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Explore the goals of tobacco control, nicotine's impact on the brain and behavior, intervention and policy options, and implications for tobacco control policies. Learn about cessation, reducing uptake, harm reduction, and more.
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Evidence-based tobacco control: from molecule to policy Robert West University College London November 2011
Topics • The goals of tobacco control • Nicotine, the brain and behaviour • Intervention and policy options • Implications for tobacco control policies
Cessation offers the greatest scope for prevalence reduction Promoting cessation Reducing uptake 15 yr old smokers turning 16: 106K Trying to quit: 3.49M Reducing uptake Smokers Taking up smoking post 16: 165K Dying: 94K Relapsing: 3.06M Harm reduction Promoting cessation www.smokinginengland.info
Only 25% of smokers quit before they begin to lose life expectancy LLE threshold 25% Smoking Toolkit Study: www.smokinginengland.info
Nicotine Nicotine Acetylcholine Nicotinic receptor subtypes Nicotinic ACh receptor
Nicotinic receptors and the brain Nicotine receptors are prevalent throughout the brain Attention is currently focused on the VTA and NAcc
Nicotine starts to cause dependence by stimulating the brain’s main ‘reward pathway’ Rapid transport to the brain’s ventral tegmental area where nicotine attaches to acetylcholine receptors Nicotine absorbed through large surface area of the lungs Puff on cigarette This activates neural pathway leading to dopamine release in nucleus accumbens West (2009) COPD, 6, 277-283
With repeated exposure to nicotine the brain develops a ‘nicotine hunger’ and ‘cue-driven urges’ 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) Dopamine release in NAcc signals ‘reward’ and generates urge to smoke in presence of smoking cues West (2009) COPD, 6, 277-283
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
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
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 What happens when smokers stop West & Shiffman 2007
Cravings are highest in the first week but can still occur months later Unpublished data
Mood disturbance only lasts a few weeks but increased appetite persists Unpublished data
Understanding behaviour • Capability, motivation and opportunity all need to be present for a behaviour to occur • They all interact as part of a system • Motivation must be stronger for the target behaviour than competing behaviours The COM-B system Michie et al 2011 Implementation Sci
Intervention and policy options The Behaviour Change Wheel Michie et al 2011 Implementation Sci
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
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
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
Coercion as part of tobacco control • Punishing smoking • raising taxes • combating illicit supply • stigmatising smoking
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
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
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
Modelling as part of tobacco control • Showing people attractive non-smoking models • refusing to smoke • stopping smoking • using effective cessation methods
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
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
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
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
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=7,939
But only used by a tiny minority of smokers Smoking Toolkit Study: www.smokinginengland.info
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=7,939
Use of aids to cessation Smoking Toolkit Study: www.smokinginengland.info
Attempts to stop according to GP advice to stop smoking Smoking Toolkit Study: www.smokinginengland.info N=7611, p<0.001 for difference between offer of support/prescription and others
GP advice to stop smoking Percentage of smokers and recent ex-smokers for whom …; data from Smoking Toolkit Study, N=7611 www.smokinginangland.info
Use of aids to stop according to GP advice to stop smoking Offer of help is associated with greater use of prescription meds N=2714, p<0.001 for difference in use of aids Smoking Toolkit Study: www.smokinginengland.info
Association between smoking motives and attempts to quit in the past year Main barriers to quitting are identity and enjoyment 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 Smoking Toolkit Study: www.smokinginengland.info
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
Smoking prevalence before ‘smoke-free’ implementation www.smokinginengland.info
Smoking prevalence immediately after ‘smoke-free’ www.smokinginengland.info
Smoking prevalence post-recession www.smokinginengland.info
Smoking prevalence 2007-2010: social grade A-C1 A-C1: professional to clerical C2-E: skilled manual to long-term unemployed www.smokinginengland.info
Smoking prevalence 2007-2010: social grade C2-E www.smokinginengland.info