Conventional medicine is often accused of ignoring prevention, just letting preventable diseases develop, and then only treating symptoms. And the Science-Based Medicine blog is often accused of ignoring the flaws of conventional medicine and addressing things in alternative medicine that are not very important in the overall scheme of things. So this week I will address something that is undeniably important: smoking, the leading cause of preventable disease and death in the United States. I will show that conventional medicine is working diligently to prevent harm from smoking, although success rates remain low.
I subscribe to the American Academy of Family Physicians’ continuing medical education program FP Essentials. Each month they publish a monograph on a topic important to family physicians; the January 2018 monograph was on lung cancer. They give prevention priority: the whole first section (a quarter of the monograph) is devoted to Smoking Cessation. They review the scientific evidence for drugs and other methods intended to help patients stop smoking.
Not just lung cancer
The lifetime risk of lung cancer for smokers is estimated to be as high as 32% but smoking also causes harm in a lot of other ways.
The CDC fact sheet on the health effects of cigarette smoking is daunting. Smoking is the cause of 90% of deaths from lung cancer, but that’s only a small part of the harm it does. The CDC reports that:
- One in five deaths in the US are caused by smoking.
- Smoking causes more deaths than AIDS, illegal drugs, alcohol, motor vehicle injuries, and firearm-related injuries combined.
- More than 10 times as many U.S. citizens have died prematurely from cigarette smoking than have died in all the wars fought by the United States.
- Smoking increases the risk of coronary heart disease by 2 to 4 times.
- Smoking increases the risk of stroke by 2 to 4 times.
- It increases absenteeism from work and health care utilization and cost.
- It causes emphysema and bronchitis and exacerbates asthma.
- Smokers are 12-13 times more likely to die of COPD.
- It causes other cancers including bladder, blood, cervix, colon, esophagus, kidney, larynx, liver, oropharynx, pancreas, and stomach. If nobody smoked, one of every three cancer deaths in the US would not happen.
- It increases the risk of stillbirth and preterm delivery, sudden infant death syndrome (SIDS), osteoporosis, diabetes, and many other health problems.
Smoking even endangers the health of nonsmokers. Since 1964, approximately 2,500,000 nonsmokers have died from health problems caused by exposure to secondhand smoke. And in 2014, smoking-related fires caused 570 deaths, 1,140 injuries, and $426 million in property damage.
Screening for tobacco use
As of 2015, 15% of US adults were current smokers. 68% of smokers want to quit, and 55% have tried to quit in the previous year. The U.S. Preventive Services Task Force (USPSTF) recommends that physicians ask patients about tobacco use at every visit, advise them to stop, and provide behavioral and pharmacological interventions to help them stop. It recommends the use of the “5 A’s” framework:
- Ask every patient about tobacco use
- Advise all users to quit
- Assess willingness to quit
- Assist with attempts to quit
- Arrange follow-up
I don’t have any data on how many physicians are actually following these guidelines, but my impression is that most of them are. I have seen a lot of different doctors in various specialties in recent years, and at every appointment I was asked if I smoke (usually not by the doctor in person, but by a questionnaire or by auxiliary personnel), even though my medical record documents that I have never smoked.
Behavioral and other nonpharmacologic therapy
The AAFP lung cancer monograph lists these nonpharmacologic methods and assesses the published evidence for their effectiveness:
- Acupuncture – no consistent evidence of effectiveness
- Cellphone apps – no evidence available
- Cellphone text message programs – cessation rate increased from 5.6% to 9.3%
- Exercise – benefit found in some studies, not others
- Financial incentives – increase cessation rates while in place
- Hypnosis – insufficient evidence
- Pamphlets – small increase in cessation rate
- Quitlines – small increase in cessation rate
- Group therapy – doubled cessation rate
- Individual therapy – more effective than minimal behavioral intervention
Nicotine replacement (with gum, patches, lozenges, inhalers or nasal spray) has been shown to increase cessation rates by 50-70%. The number needed to treat (NNT) for one additional person to quit smoking is 15. Combining a constant delivery system (transdermal) with a faster-acting delivery method has been shown to be 50% more effective than either system alone. The gum is the least expensive, at $3 for 100 pieces.
Bupropion SR (Wellbutrin) is an antidepressant that is approved by the FDA as an adjunct for smoking cessation. There are generic versions available. The number needed to treat (NNT) for one additional person to quit smoking is 22. There are adverse effects like insomnia and dry mouth. A month’s supply costs around $20 with coupons.
Varenicline (Chantix) is a partial nicotinic acetylcholine receptor agonist that works by binding to nicotine receptors and displacing nicotine. It reduces cravings and nicotine withdrawal symptoms. It is more effective than bupropion: the NNT is 11. Combining it with nicotine replacement is not more effective than using it alone. Side effects that have been reported include nausea and nightmares. A 30-day supply costs around $287. It is approved by the FDA for 12 weeks of treatment, and if treatment is successful, it can be used for another 12 weeks.
E-cigarettes or electronic nicotine delivery systems have been used by smokers to help them stop smoking by replacing cigarettes. They have nicotine, but they don’t have all the other harmful ingredients in tobacco. There is weak evidence of their effectiveness for smoking cessation, but the long-term safety has not been established, and the AAFP feels there is not enough evidence to recommend their use. There is concern that these devices may be creating nicotine addiction in adolescents.
Governments and institutions have tried to reduce smoking through taxes, advertising bans, graphic warnings, mass media campaigns, and banning smoking in workplaces and public locations. There is weak evidence to support institutional bans, and strong evidence that legislative bans reduce harms from second-hand smoke. It has been estimated that if the legal age were raised to 21, it would prevent 50,000 deaths. The Surgeon General estimates that every 10% increase in the cost of a pack of cigarettes reduces consumption by 3-5% in adolescents and young adults.
These policies have been effective. 42% of Americans smoked in 1965. Today it is down to 15%.
Conclusion: Good news and bad
The bottom line: Every doctor (with the possible exception of some sociopaths) would rather help patients stop smoking than care for them throughout a long illness and death from lung cancer or other smoking-related condition. Mainstream medicine cares deeply about prevention and is doing its best to prevent the harmful health consequences of smoking. Doctors can screen for smoking, advise against smoking, and offer effective aids to smoking cessation, but they can only do so much. The individual smoker is ultimately responsible for his or her own behavior.
The bad news is that outside of a smoking cessation program, 95% of attempts to quit smoking fail. There may be many attempts and relapses before final success. The good news is that there are more ex-smokers than smokers.
According to the World Health Organization, “Tobacco is the only legal drug that kills many of its users when used exactly as intended by manufacturers.” Think about it.