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1 Evidence-based tobacco control: from molecule to policy University College London November 2011 Robert West
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2 Topics The goals of tobacco control Nicotine, the brain and behaviour Intervention and policy options Implications for tobacco control policies
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3 Goals of tobacco control Reduce total harm from tobacco use Reduce use Reduce uptake Promote cessation Reduce harm from use
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4 Cessation offers the greatest scope for prevalence reduction Smokers 15 yr old smokers turning 16: 106K Taking up smoking post 16: 165K Relapsing: 3.06M Trying to quit: 3.49M Dying: 94K www.smokinginengland.info Reducing uptake Promoting cessation Harm reduction Promoting cessation Reducing uptake
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5 Only 25% of smokers quit before they begin to lose life expectancy Smoking Toolkit Study: www.smokinginengland.info LLE threshold 25%
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6 Nicotine Acetylcholine Nicotinic ACh receptor Nicotinic receptor subtypes
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7 Nicotinic receptors and the brain Nicotine receptors are prevalent throughout the brain Attention is currently focused on the VTA and NAcc
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8 Nicotine starts to cause dependence by stimulating the brain’s main ‘reward pathway’ Puff on cigarette Nicotine absorbed through large surface area of the lungs Rapid transport to the brain’s ventral tegmental area where nicotine attaches to acetylcholine receptors West (2009) COPD, 6, 277-283 This activates neural pathway leading to dopamine release in nucleus accumbens
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9 With repeated exposure to nicotine the brain develops a ‘nicotine hunger’ and ‘cue-driven urges’ Dopamine release in NAcc signals ‘reward’ and generates urge to smoke in presence of smoking cues Cue-driven urges to smoke Need to smoke to relieve nicotine hunger After repeated exposure the brain reward system is damaged and develops a ‘nicotine hunger’ (a need for nicotine when CNS concentrations are depleted) West (2009) COPD, 6, 277-283
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10 Cigarette addiction involves nicotine dependence and psychological factors Nicotine dependence –cue-driven urges –nicotine hunger Psychological factors –social reward –positive beliefs about smoking (e.g. it relieves stress) Usually diminish over first month or two Can persist for years West (2009) COPD, 6, 277-283
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11 Most relapse occurs in the first week of the quit attempt Period of strong urges and adverse symptoms: depression, anxiety, poor concentration, irritability, restlessness West et al (2007) Thorax, 62, 998-1002
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12 What happens when smokers stop First few weeks –strong urges to smoke –increased irritability –increased depression –increased anxiety –increased restlessness –increased hunger –reduced concentration –sleep disturbance –increased cough –mouth ulcers –constipation –weight gain Later –sporadic urges to smoke –reduced anxiety –increased life satisfaction –hunger –weight gain –reduced cough –reduced exacerbations –possibly increased blood pressure –reduced risk of CHD –stabilised risk of lung cancer West & Shiffman 2007
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13 Cravings are highest in the first week but can still occur months later Unpublished data
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14 Mood disturbance only lasts a few weeks but increased appetite persists Unpublished data
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15 Understanding behaviour 1.Capability, motivation and opportunity all need to be present for a behaviour to occur 2.They all interact as part of a system 3.Motivation must be stronger for the target behaviour than competing behaviours The COM-B system Michie et al 2011 Implementation Sci
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16 Intervention functions (EPICTREME) EducationIncreasing knowledge or understanding PersuasionUsing communication to induce positive or negative feelings or stimulate action IncentivisationCreating expectation of reward CoercionCreating expectation of punishment or cost TrainingImparting skills RestrictionUsing rules that limit engagement in the target behaviour or competing or supporting behaviour Environmental restructuring Changing the physical or social context ModellingProviding an example for people to aspire to or imitate EnablementIncreasing means/reducing barriers to increase capability or opportunity
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17 Policy options Comms/marketingUsing print, electronic, telephonic or broadcast media GuidelinesCreating documents that recommend or mandate practice. This includes all changes to service provision FiscalUsing the tax system to reduce or increase the financial cost RegulationEstablishing rules or principles of behaviour or practice LegislationMaking or changing laws Env/Soc PlanningDesigning and/or controlling the physical or social environment Service provisionDelivering a service
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18 Intervention and policy options The Behaviour Change Wheel Michie et al 2011 Implementation Sci
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19 Linking COM-B to intervention functions EdPICTREnvMEna CPh CPs OPh OSo MA MR
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20 Examples: Promoting smoking cessation C: Lack of knowledge of why or how to stop smoking Education C: Capacity for self-control overpowered by drive to smoke Enablement M: Lack of concern about effects of smoking on self or others Persuasion, Incentivisation, Coercion M: Liking being ‘a smoker’Persuasion O: Frequent exposure to prompts to smoke Environmental restructuring O: Ability to smoke anywhereRestriction
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21 Education as part of tobacco control Increasing knowledge and understanding about tobacco use and cessation –effect on life-expectancy –effect on pain and disability –effect on mental health –consequences of use of different forms of tobacco –importance of stopping as young as possible –effect on other people –tobacco industry tactics –best ways of stopping
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22 Persuasion as part of tobacco control Changing the way people feel about tobacco use –reminding of importance of stopping smoking –associating smoking with negative imagery –creating positive imagery around not smoking –making effective methods of stopping attractive –countering tobacco company promotion
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23 Incentivisation as part of tobacco control Giving people rewards for not smoking –rewards for not taking up smoking –rewards for abstinence –rewards for use of effective methods of achieving abstinence
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24 Coercion as part of tobacco control Punishing smoking –raising taxes –combating illicit supply –stigmatising smoking
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25 Training as part of tobacco control Providing people with the skills to avoid or escape from tobacco use –refusal skills training –self-control training –training in effective use of cessation methods
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26 Restriction as part of tobacco control Making rules about what, when and where people can smoke –banning high-tar cigarettes –banning smoking in indoor public areas –banning smoking in cars with children in
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27 Environmental restructuring as part of tobacco control Restricting availability –removing vending machines –reducing outlet density –preventing sales to minors Reducing smoking prompts –Reducing tobacco promotion –Reducing exposure to smoking in films etc
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28 Modelling as part of tobacco control Showing people attractive non-smoking models –refusing to smoke –stopping smoking –using effective cessation methods
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29 Enablement as part of tobacco control Helping people resist or stop smoking –addressing psychological problems that pre-dispose to smoking –providing medicines to combat craving and withdrawal symptoms, block nicotine’s effects and substitute for positive functions –providing non-pharmacological substitutes for smoking –providing behavioural support to aid cessation
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30 Other key considerations Affordability –What can be afforded within the resources that can be devoted to it Practicability –What is the best implementation that can be achieved Acceptability –What is ethically and publicly acceptable
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31 Relevant evidence from the UK Education: –quitting younger, better use of NRT bought OTC, and more use of Stop Smoking Services Persuasion: –more effective use of GP advice Coercion: –more effective use of cost increases Restriction: –examine how to make them work better Enablement –Raise the quality and increase affordability of Stop-Smoking support Arnott D (Ed) All Party Parliamentary Group Report on Tobacco Control in England. London: ASH www.ash.org.uk
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32 Education
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33 Percentage of ever regular smokers who have quit for at least a year Green Line: A-C1; Blue Line: C2-E, Red Line: All Plateau in quitting at the crucial point in lifespan Smoking Toolkit Study: www.smokinginengland.info
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34 Specialist Stop Smoking Services give the best results Significantly better than no aid adjusting for confounding variables, p<0.001 Data from www.smokinginengland.info; based on smokers who tried to stop in the past year who report still not smoking at the survey adjusting for other predictors of success (age, dependence, time since quit attempt, social grade, recent prior quit attempts, abrupt vs gradual cessation): N=7,939www.smokinginengland.info
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35 But only used by a tiny minority of smokers Smoking Toolkit Study: www.smokinginengland.info
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36 Little evidence for benefit of OTC NRT as currently used Data from www.smokinginengland.info; based on smokers who tried to stop in the past year who report still not smoking at the survey adjusting for other predictors of success (age, dependence, time since quit attempt, social grade, recent prior quit attempts, abrupt vs gradual cessation): N=7,939www.smokinginengland.info
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37 Use of aids to cessation Smoking Toolkit Study: www.smokinginengland.info
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38 Persuasion
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39 Attempts to stop according to GP advice to stop smoking N=7611, p<0.001 for difference between offer of support/prescription and others Smoking Toolkit Study: www.smokinginengland.info
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40 GP advice to stop smoking Percentage of smokers and recent ex-smokers for whom …; data from Smoking Toolkit Study, N=7611 www.smokinginangland.info
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41 Use of aids to stop according to GP advice to stop smoking N=2714, p<0.001 for difference in use of aids Offer of help is associated with greater use of prescription meds Smoking Toolkit Study: www.smokinginengland.info
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42 Association between smoking motives and attempts to quit in the past year Final model from forward stepwise logistic regression of attempt to stop in past 12 months on to beliefs about smoking. Odds ratios less than 1 represent negative associations. N=3033 Main barriers to quitting are identity and enjoyment Smoking Toolkit Study: www.smokinginengland.info
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43 Coercion
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44 Key pieces of evidence from the Smoking Toolkit Study: cost of smoking Increased cost of smoking can translate to reduced consumption but no increase in toxin intake or quit attempts N=10,920 smokers; includes hand- rolled; p<0.001 for increased cost per cigarette, decrease in cigarette consumption, and decrease in quit attempts Smoking Toolkit Study: www.smokinginengland.info
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45 Restriction
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46 Smoking prevalence before ‘smoke-free’ implementation www.smokinginengland.info
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47 Smoking prevalence immediately after ‘smoke-free’ www.smokinginengland.info
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48 Smoking prevalence post-recession www.smokinginengland.info
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49 Smoking prevalence 2007-2010 : social grade A-C1 www.smokinginengland.info A-C1: professional to clerical C2-E: skilled manual to long-term unemployed
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50 Smoking prevalence 2007-2010 : social grade C2-E www.smokinginengland.info
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51 Association between motives to stop smoking and attempts to quit in the past year Final model from forward stepwise logistic regression of attempt to stop in past 12 months on to beliefs about smoking. Odds ratios less than 1 represent negative associations. N=5647 Potential negative impact of restrictions on motivation to stop www.smokinginengland.info
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52 Quit attempts pre- and post- smoking ban Base: smoked in last year; p<.05 for decline; www.smokinginengland.info Attempts to stop smoking were not higher post-ban
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53 Success of quit attempts pre- and post- smoking ban Base: made quit attempt in last month; p<.05 for increase post-smoke-free; www.smokinginengland.info Attempts to stop smoking were more successful post-ban
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54 Enablement
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55 Performance of the NHS Stop Smoking Services varies considerably Impact=Number of 4-week, CO-verified quitters generated above what would have been expected from medication alone (25% success rate) per 100,000 adult population: Data from Information Centre Negative impact means less than 25% CO-verified success rate
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56 Medication options used CO-validated 4-week abstinence a OR (95% CI) p value Medication Single NRT vs no medication 1.75 (1.39-2.22)<0.001 Combination NRT vs single NRT 1.42 (1.06-1.91)0.019 Bupropion (Zyban) vs single NRT 1.12 (0.96-1.30)0.160 Varenicline (Champix) vs single NRT 1.78 (1.57-2.02)<0.001 Brose L, West R, McDermott M, Fidler J, Croghan E, McEwen A (In Press) What makes for an effective stop-smoking service? Thorax.
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57 Treatment type CO-validated 4-week abstinence a OR (95% CI) p value Intervention type (reference: one-to-one) Closed group 1.43 (1.16-1.76)0.001 Drop-in 0.72 (0.57-0.90)0.003 Open (rolling) group 1.46 (1.19-1.78)<0.001 Telephone support* -- Other 0.97 (0.68-1.38)0.851 Brose L, West R, McDermott M, Fidler J, Croghan E, McEwen A (In Press) What makes for an effective stop-smoking service? Thorax.
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58 Treatment setting CO-validated 4-week abstinence a OR (95% CI) p value Intervention setting (reference: Specialist clinics) Primary care 0.80 (0.66-0.99)0.037 Pharmacy 0.94 (0.83-1.06)0.303 Other 0.87 (0.69-1.10)0.239 Brose L, West R, McDermott M, Fidler J, Croghan E, McEwen A (In Press) What makes for an effective stop-smoking service? Thorax.
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59 Back to the molecules: treatment options Nicotine Varenicline Cytisine Nortriptyline Bupropion
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60 Conclusions Nicotine from cigarettes rewards smoking and punishes abstinence, partly tied to specific cues Smokers build up rituals, beliefs, identity and culture around cigarettes The ultimate solution is to make smoked tobacco undesirable (remove nicotine) or unavailable and to provide nicotine in pure form for those who want it In the meantime for countries such as the UK: –Educate on best ways of stopping –Maintain salience of cessation as a priority –Provide optimal treatment for cigarette addiction –Promote environmental restructuring to minimise exposure to smoking cues
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