evidence statements taken from five reviews, and the expert report and links them to the relevant recommendations (see appendix B for the key to study types and quality assessments). The evidence statements are presented here without references – these can be found in the full review (see appendix E for details). It also sets out a brief summary of findings from the economic appraisal and the fieldwork.
The five reviews of effectiveness are:
Review 1: 'Rapid review of non-NHS treatments of smoking cessation'
Review 2: 'The effectiveness of National Health Service intensive treatments for smoking cessation in England'
Review 3: 'Workplace policies for smoking cessation'
Review 4: 'A review of the effectiveness of mass media interventions which both encourage quit attempts and reinforce current and recent attempts to quit smoking'
Review 5: 'The impact of quitlines on smoking cessation'.
Evidence statement 1.2 indicates that the linked statement is numbered 2 in the review 'Rapid review of non NHS treatments of smoking cessation'. Evidence statement 5.3 indicates that the linked statement is numbered 3 in the review 'The impact of quitlines on smoking cessation'.
The reviews, expert report, economic appraisal and fieldwork report are available on the NICE website. Where a recommendation is not directly taken from the evidence statements, but is inferred from the evidence, this is indicated by IDE (inference derived from the evidence).
Where the PDG has considered other evidence, it is linked to the appropriate recommendation below. It is also listed in the additional evidence section of this appendix.
Recommendation 1: evidence statements 2.1, 2.2, 2.3, 2.5, 2.17, 2.22, 2.25, 2.26, 2.27; IDE
Recommendation 2: evidence statements 2.1, 2.2, 2.3, 2.20, 2.25, 2.26, 2.27, 2.28, 2.29, 2.30; IDE
Recommendation 3: evidence statements 5.1, 5.3, 5.17; IDE
Recommendation 4: University of Birmingham 2006; NICE 2002; NICE 2007; IDE
Recommendation 5: Wang et al. 2006; IDE
Recommendation 6: evidence statements 2.1, 2.2, 2.3, 2.5, 2.9; IDE
Recommendation 7: evidence statements 2.1, 2.2, 2.3, 2.4; University of Birmingham 2006; NICE 2002; NICE 2007; IDE
Recommendation 9: evidence statements 2.1, 2.2, 2.3, 2.4; University of Birmingham 2006; IDE
Recommendation 10: evidence statements 2.1, 2.2, 2.3, 2.4; University of Birmingham 2006; NICE 2002; NICE 2007; IDE
Recommendation 11: IDE
Recommendation 12: IDE
Recommendation 13: IDE
Recommendation 14: evidence statements 2.4, 4.8, 4.24, 4.26, 4.27; Gutierrez 2007; IDE
Recommendation 15: evidence statements 2.31, 2.32, 2.34; IDE
Recommendation 16: evidence statements 3.1, 3.2, 3.3, 3.10, 3.20
Research recommendation 1: IDE
Research recommendation 2: evidence statements 2.2, 2.8, 2.17, 2.18, 2.19, 2.20, 2.21, 2.25, 2.33; IDE
Research recommendation 3: Wang et al. (2006)
Research recommendation 4: evidence statements 4.3, 4.10, 4.11, 4.21, 4.28; Gutierrez (2007)
Research recommendation 5: evidence statements 5.4, 5.13
Research recommendation 6: evidence statement 1.7
Research recommendation 7: evidence statements 1.2, 3.1
There are no controlled data available on the efficacy of Allen Carr's Easyway Programme. Two of four cohort follow-up studies report high smoking cessation rates but this evidence is weak and further research is needed to determine their effectiveness.
Level 1 (+) evidence from one randomised controlled trial shows that cytisine improves 6-month abstinence rates.
Six 3 (-) reports and one 2 (++) study provide evidence that intensive interventions for smoking cessation through the NHS Stop Smoking Services appear to be effective in the short term; on average, over half of the clients setting quit dates through the services self-report as quit at 4 weeks. However, these statistics should be treated with some caution as it appears that PCTs are using different baselines to measure success. As all seven studies took place within the English smoking cessation services, they are directly applicable to the target population.
One 3 (-) report, one 2 (-) study, two 2 (+) studies and one 2 (++) study provide evidence that intensive interventions for smoking cessation through the NHS Stop Smoking Services appear to be reasonably effective in the long term. On average, between 13% and 23% of the clients who self-report as successful quitters at 4 weeks through the services self-report as abstinent at 52 weeks – a long-term success rate that is broadly consistent with international findings. As all studies took place within the English smoking cessation services, they are directly applicable to the target population.
Evidence from two 3 (-) bulletins indicates that intermediate interventions delivered by community advisers achieve self-reported cessation rates of between 34% and 45% at 4 weeks. These results do not necessarily reflect the outcomes currently being achieved by these interventions, given the substantial development of the services since 2001. As these studies took place within English smoking cessation services, they are directly relevant to the target population.
Evidence from a 1 (++) systematic review indicates that pharmacy-delivered interventions may have a positive effect on smoking cessation rates. This finding is confirmed in a recent 2 (++) study which reports that pharmacy delivered interventions in Glasgow produce 4-week CO-validated quit rates of approximately 20%. The study also indicates that pharmacy-delivered interventions have the potential to reach and treat large numbers of smokers – especially those from disadvantaged areas. As these studies took place within UK smoking cessation services, they are directly relevant to the target population.
Two studies provide a body of 2 (++) evidence that group interventions may produce higher CO-validated quit rates at 4 weeks than one-to-one interventions. However, one-to-one interventions are also effective and many clients express a clear preference for one-to-one treatment. Moreover, in some contexts (particularly rural areas), group treatment is simply unfeasible. Therefore, one-to-one interventions are a crucial component of the NHS Stop Smoking Services as smokers need to be given a choice of treatment options. As both studies took place within the English smoking cessation services, they are directly applicable to the target population.
Information on how the site/setting impacts on the effectiveness of smoking cessation interventions is limited. Evidence from a 2 (++) study indicates that the location of treatment may indirectly influence the effectiveness of smoking cessation interventions.
As this study took place within the UK smoking cessation services, it is directly applicable to the target population.
Two 1 (++) systematic reviews provide strong evidence that smoking cessation interventions among inpatients can be effective in creating modest to substantial increases in CO-validated smoking cessation rates up to 12 months in this population. Findings from four more recent 1 (++) studies and one 1 (+) study are mixed; however, on the whole they indicate that interventions with at least 2 months post-discharge telephone follow-up are more likely to be successful than programmes of short duration. The majority of the studies took place outside of the UK in a wide range of countries including Australia, Canada, the USA and Norway. However, it is likely that their findings are applicable to the UK, given the broad similarities in these populations.
The evidence on how readily black and minority ethnic groups are accessing the stop smoking services is inconclusive. Five 3 (-) studies appear to demonstrate that black and minority groups on the whole are accessing stop smoking services in proportion with their representation within the total population; however, a high level of missing data undermines the conclusiveness of the available statistics. Moreover, indicative evidence raises some doubts about how readily black and minority ethnic groups are accessing NHS Stop Smoking Services. As these studies were conducted on the smoking cessation services in the UK, their results are directly applicable to the population under study.
There is no direct evidence on how minority ethnic status intersects with gender in relation to smoking and quit status in the context of interventions delivered through the stop smoking services. Background evidence indicates that females from black and minority ethnic groups appear to be less likely (significantly less likely in South Asian communities) to smoke than males. However, given the stigma that attaches to female smoking in many minority ethnic groups (especially South Asians), it is probable that smoking rates among minority ethnic females are underreported. Among Bangladeshi women in particular, although self-reported smoking prevalence is low, use of tobacco itself is very high (over 25%).
There is no direct evidence on how minority ethnic status intersects with social class in relation to smoking and quit status in the context of interventions delivered through the stop smoking services. Overall, background evidence indicates that for the most part, smoking in black and minority ethnic groups does not appear to be connected with social class, except in relation to Bangladeshi males – whose high smoking rates may be partly accounted for by the relative levels of social disadvantage in this ethnic group.
The evidence on how successful black and minority ethnic groups are in quitting smoking through the stop smoking services is inconclusive. One 2 (+) study found that CO-validated quitting success at 4 weeks did not vary by ethnicity. However, because of the small numbers of people from black and minority ethnic groups in the study, interpretation of their results is difficult. As this study was conducted on the smoking cessation services in the UK, its results are directly applicable to the population under study.
There is no direct evidence on how culturally appropriate the NHS Stop Smoking Services are, although it seems to be the case that there are relatively few programmes overall that cater to ethnic minorities – in most cases people from these groups are incorporated into the broader NHS. However, it appears that smoking cessation interventions tailored for minority ethnic groups can achieve high levels of success.
Five 3 (-) bulletins, one 2 (+) and one 2 (++) study provide a body of evidence that between 23% and 51% of pregnant women self-report as successful quitters at 4 weeks through the NHS Stop Smoking Services. However, given the unique challenges that pregnant smokers face, the utility of 4-week quit rates as a measure of service effectiveness is questionable. As all seven studies took place within smoking cessation services in the UK, they are directly applicable to the target population.
Background evidence indicates that there are numerous barriers to recruiting pregnant women into smoking cessation programmes. One of the most fundamental barriers to recruitment is the problem of misreport among pregnant smokers – which indicates the importance of biochemically validating smoking status. Healthcare professionals are also often unwilling to address smoking with their pregnant clients in the fear that it will jeopardise their relationship with the clients.
Three 2 (++) studies and one 2 (+) study provide a body of evidence that the NHS Stop Smoking Services have been effective overall in reaching routine and manual groups. However, one of these studies reports that there is variation within regional services, and some strategic health authorities have been less successful in reaching deprived smokers than others. As all four studies took place within the English smoking cessation services, they are directly applicable to the target population.
Six 3 (-) bulletins, one 2 (-) study, two 2 (+) studies and three 2 (++) studies provide a consistent body of evidence that people from routine and manual groups are less successful in quitting successfully (based on both self-report and CO validation) at 4 weeks than other smokers. As all twelve studies took place within the English smoking cessation services, they are directly applicable to the target population.
One 2 (+) study found that NHS stop smoking services are making a modest contribution to reducing smoking-related inequalities in health in England. As the study took place within the English smoking cessation services, it is directly applicable to the target population.
Background evidence shows that smokers from routine and manual groups face numerous social and economic barriers that may inhibit their ability to quit. In many areas of deprivation, smoking is perceived as the norm and there is no culture of quitting. Moreover, those deprived smokers who are willing to quit may have little knowledge about the effectiveness of smoking cessation interventions and may also find it difficult to attend sessions.
Background evidence shows that smokers from routine and manual groups are often more highly addicted, have been smoking since a young age, and smoke more cigarettes per week compared to professional workers, which is a key factor in explaining the lower cessation rates achieved by the NHS Stop Smoking Services in deprived areas.
According to a 2 (-) study, more flexible modes of delivery help to make smoking cessation interventions more accessible for people from deprived groups and produce 12 month self-reported quit rates of 16% – which is comparable with the long-term effectiveness of the NHS Stop Smoking Services more broadly.
Although up to 80% of prisoners in UK correctional facilities smoke, according to a recent 2 (++) report, overall a relatively small proportion of smokers (less than 10%) access smoking cessation support while in prison. However, prisoners can achieve CO-validated 4-week quit rates of over 40%, although there appear to be substantial differences in the success rates of different prisons. As this study looks at the effectiveness of the smoking cessation services in UK prisons, it is directly applicable to the target population.
Smoking is a central feature of prison life and provides relief from boredom, the stressful environment as well as facilitating group membership. Therefore, prisoners face unique problems when making a quit attempt because of the endemic levels of smoking, the lack of opportunities for distraction from cravings and negative attitudes to cessation among staff and fellow prisoners. Despite these barriers, a number of prisoners recognise the negative aspects of smoking, including its health and financial costs and evidence indicates that up to 50% of smokers in prison want help in quitting smoking.
Although it appears that rates of smoking are particularly high among people in mental health institutions in the UK, there is no available information on how effective smoking cessation support is in this setting.
People with mental illnesses in institutional settings face a variety of barriers in accessing services and quitting smoking. Smoking cessation in this setting can be complicated by factors such as physiological vulnerability to nicotine addiction, the fact that nicotine may reduce the side effects of some medications, the positive effects of nicotine on the brain, and the use of cigarettes as a behavioural reward and lack of access to cessation support.
Overall, it appears that workplace interventions in the context of 'environmental support' (workplace smoking restrictions and educational campaigns) are effective in facilitating smoking cessation. One 2 (+) American study found that a smoking cessation programme delivered in the context of a workplace smoking ban and educational campaign produced long-term success rates similar to smoking cessation programmes more broadly. Another 1 (-) American study found that environmental support may increase the success of workplace interventions, at least in the short term. Two 2 (-) studies have identified Allen Carr workplace seminars to be an effective means of facilitating smoking cessation in the workplace. Online smoking cessation programmes have also been highlighted in a 4 (+) report as a potentially effective way of facilitating smoking cessation in the workplace. However, evidence on the effectiveness of these interventions types is presently weak and further research is needed to determine their effectiveness.
A 1 (++) systematic review and a 1 (+) meta-analysis of the available international literature indicates that the most effective smoking cessation interventions in workplace settings are those interventions that have proven effectiveness more broadly. There is strong evidence that group therapy, individual counselling and pharmacological treatments all have an effect in facilitating smoking cessation. However, both reviews failed to identify effects due to particular intervention type. There is also evidence that minimal interventions including brief advice from a health professional are effective. Self-help manuals appear to be less effective, although there is limited evidence that interventions tailored to the individual have some effect.
Two 1 (++) systematic reviews of international studies indicate that financial incentives are most commonly used by employers to encourage employee compliance with smokefree workplace policies and the uptake of smoking cessation support. While the addition of incentives does not appear to increase the quit rates of smoking cessation interventions in the workplace, there is some evidence that such incentives do improve recruitment rates into worksite cessation programmes, which may lead to higher absolute numbers of successful quitters in the long term. There is also some evidence that incentives may delay relapse to smoking, even if they don't prevent it altogether.
A 1 (++) systematic review indicates that workplace interventions may have the potential for higher participation rates than other contexts, and also provide the opportunity to access smokers who would otherwise not be accessible. These represent significant potential outcomes of workplace interventions.
Workplace smoking bans and smokefree legislation should be carefully planned, include the input of smokers, and be accompanied by provision of help and support for smokers. Public support for bans and legislation can be strengthened by using media campaigns to inform the public about the adverse health effects of passive smoking and by treating the issue as a worker protection law rather than a consumer protection law. An effort should be made to understand diversity, and materials and messages should be culturally appropriate. An adequate revenue base is crucial to support the implementation of legislation.
There is level 2 (+) evidence, probably relevant to the UK population, indicating that the addition (to a web-based self-help style smoking cessation intervention) of an automated email educational messaging system was associated with an increase in the 30-day intent to treat quit rates (7.5% vs. 13.6%, p = 0.035).
There is evidence from a level 1&2 (+) review, probably relevant to the UK population, that multi-channel mass media campaigns (combined with other interventions) are effective in increasing tobacco use cessation. Cessation rates in the intervention groups ranged from 3.9% (confirmed) to 50% (self-reported), with a median of 7% in follow-up periods of 6 months to 5 years. There is evidence from another review (level 2 [-]), possibly relevant to the UK population, that shows that media campaigns and concurrently implemented tobacco control programmes (or policies) are associated with a reduction in the net smoking prevalence of between 6–12%. Other level 2 (-) and 3 evidence reported either inconclusive results, or in the case of a Dutch campaign (3), estimated the follow-up point prevalence abstinence rate attributable to the campaign as 4.5% after control for test effects and secular trends. There is level 1 (+) evidence, probably relevant to UK workplaces, which found that adding peer group support and lottery incentives to mass media-based self-help interventions led to abstinence levels of 19.5% in the control group compared with 30% in the intervention group at 2 years.
There is level 1 (++) evidence, probably relevant to the UK population, which found that a web-based smoking cessation programme using more extensive information on coping strategies and health risks is more effective at the contemplation stage than shorter programmes with less health-related information at 3 months. There were statistically significant differences in quit rates in smokers using the more extensive programme (OR=1.54, 95% CI: 1.18-2.02, p=.002). There is level 1 (+) evidence, probably relevant to the UK population, that a behavioural intervention for smoking cessation delivered via an Internet website can achieve a quit rate of 12.3% at 3 months (compared with 5% of controls). There is level 2 (-) and 3 evidence, probably relevant to the UK population, which reported that other web-based smoking cessation sites can achieve quit rates of up to 18%.
There is level 1 (++) evidence, probably relevant to the UK population, that a text message-based intervention can increase smoking cessation rates (28% vs 13%, RR 2.20, 95% CI: 1.79 to 2.70, p < 0.0001) at 6 weeks.
There is level 2 (-) evidence, probably relevant to UK college and university students, which shows a positive effect of an Internet-based smoking cessation intervention on smoking cessation. There is level 3 evidence, possibly relevant to young people in the UK, that reports reductions in smoking and quit attempts in rural teens after using an Internet-based virtual reality 'world' for smoking cessation. There is level 3 evidence, probably relevant to young people in the UK that an integrated web and text-messaging programme may result in quit rates of 17%.
There is level 2 (-) and 3 evidence, probably relevant to the UK population, that posters or printed media can be an effective way of increasing awareness of campaigns. No studies were identified which evaluated the effectiveness of interventions of different duration.
There is level 1 (+) evidence, probably relevant to UK workplaces, that television message recall is associated with increased smoking cessation rates. There is level 3 evidence, probably relevant to the UK, which indicates that the more TV episodes watched or recalled, the higher the incidence of self-reported quitting or abstinence from smoking. There is level 3 evidence, probably relevant to the UK, which indicates that the effectiveness of a web-based cessation programme is increased according to the amount of exposure to educational materials. There is level 3 evidence, probably relevant to the UK adult population, that the relative risk for quitting was estimated to be 10% higher for every 5000 units of exposure to state anti-tobacco television advertising over a 2 year period. However, these results did not achieve statistical significance. There is level 2 (+) evidence, directly relevant to the UK population, that varying the intensity of TV adverts does not have an effect on smoking cessation.
There is level 2 (-) evidence, which is probably relevant to the UK population, which suggests that advertisements depicting suffering as a result of tobacco use may be instrumental in promoting cessation or reinforcing the decision to quit. There is level 3 evidence, probably relevant to UK teens, that indicates that dissonance-arousing messages specifically targeting girls can have positive short-term effects on quit rates. There is also level 3 evidence that shows that graphic mass media messages about the negative consequences of smoking among adults has a positive effect on quit attempts among young people (18% of smokers in the sample attempted to quit [95% CI: 14% to 22%]). Finally, there is level 2 (-) evidence providing insufficient evidence that longer positive messages are less effective than short, negative messages.
Four studies (both qualitative and quantitative) evaluated outcomes such as the acceptability and usage of web-based interventions. One qualitative study reported that participants sought online smoking cessation resources for reasons of convenience, timeliness, anonymity and because their current information needs were unmet. Another level 1 (+) study, probably relevant to the UK population, found that the optional sections of an intervention most used/viewed were setting a quit date, and the descriptions of pharmacological aids. A level 2 (-) study reported that the 'Ask an expert' section was rated most highly. The fourth study (level 2 [-]) reported that the intervention helped to raise consciousness about quitting, encouraged behavioural goals, provided stages of change feedback, and offered interactivity in presenting information and strategies about quitting. No studies were identified which evaluated the views of those delivering the intervention. No studies were identified which assessed inequalities of access.
Two 1 (+) studies found that reactive quitlines improved abstinence rates over the distribution of self-help materials alone. Three 2 (+) studies provide further support for the effectiveness of quitlines, and found self-report 12-month abstinence rates of between 8.2% and 15.6%. As two of these studies took place in the UK, and results are broadly consistent across studies, these findings are likely to be directly applicable to a UK setting.
There is strong evidence from a 1 (++) Cochrane Review and one 1 (+) meta-analysis that proactive telephone counselling has a modest effect on smoking cessation. As these reviews are international in scope their findings are likely to be applicable to a UK setting.
Although there is limited available evidence regarding the comparative effectiveness of proactive and reactive quitlines, one 2 (+) study found that self-reported 12-month abstinence rates were somewhat higher for proactive compared with reactive support – although the difference was not statistically significant. Although the study was conducted in Northern Europe, its results are likely to be broadly applicable to a UK setting.
Further research needs to be conducted into the effectiveness of telephone counselling for minority ethnic groups as the existing limited evidence is inconclusive. A 1 (-) study found that the addition of telephone counselling did not improve the effectiveness of a smoking cessation intervention aimed at African American smokers above and beyond a provider-prompted intervention and self-help materials. A second 1 (+) study found that enhanced telephone counselling for Hispanic smokers did significantly increase abstinence rates, when demographic and smoking-related variables were controlled. As these studies were conducted in the USA, which has a different ethnic composition to the UK, their results are not directly applicable to a UK setting.
Although further research is needed regarding the cost-effectiveness of quitlines, a cost-effectiveness analysis of the Swedish national quitline (+ rating) found it to be particularly cost effective: the researchers calculate the cost per year of life saved as equivalent to USD 311–401. A 2 (+) study of the cost of quitlines also deems them to represent a very modest expense for governments that provide these services, although a 3 (+) case report warns that services need to be marketed to large populations to be effective.
Although these studies were conducted outside of the UK, the costs of running a national quitline are likely to be similar from one country to the next. Therefore, their findings are likely to be broadly applicable to a UK setting.
NICE (2002) Guidance on the use of nicotine replacement therapy (NRT) and bupropion for smoking cessation. NICE technology appraisal 39. [Replaced by NICE public health intervention guidance 10]
NICE (2007) Varenicline for smoking cessation. NICE technology appraisal 123.
Overall, brief advice, individual behavioural counselling, group behaviour therapy, pharmacotherapies, self-help materials, telephone counselling and quitlines were cost effective compared with no intervention.
Group counselling was more cost effective than individual counselling. Brief advice and more intensive counselling, when combined with either NRT or bupropion, was more cost effective than either advice or counselling provided on its own. NRT and bupropion, combined with advice or counselling, was more cost effective than either NRT or bupropion provided on its own. Varenicline was cost effective compared with either bupropion, NRT or placebo.
The nicotine-assisted reduction to stop (NARS) approach, supported by intensive counselling, was cost effective for people who were initially unwilling to quit smoking (or unwilling to quit without cutting down first) compared with counselling on its own. This estimate assumes that those undertaking CDTQ would not have made an abrupt quit attempt: it is generally more cost effective for people to attempt quitting abruptly rather than make an initial attempt by first cutting down using CDTQ.
No-one can ever be sure in advance whether a mass media campaign will work, but if such a campaign succeeds by encouraging even a comparatively small number of people to stop smoking, it will be cost effective. The more successful campaigns will be extremely cost effective.
Methods of assisting pregnant women to quit smoking are cost effective if the women do not return to smoking after the birth of the baby. Insufficient evidence was available to determine whether home visits by specialist stop smoking professionals were cost effective compared with attending stop smoking clinics, using NRT or attempting to quit without assistance.
Fieldwork aimed to test the relevance, usefulness and the feasibility of implementing the recommendations and the findings were considered by the PDG in developing the final recommendations. For details, go to the fieldwork section in appendix B and online.
Fieldwork participants who work with people who smoke and other tobacco users were generally very positive about the recommendations and their potential to improve the provision of smoking cessation services and help people to stop smoking. Many stated that the recommendations were easy to read and understand. They also said they gave them a clear understanding about who to target and the types of smoking cessation products and services that are effective. They welcomed the fact that the recommendations were evidence-based.
PCT staff hoped the recommendations would encourage decision-makers to provide them with the resources they need to deliver an effective, responsive, smoking cessation service.
Although participants agreed that all healthcare professionals should be able to offer people brief advice on smoking and, where necessary, refer them to smoking cessation services, some felt this would not be feasible within the available resources. In addition, some healthcare professionals, particularly hospital staff and dentists, questioned the value of involving them in brief interventions and referrals. However, smoking cessation practitioners thought it was helpful that the guidance encouraged hospital staff to provide smoking cessation advice and make referrals.
PCT staff and practitioners who are involved in workplace stop-smoking schemes hope that this guidance will help expand this work.
Most participants agreed that smoking cessation advisers should be trained and should receive further training on a continuing basis, but relatively few knew whether the training they had received complied with national standards.