domingo, 10 de julio de 2011

Quit Smoking Success Rates


Quit Smoking Success Rates
‘what’s the best way to quit smoking?’



Most people are unaware of the success rates of the various methods used to quit smoking. Yet every year thousands of people make the decision to quit smoking. For many of them it will not be the first time they have tried to stop smoking. The majority will restart smoking within 1 year.
This raises a basic question: what are the quit smoking success rates of the most widely used techniques?
This is a short review of the evidence.
Statistics from studies show that the success rate of ‘going cold turkey’ is quite low – between 4% and 10%.
Hughes JR, Keely J, Naud S., "Shape of the relapse curve and long-term abstinence among untreated smokers." Addiction 2004;99:29-38 showed a 12 month success rate of less than 5%.
Doran, C.M. et al, (2006) “Smoking status of Australian general practice patients, and their quit attempts.” Addictive Behaviours 31: 758 – 766 showed an overall cessation rate for NRT with other support of just over 30%.
A review of the data in 2009 showed a 6 month abstinence rate with NRT of only 6.8%: BMJ 2009; 338:b1024
Stead LF, Perera R, Bullen C, et al; "Nicotine replacement therapy for smoking cessation." Cochrane Database Syst Rev. 2008 Jan 23;(1) also showed low long term effectiveness for NRT.
In the UK a recent review by the National Institute for Health and Clinical Excellence (NICE) of the ‘Cut Down to Quit with Nicotine Replacement Therapy’ programme showed success rates with NRT of only 6.8%! 
British Medical Journal 1983; 286(6366):595 – showed a 10% effectiveness rate for nicotine gum at 1 year.
Addictive Behaviors 1983; 8(3):253 – showed an 8% success rate for nicotine gum at 1 year.
Preventive Medicine 1995; 24(1):41 – showed a 13% success rate for nicotine patches at 1 year.
New England Journal of Medicine, 1999;340(9):685 – showed a 16% success rate for nicotine patches at 1 year.
Using NRT while pregnant exposes the unborn child to a dose of nicotine.
Using NRT patches while breastfeeding gives the baby a dose of nicotine. Breastfeeding within a hour of using nicotine gum significantly increases the amount of nicotine in breast milk.
People with a medical condition such as heart disease, an overactive thyroid gland, diabetes, severe kidney or liver disease, or stomach ulcers should exercise caution before deciding to use NRT – discuss with your doctor first.
NRT delivers a dose of nicotine, so it may cause nicotine-related side-effects such as: headaches; dizziness; a racing pulse; vivid dreams; indigestion; dry mouth; nausea; diarrhoea. Nicotine patches may cause skin irritation. Nicotine gum may cause heartburn, sore throat, or dry mouth. Nicotine inhalers may cause nasal irritation.
Bupropion is an ant-depressant drug that has been shown to reduce cravings on smoking cessation. Treatment is for a minimum of 8 weeks and a maximum of 12 weeks. Studies show efficacy of up to 25%.
According to the manufacturer’s own Zyban prescribing information leaflet, the efficacy varies, with one study producing a 1 year success rate of 23% (28% if a nicotine patch is added!), while another study produced a 6 month success rate of only 19%.
Tonnesen P, Tonstad S, Hjalmarson A, Lebargy F, Van Spiegel P I, Hider A, Sweet R, Townsend J (2003). "A multicentre, randomized, double-blind, placebo-controlled, 1-year study of bupropion SR for smoking cessation". J Intern Med 254 (2): 184–192. showed one year success rates of only 21% (11% for a very small group of patients who received placebo).
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Jorenby D E, Hays J T, Rigotti N A, Azoulay S, Watsky E J, Williams K E, Billing C B, Gong J, Reeves K R (2006). "Efficacy of varenicline, an alpha4beta2 nicotinic acetylcholine receptor partial agonist, vs placebo or sustained-release bupropion for smoking cessation: a randomized controlled trial". JAMA 296 (1): 56–63. showed the 1 year abstinence rates for bupropion to be only 14.6% (compared to 10.3% in the placebo group). Treatment was discontinued due to side-effects in 12.6% of the bupropion group.
Doran, C.M. et al, (2006) “Smoking status of Australian general practice patients, and their quit attempts.” Addictive Behaviours 31: 758 – 766 showed an overall cessation rate for bupropion of just 21%.
Only one study has shown a higher efficacy (Hays JT, Hurt RD, Rigotti NA, et al. Sustained release bupropion for pharmacologic relapse after smoking cessation. Ann Intern Med 2001; 135:423-33., which produced a 55.1% success rate) but the patients in the study had to take bupropion continuously for 1 year (instead of 12 weeks) to achieve that level of efficacy. In other words, even taking bupropion all the time for a year, only about half of smokers remain abstinent – the other half continuing to take bupropion and continuing to smoke!
The manufacturer’s prescribing information leaflet advises that bupropion should not be prescribed (is contraindicated) to individuals with seizure disorders (e.g epilepsy or other conditions that lower the seizure threshold, such as alcohol withdrawal or benzodiazepine discontinuation), anorexia nervosa, or bulimia. It is also contraindicated in people who are also taking monoamine oxidase inhibitors (MAOIs). When switching from MAOIs to bupropion, it is important to include a washout period of about two weeks between the medications.[72] The prescribing information also recommends that caution should be exercised when treating patients with liver damage, severe kidney disease, and severe hypertension, as well as in paediatric patients, adolescents and young adults due to the increased risk of suicidal ideation. 
According to the prescribing information, the most common side-effects of Zyban are dry mouth, and insomnia. Patients have also reported stomach pains, vivid dreams, joint pain, coughing, itchiness, nausea, and sore throat.
Jorenby D E, Hays J T, Rigotti N A, Azoulay S, Watsky E J, Williams K E, Billing C B, Gong J, Reeves K R (2006). "Efficacy of varenicline, an alpha4beta2 nicotinic acetylcholine receptor partial agonist, vs placebo or sustained-release bupropion for smoking cessation: a randomized controlled trial". JAMA 296 (1): 56–63. showed a 1 year abstinence rate of 23% (14.6% for Zyban, 10.3% for placebo), with a drop-out rate due to side-effects of 10.5%.
A 2010 report by West & Shiffman suggested that varenicline produces a success rate of about 16%.
Varenicline has a range of side-effects, with nausea being the major problem. It may also cause: abdominal pain; flatulence; dyspepsia; constipation; dry mouth; rash; breathing problems; headache; increased appetite; decreased appetite; alterations to taste (dysgeusia); tiredness; insomnia; abnormal dreams or nightmares.
In 2008 the WHO stated that it does not consider e-cigarettes a legitimate therapy for smokers trying to quit because there is no scientific evidence (peer reviewed studies)that show efficacy or safety.
In a recent (December 2010) report, investigators from the University of California (Riverside) expressed concerns over safety and lack of clinical data, suggesting that the regulators (FDA) should take them off the market until there have been proper safety investigations.
A 2008 report in New Zealand (Murray Laugesen (2008). "Safety Report on the Ruyan e-cigarette Cartridge and Inhaled Aerosol". Health New Zealand Ltd. ) found traces of carcinogenic tobacco specific nitrosamines (TSNA) in tested e-cigarettes.
At the time of writing (December 2010) no e-cigarette has been licensed in the UK as a medicinal NRT product.
A two-part review by Cui Meng (Cui Meng, Advances in studies on acupuncture abstinence, Journal of Traditional Chinese Medicine, 1995, 15(4): 301–307, and Cui Meng, Advances in studies on acupuncture abstinence (continued), Journal of Traditional Chinese Medicine 1996; 16 (1): 65–69.) of a large number of clinical research papers suggests that the long term success rate (cessation at 1 year) for ear acupuncture is 30%.
An individual study in 2004 by Ausfeld-Hafter et al suggested a 41% 1 year success rate. (Ausfeld-Hafter B, Marti F, Hoffmann S. Forsch Komplementarmed Klass Naturheilkd. 2004 Feb;11(1):8-13.
Doran, C.M. et al, (2006) “Smoking status of Australian general practice patients, and their quit attempts.” Addictive Behaviours 31: 758 – 766 showed an overall cessation rate for of 53.4% for hypnotherapy.
Another review has shown a success rate of just over 66% - but this required 4 sessions of hypnosis.
Kline, M.(1970) International Journal of Clinical and Experimental Hypnosissuggested a 1 year success rate of 88%.
Crasilneck, H. B., & Hall, J. A. (1985). Clinical hypnosis: Principles and applications (2nd ed.) Orlando, FL: Grune & Stratton, quote a success rate of over 67%.
Comparison table
Method of quitting1 year success rate
Willpower aloneLess than 10%
Nicotine patches & gum alone6.8% - 16%
bupropion (Zyban)14.6% - 25%
varenicline (Champix / Chantix)16% - 23%
e-cigarettesNo published data
Acupuncture30% - 41%
Hypnosis53.4% - 88%

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