Cigarette smoking continues to be the leading preventable cause of disease and death in the United States.1,2 There are more than 5 million deaths per year worldwide associated with tobacco use.3A high percentage of smokers attempt to quit each year; however, smoking cessation success rates are low. Patients who are counseled by a nurse practitioner (NP), including short counseling interventions, are almost twice as likely to attempt quitting than patients not counseled by an NP.4
Smoking accounts for approximately 443,000 deaths per year in the United States. 1 It is responsible for 0.9 million lung cancer deaths, and approximately 1 million chronic obstructive pulmonary disease (COPD) deaths.2 The Centers for Disease Control and Prevention (CDC) reports that in 2010, 19.3% percent of adults 18 or older smoked—an all-time low.1,5,6 Smoking rates are more common in men (21.5%) than in women (17.3%). The highest rates of smoking in adults are among American Indians, Alaska Natives, and adults who live below poverty level. The highest prevalence rates are found in West Virginia, the Midwest (21.8%) and the South (21.0%). Tobacco use costs more than $193 per year in the United States.1,3
Smoking addiction is both physical and mental. The etiology of tobacco dependence is multidimensional and includes physiological, psychological, and social/behavioral factors. Nicotine has been found to be as addictive as other drugs such as cocaine or heroin.7 The research also shows that nicotine acts on the central nervous system as a stimulant and causes the release of dopamine and norepinephrine.8 When the brain no longer receives the nicotine supply, intense withdrawal symptoms emerge; this nicotine addiction drives the smoking habit.2
When smoke is inhaled, the nicotine is carried deep into the lungs, absorbed into the bloodstream, and carried to other parts of the body. Over time, the individual becomes physically and emotionally dependent on nicotine. Research shows that smokers must overcome both physical and psychological dependence to cease smoking. As the smoking pattern increases, the person adapts to nicotine and develops tolerance, which increases smoking behavior.7
Psychological factors related to tobacco dependence are the result of experiencing pleasurable sensations from smoking, while physiological factors include increased dopamine levels in the brain. Social/behavioral factors include forming a daily habit of smoking, and smoking used as self-medication to reduce stress or unpleasant cravings that occur with tobacco withdrawal.
Acute and chronic effects of nicotine
Cilia lining the bronchial tube of the lungs become paralyzed with the first inhalation of cigarette smoke. Nicotine is quickly absorbed into the bloodstream, affecting the heart, hormones, metabolism, and brain. Carbon monoxide (CO) found in smoke causes the heart to pump harder. During pregnancy, nicotine crosses the placenta and can be found in the umbilical cord blood of newborns.7 Cigarette smoke contains carcinogens that lodge in several parts of the body; the lung is one of the initial organs where carcinogens are stored, thereby predisposing the smoker to lung cancer. Regular smokers will have nicotine or by-products, such as cotinine, in the bloodstream for 3 to 4 days after they cease smoking.7
Over several years, smoking activity increases to a point at which plasma nicotine levels are maintained. These processes result in smoking patterns that are highly resistant to change and, when interrupted, cause strong emotional desires to smoke. The physiological addiction to nicotine causes the person to smoke even more while awake. The person cannot stop smoking without craving more cigarettes and experiencing withdrawal symptoms such as anxiety, irritability, difficulty concentrating, and changes in appetite.9
When withdrawal symptoms occur, a person smokes to increase blood levels of nicotine. The individual then develops a chronic tolerance and continues to smoke for a longer period of time while increasing the amount of cigarettes smoked.
Findings to support smoking cessation
Smoking cessation decreases the risk of serious or chronic diseases, such as cardiovascular diseases including myocardial infarction (MI) and stroke, nonmalignant respiratory diseases such as COPD and asthma, and many forms of cancer such as lung, mouth, uterine cervix, pharynx, and kidney. Women who stop smoking before or during early pregnancy reduce the risk of having low-birth-weight babies.7–10
It is critical for NPs to screen patients for smoking behavior at every visit (see Smoking history questionnaire).9 Physical dependence on nicotine is measured using the Fagerström Test for Nicotine Dependence (FTND).11 The FTND measures how long a patient waits to smoke after awakening (see Items and scoring for FTND). The FTND has acceptable levels of internal consistency (coefficient alpha = 0.61), and is closely related to biochemical indices of heaviness of smoking.11 The use of the aforementioned questionnaires will ensure that the NP screens each patient appropriately for smoking cessation treatment.
NPs should obtain a complete family history (FH) and patient medical history (PMH). The NP should note FH and PMH of heart disease, respiratory disease, or cancer. During the history of present illness for a patient presenting with chest symptoms, sputum production, cough (amount of sputum per day and characteristics), shortness of breath, recurrent respiratory infections, and exercise tolerance should be explored.12 The NP should assess the patient's past attempts at quitting by including integral questions about the length of smoking cessation, number of prior attempts, problems with past attempts, and assess the reasons for relapse. Social and dietary history should be taken into consideration and include an assessment of alcohol, coffee, and tea consumption since smokers tend to have increased intake of these substances.4 All smokers should be initially screened for depression as it is two times more common in this population, and has been linked to failures in cessation treatments.13,14
The physical exam should include a thorough physical assessment with particular attention to vital signs and BP, which, if elevated, suggests the additional risk of cardiopulmonary disease. The NP should examine the nose, ears, sinuses, mouth, dentition, lips, and pharynx, noting evidence of tobacco irritation. The patient's clothing, hair, or breath will smell of tobacco. Physical findings in smokers include yellow teeth, stained fingers, odor of smoke, gingivitis, and productive sputum.12 A thorough respiratory and cardiovascular physical exam should also be conducted. Dyspnea, coughing, and wheezing may be indicative of respiratory diseases related to smoking behavior.15 The rate, depth, and rhythm of the patient's breathing should be observed. For an adult, the normal respiratory rate is 12 to 20 breaths per minute. Exhalation generally lasts twice as long as inhalation, but in patients with COPD secondary to smoking, it can take four times longer.16 Cardiovascular assessment should include noting increased BP, decreased peripheral blood flow, and cardiac dysrhythmias. The patient's weight should be recorded as many adults will gain 5 to 10 pounds during the first few months after quitting smoking.12
The NP should consider ordering spirometry testing for all smokers. If the results are normal, smoking cessation strategies can be initiated before signs of respiratory disease occur. In smokers with COPD, the chest radiography will reveal hyperexpansion of the lungs, and spirometry will reveal airflow obstruction when emphysema is present.12 The NP should screen all adult patients for lipid disorders. Careful screening can determine if there are other risk factors for heart disease in addition to smoking status.
A urine sample can be obtained, especially in research studies of smoking cessation drugs, to determine if urinary cotinine, a metabolite of nicotine, is present. CO measurement in exhaled air can also be used.4 Saliva testing can be used to detect cotinine levels.4
When smokers visit a healthcare provider, they may leave the office without ever being asked, advised, assessed, or assisted with smoking cessation. NPs are uniquely positioned to facilitate smoking cessation for their patients. Smoking cessation interventions should be offered to all tobacco users during each visit to the NP's office. According to the Agency for Health Care Research and Quality, NPs should incorporate smoking cessation as a regular part of clinical care for all who smoke or use tobacco products.17
Over 50% of all current smokers have, at one time, used a smoking treatment to stop smoking.1 Choosing the right treatment plan is critical for success. Taking the patient's past quitting attempts into account helps the NP develop an individualized plan. If cravings and withdrawal symptoms were barriers in the past, then the use of medications should be encouraged.18 If there is failure with a treatment program, the NP should assess the reasons for failure and suggest a new quit attempt with modified treatment that addresses the reasons for the failed attempt such as stress, poor treatment compliance, or withdrawal symptoms.19
The process for smoking cessation success begins with the five A's; Ask, Advise, Assess, Assist, and Arrange. Ask the patient at every visit if there is a desire to quit smoking. Advise all smokers to quit; offering brief nonjudgmental advice at every office visit has been shown to be effective in helping smokers to quit.18Assess readiness to quit. Even if the smoker is not ready to quit, the NP has developed a safe and caring environment for the smoker when he or she is ready to quit. Assist with treatment options including medications, behavioral modification, physical activity, weight management, or a combination of therapies. Arrange follow up visits with the patient and offer praise when the patient is successful.17
First-line medications: Nicotine replacement therapies
First-line medications for smoking cessation are nicotine replacement therapies (NRTs) such as nicotine gum, nicotine inhaler, nicotine lozenge, nicotine nasal spray, nicotine patch, and two nonnicotine mediations: varenicline and bupropion sustained-release tablets.
NPs should advise all patients to stop smoking while using NRT products because NRTs contain pure nicotine without other carcinogens delivering 1/3 to 2/3 the concentration produced by cigarette smoking. Smoking while using NRTs can cause an MI or angina. Before prescribing an NRT, assess the smoker's severity of nicotine dependence and NRT preferences.20 Before prescribing an NRT, assess the smoker's severity of nicotine dependence with the FTND.
Since all NRTs are of similar efficacy and do not have significant adverse reactions, the smoker should choose their preferred medication after the pros and cons are explained. The average use for NRTs is 12 weeks but can be prescribed for up to 9 months if necessary.21
The nicotine patch is placed on the skin and releases a small, steady amount of nicotine to the body. Nicotine patches contain varied amounts of nicotine (21, 14, or 7 mg) and the user reduces the dose over time.20 Nicotine lozenges look like hard candy and are placed in the mouth to dissolve slowly. The nicotine lozenge (2- or 4-mg dose of nicotine) releases nicotine as it slowly dissolves in the mouth. The dosing guide rule is if the first cigarette is smoked within 30 minutes of waking, the 4-mg lozenge should be used; and if the first cigarette is smoked after 30 minutes of waking, then the 2-mg lozenge should be used.22
Nicotine gum is chewed to release nicotine that is absorbed through tissue inside the mouth. The user chews the gum until it produces a tingling feeling, then places it between the cheek and gum tissue. When the tingling stops, the sequence is repeated until the tingling is gone (usually within 30 minutes). Nicotine gum products have varied amounts of nicotine (2 mg or 4 mg) to allow users to reduce the amount of nicotine in their bodies.22 A nicotine inhaler is safe and effective but because it is prescription only, it is used less than other NRT options. The nicotine inhaler has lower abstinence rates due in part to its design and/or usage. Smokers experience a more difficult draw compared to a cigarette resulting in more work to get sufficient quantities of nicotine to prevent withdrawal symptoms.23 Nicotine nasal spray is available by prescription only in 10 mg/mL form and is rapidly absorbed in the bloodstream.22
Compliance with the amount and duration of use of NRTs is low. Smokers who use NRTs as recommended are more likely to quit. The effectiveness of NRTs is increased when NPs promote and encourage adherence. One way to accomplish this is to give patients written and verbal instructions on the use, dosage, and side effects of the NRT.23
First-line medications: Nonnicotinic
Varenicline (Chantix) and bupropion sustained-release tablets (Zyban) are the only nonnicotine front-line drugs for smoking cessation. Varenicline and bupropion reduce cravings and withdrawal symptoms during smoking cessation. Both medications have the potential risk for depression and suicide. Smokers have a higher level of suicidal risk than those who do not smoke.21 There is also a high rate of smokers among patients with a mental illness who use smoking as a way to decrease the intensity of their symptoms.24 The person's history of mental illness, especially depression and suicidal risk, should be assessed before this medication is prescribed. Ongoing assessment of relevant symptoms is also necessary.25
Varenicline is a nicotine receptor partial agonist and should not be taken with any nicotine replacement therapy.26 Varenicline blocks the brain's reaction to the pleasure of nicotine, so if the person smokes, the associated pleasure is minimized.25 Since it takes 1 week to take effect, it is advised to start the quit date 1 week after beginning the medication. It is the only first-line medication that has significant long-term relapse prevention up to 52 weeks. One-third of all patients experience nausea, so the medication should be taken after meals with an 8-ounce glass of water. Constipation, sleep disturbances, strange dreams, and headaches are also potential side effects. The FDA has issued a black box warning to the varenicline package insert about serious psychiatric events and advises patients who experience these events to stop taking the drug immediately and contact the healthcare provider.27
Bupropion (Zyban) stabilizes the levels of dopamine and norepinephrine and is prescribed for up to 12 weeks. Since long-term treatment may promote success, maintenance therapy for a longer timeframe, may be prescribed based on individual patient need. Since it takes up to 2 weeks to take effect, it is advised to start the quit date 2 weeks after beginning the medication.28 Bupropion is contraindicated if the patient has a history of seizure disorders or diagnosis of anorexia or bulimia. Insomnia, strange dreams, and dry mouth are listed as potential side effects.29 The FDA has issued a black box warning to the bupropion package insert stating that patients should be closely monitored for depression, suicidal ideation, and suicide attempts. The healthcare provider should be contacted immediately if the patient notices these symptoms.30
Smoking cessation rates can be improved with the combination of medications. The nicotine patch can provide stable nicotine levels and the addition of another NRT such as the lozenge can provide emergency relief in certain situations such as a stressful event.31 Another option is to combine medications using a NRT (nicotine patch) and the nonnicotine medication (bupropion).
Two second-line medications, clonidine and nortriptyline, are effective, but have a greater risk of adverse reactions and are only recommended when first-line medications or combination therapies have not been effective or have been contraindicated. The use of clonidine and nortriptyline should be considered on an individual basis.32 The FDA has not endorsed their use for the treatment of smoking cessation, and use of these medications for smoking cessation is considered off-label.
Smokers are four times more likely to quit if they are given ongoing behavioral support. Behavioral therapy/counseling is an effective tool for smoking cessation. Behavioral therapy is highly effective in helping smokers to quit, but only moderately effective in establishing a prolonged change.33
Behavioral therapy may include telephone conversations or individual and group counseling support. All modes of counseling require considerable time and effort on the NP's part. Environmental distractions in the patient's home should be considered when developing a phone intervention. Prearranged times, the number and length of calls should be confirmed with patients during the office visit. Smokers who are not motivated to quit are unlikely to participate in follow-up telephone sessions.19
Counseling can offer smokers a supportive environment to help them develop coping skills, learn stress reduction techniques, and develop social support outside of treatment.34 NPs should encourage smokers to make a public declaration of their quit attempt, including a quit date, and make their homes smoke-free before their quit date. NPs can also teach the smoker how to replace smoking with nonsmoking activities such as exercise. Since smoking behaviors are connected to a variety of triggers such as stress, foods, and drinking, education about healthy behaviors should be included in the sessions. Developing coping strategies to overcome the urge to smoke is also essential. Sessions devoted to deep breathing and relaxation techniques, medication, and stress reductions are important as well.35
Hypnotherapy and acupuncture
Hypnosis is the combination of deep concentration and a therapeutic relationship to assist a patient to alter perception and/or behavior. The aim of hypnotherapy in smoking cessation is to decrease the desire to smoke or strengthen the will to stop smoking.36 The patient is guided by the hypnotherapist to respond to suggestions for changes in the smoking experience. Treatment success can be influenced by the therapeutic relationship or the hypnotisability of the patient. In a review of 11 clinical studies, hypnotherapy did not improve smoking cessation rates.37
Acupuncture involves the insertion of fine needles into specific acupuncture points for 15- to 20-minute sessions. Several acupuncture techniques have been used to treat smoking cessation. Inserting needles in specific points of the ear are designed to decrease cravings and irritability related to smoking cessation.38The needles can be held in place with surgical tape for several days and patients are instructed to press the needles when they become aware of withdrawal symptoms. The Cochrane Review concluded that there is no consistent evidence that acupuncture is effective for smoking cessation.36
Physically active smokers live longer than inactive ones. Regular exercise is a successful aid to smoking cessation. Physical activity reduces tobacco cravings and reduces postcessation weight gain. Patients suffering from stress, anxiety, and depression during a smoking cessation attempt have been able to reduce the intensity of these symptoms while participating in physical activity. Patients exercising in short bouts of moderate-to-intense exercise 10 to 20 minutes daily experience a reduced desire to smoke and fewer withdrawal symptoms.39
Although vigorous exercise increases smoking cessation rates, it is more appropriate to prescribe moderate-intensity exercise. The intensity range should be between 60% and 70% of the maximal heart rate for each age group.25 Since exercise interventions for smoking cessation have a poor success rates, NPs should individualize the exercise program based on age, level of fitness, and exercise preferences.40 Results are positive when exercise is conducted in groups and supervised by professionals. Patients should establish the exercise regimen 3 to 4 weeks before the target quit date to improve success rates.
NPs should prescribe aerobic lifestyle-type exercises such as walking, cycling, swimming, or running. The activity should ideally be an hour long with warm-up and cool-down periods. Because smokers are typically sedentary, the exercise should be tailored to the individual smoker beginning with 20 minutes of activity 7 days a week and then progress to 60 minutes of continuous daily physical activity.34
Fear of weight gain prevents many tobacco users from quitting. NPs have an obligation to inform smokers there is a high probability of a 5- to 10-lb weight gain during the smoking cessation process.9 Cognitive behavioral therapy has been shown to be an effective approach to achieving weight loss and prevent weight gain.40 Nicotine gum produces less weight gain during smoking cessation than other forms of NRT most likely due to the oral manipulation of the gum. Success in changing eating behaviors of weight-conscious smokers has a positive impact on smoking behaviors. The NP can play a vital role by identifying weight-conscious smokers, who are not ready to quit smoking, and offer them cognitive behavioral therapy programs or direct patients to dieticians for weight control. Interventions for weight-conscious smokers focus on reducing weight concerns through cognitive behavioral therapy, improving body image, adding an exercise program, and adding a weight management program, all in conjunction with a smoking cessation program.29
An integration of approaches using pharmacology, counseling, and exercise has been effective in smoking cessation attempts. Exercise combined with NRT improves exercise capacity and delays weight gain in female smokers. Adopting exercise as a lifestyle change prior to cessation of smoking along with the traditional NRT and behavioral therapy may increase the success rate of smoking cessation.
Currently, NRT and bupropion are the standard pharmacological smoking cessation treatments. Although NRT and bupropion have been moderately successful in reducing the severity of acute cravings and withdrawal symptoms, relapse rates for smoking are often high after 6 months. Exercise in combination with drug therapy can be effective in reducing relapse as well.20
The best approach for smoking cessation involves multiple interventions and continuous support. NPs should remember that most smokers require several attempts at cessation before they are successful. Health promotion and risk reduction are the NPs' primary goals when looking to help patients quit smoking.
2. McPhee SJ, Papadakis MACurrent Medical Diagnosis and Treatment 2011, 50th ed. New York: McGraw-Hill Medical; 2011:8.
4. Dunphy LMHPrimary Care: The Art and Science of Advanced Practice Nursing, 2nd ed. Philadelphia, PA: F.A. Davis; 2007:1248.
6. Zanis DA, Hollm RE, Derr D, et al.Comparing intervention strategies among rural, low SES, young adult tobacco users. Am J Health Behav. 2011;35(2):240–247. Accessed 28 September 2011.
8. Zanis DA, Hollm RE, Derr D, et al.Comparing intervention strategies among rural, low SES, young adult tobacco users. Am J Health Behav. 2011;35(2):240–247.
9. Chaney SE, Sheriff SWeight gain among women during smoking cessation: Testing the effects of a multifaceted program. AAOHN journal: official journal of the American Association of Occupational Health Nurses. 2008;56(3):99–105. Accessed 28 September 2011.
11. Heatherton TF, Kozlowski LT, Frecker RC, Fagerström KThe fagerström test for nicotine dependence: A revision of the fagerström tolerance questionnaire. Br J Addict. 1991;86(9):1119–1127.
12. Dains JE, Baumann LC, Scheibel PAdvanced health assessment and clinical diagnosis in primary care, 3rd ed. Edinburgh: Elsevier Mosby; 2007:562.
13. Piper ME, Smith SS, Schlam TR, et al.Psychiatric disorders in smokers seeking treatment for tobacco dependence: relations with tobacco dependence and cessation. J Counsult Clin Psychol. 2010;78(1)13–23.
14. Thomas LA, Supiano KP, Chasco EE, McGowan J, Beer MCSmoking cessation programs for seniors: a group model that works. Clin Gerontol. 2009;32(1):118–125.
15. Efraimsson EÖ, Hillervik C, Ehrenberg AEffects of COPD self-care management education at a nurse-led primary health care clinic. Scand J Caring Sci. 2008;22(2):178–185.
16. Yeh ML, Chang CY, Chu NF, Chen HHA six-week acupoint stimulation intervention for quitting smoking. Am J Chin Med. 2009;37(5):829–836.
17. Fiore MC, Jaen CR, Baker TB, et al.Treating Tobacco Use and Dependence: 2008 update. Clinical Practice Guideline. Rockville, MD: U.S. Department of Health and Human Services. Published Health Service. 2008.
18. Agboola S, McNeill A, Coleman T, Leonardi Bee JA systematic review of the effectiveness of smoking relapse prevention interventions for abstinent smokers. Addiction. 2010;105(8):1362–1380.
19. Vangeli E, Stapleton J, West RSmoking intentions and mood preceding lapse after completion of treatment to aid smoking cessation. Patient Educ Couns. 2010;81(2):267–271.
20. Mills EJ, Wu P, Lockhart I, Wilson K, Ebbert JOAdverse events associated with nicotine replacement therapy (NRT) for smoking cessation. A systematic review and meta-analysis of one hundred and twenty studies involving 177,390 individuals. Tob Induc Dis. 2010;8:8.
21. Garrison GD, Dugan SEVarenicline: a first-line treatment option for smoking cessation. Clin Ther. 2009;31(3):463–491.
22. Bostock-Cox BUsing Pharmacotherapy to optimize quit rate in smokers. Nursing Prescribing. 2010;8(9):417–421.
23. Biazzo LL, Froshaug DB, Harwell TS, et al.Characteristics and abstinence outcomes among tobacco quitline enrollees using varenicline or nicotine replacement therapy. Nicotine and Tobacco Research. 2010;12(6):567–573.
24. De Azevedo RCS, Mauro MLF, Lima DD, Gaspar KC, da Silva VF, Botega NJGeneral hospital admission as an opportunity for smoking-cessation strategies: a clinical trial in brazil. Gen Hosp Psychiatry. 2010;32(6):599–606.
25. Arbour-Nicitopoulos KP, Faulkner GE, Cohn TA, Selby PSmoking cessation in women with severe mental illness: exploring the role of exercise as an adjunct treatment. Arch Psychiatr Nurs. 2011;25(1):43–52.
26. Grassi MC, Enea D, Ferketich AK, Lu B, Pasquariello S, Nencini PEffectiveness of varenicline for smoking cessation: a 1-year follow-up study. J Subst Abuse Treat. 2011;41(1):64–70.
27. Kaur K, Kaushal S, Chopra SVarencline for Smoking Cessation: A review of the Literature Department of Pharmacology, volume 70, number 1, Feb. 2009.
28. Gifford EV, Kohlenberg BS, Hayes SC, et al.Does acceptance and relationship focused behavior therapy contribute to bupropion outcomes? A randomized controlled trial of functional analytic psychotherapy and acceptance and commitment therapy for smoking cessation. Behav Ther.
29. Levine MD, Perkins KA, Kalarchian MA, et al.Bupropion and cognitive behavioral therapy for weight-concerned women smokers. Arch Intern Med. 2010;170(6):543–550.
30. Gray KM, Carpenter MJ, Baker NL, et al.Bupropion SR and contingency management for adolescent smoking cessation. J Subst Abuse Treat. 2011;40(1):77–86.
31. Haug S, Meyer C, Ulbricht S, et al.Predictors and moderators of outcome in different brief interventions for smoking cessation in general medical practice. Patient Educ Couns. 2010;78(1):57–64.
32. Polosa R, Benowitz NLTreatment of nicotine addiction: present therapeutic options and pipeline developments. Trends Pharmacol Sci. 2011;32(5):281–289.
33. Eisenberg MJ, Blum LM, Filion KB, et al.The efficacy of smoking cessation therapies in cardiac patients: a meta-analysis of randomized controlled trials. Can J Cardiol. 2010;26(2):73–79.
34. Sallit J, Ciccazzo M, Dixon ZA cognitive-behavioral weight control program improves eating and smoking behaviors in weight-concerned female smokers. J Am Diet Assoc. 2009;109(8):1398–1405.
35. Selby P, Voci SC, Zawertailo LA, George TP, Brands BIndividualized smoking cessation treatment in an outpatient setting: predictors of outcome in a sample with psychiatric and addictions co-morbidity. Addict Behav. 2010;35(9):811–817.
36. Elkins G, Marcus J, Bates J, Hasan Rajab M, Cook TIntensive hypnotherapy for smoking cessation: a prospective study. Int J Clin Exp Hypn. 2006;54(3):303–315.
37. Barnes J, Dong CY, McRobbie H, Walker N, Mehta M, Stead LFHypnotherapy for smoking cessation. Cochrane Database Syst Rev. 2010:CD001008.
38. Wing YK, Lee AL, Wong LYAuricular Acupressure for Smoking Cessation: A Pilot Randomized Controlled Trial. Medical Acupuncture. 2010;22(4).
39. Ayán Pérez CPrescribing exercise in tobacco smoking cessation therapy. Arch Bronconeumol. 2009;45(11):556–560.
40. Collins BN, Nair U, Hovell MF, Audrain-McGovern JSmoking-related weight concerns among underserved, black maternal smokers. Am J Health Behav. 2009;33(6):699–709.