Systematic Review: Smoking Cessation Intervention Strategies for Adults and Adults in Special Populations

Tobacco use is the leading cause of preventable illness and death in the United States. Once users are dependent on tobacco, quitting is difficult. Nicotine dependence resulting from tobacco use hampers efforts to sustain abstinence from tobacco for a prolonged period or a lifetime (1). Many users make multiple attempts to quit, often without the assistance that could double or even triple their chances of success (1). Proven individual cessation strategies include counseling and behavioral therapy and, except when contraindicated, first-line and second-line medications (1). These strategies may prove especially helpful for individuals motivated to quit smoking in response to pregnancy or hospitalization for a smoking-related condition. Populations with psychiatric conditions and substance abuse problems have higher rates of smoking and show a lack of responsiveness to smoking cessation treatments (2, 3). More sensitive or specialized strategies and services for smoking cessation may be needed to help patients with overlapping conditions, such as multiple addictions or psychiatric, cognitive, or medical conditions (2, 3). As background for a National Institutes of Health conference, our full systematic review (4) synthesized new evidence on individual-based strategies designed to increase the likelihood that adult tobacco users (with and without selected coexisting conditions) will quit. We also compared findings from new studies with those summarized in previous systematic reviews and meta-analyses. Methods We searched MEDLINE, the Cumulative Index to Nursing and Applied Health (CINAHL), the Cochrane Library, Cochrane Clinical Trials Register, Psychological Abstracts, and Sociological Abstracts from 1 January 1980 through 10 June 2005 using Medical Subject Headings (Appendix Table 1) as search terms or key words when appropriate. We also manually searched reference lists. A technical expert panel helped us to ensure that we included important literature in our search. Appendix Table 1. Medical Subject Headings and Text Words We limited our review to human studies conducted in developed countries and published in English (Appendix Table 2 gives specific inclusion and exclusion criteria). We considered studies with samples that consisted of participants who were age 13 years and older, that included both sexes, and that were racially and ethnically diverse. We limited studies to those with 6 months or greater follow-up periods and minimum sample sizes of 30 patients for randomized, controlled trials and 100 patients for other experimental or observational studies. We excluded articles that did not report outcomes related to quit rates; articles that did not provide the minimum information required; and all editorials, letters, and commentaries. Appendix Table 2. Smoking Cessation Strategies: Inclusion and Exclusion Criteria for New Studies All studies were dually reviewed. We assessed the quality of studies according to how well they met the criteria from the U.S. Preventive Services Task Force (5) and the National Health Service Centre for Reviews and Dissemination (6). We rated the strength of the evidence using the criteria from the Task Force on Community Preventive Services (7). To determine whether the strength of evidence for each study was strong, sufficient, or insufficient, we evaluated the study design, study execution, and the size and consistency of reported effects. For 4 of the 5 key questions in the evidence report (Appendix Table 3), we relied on several well-conducted systematic reviews. The Table documents the type, quality, treatment format, and outcome for each review. We included original research studies that 1) were published beyond the date range in the systematic reviews, 2) covered topics not covered by the reviews, and 3) provided sufficient detail about their methods and outcomes. Appendix Table 3. Key Questions for the Full Evidence Report prepared for the Agency for Healthcare Research and Quality Table. Summary of Review Article Outcomes This review was funded by a contract from the Agency for Healthcare Research and Quality. Statements in the report should not be construed as endorsement by the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services of a particular drug, device, test, treatment, or other clinical service. Data Synthesis Literature Reviewed Of 1288 abstracts, we examined 488 for full article review and retained 102 (Appendix Figure). Of 43 studies relevant to this article, 5 were of good quality (1620), 23 were fair (2143), and 15 were poor (not presented here) (4458). Appendix Figure. Tobacco use: prevention, cessation, and control article disposition. KQ = key question. *Two studies counted as one because they used the same sample. One study addressed both KQ2 and KQ5. One study used adolescents and was excluded from the review. We report on 28 new studies not included in previous reviews (Appendix Table 4). Twenty-one studies addressed strategies to improve success rates for cessation (16, 17, 21, 22, 2434, 36, 37, 39, 4143), including self-help, counseling, pharmaceutical agents, and combinations of pharmaceutical and counseling therapies. Seven studies examined interventions in patients with coexisting conditions and nicotine dependence, including psychiatric conditions and substance abuse problems (1820, 23, 35, 38, 40), and 5 studies overlapped both categories (24, 30, 31, 33, 39). We reviewed this new body of evidence both independently and within the context of previous reviews. Appendix Table 4. Smoking Cessation Intervention Strategies To Improve Success Rates for Quit Attempts Alternative Approaches to Smoking Cessation Self-Help Approaches Two studies examined a self-help approach to improving cessation rates (26, 33). One study involved patients recently discharged from intensive care units (ICUs) (33); the other included patients undergoing lung cancer screening (26). Patients discharged from intensive care received verbal encouragement to remain nonsmoking at ICU discharge, a self-help ICU rehabilitation manual, and instructions to the immediate family not to smoke near the patient. Patients undergoing lung cancer screening received either a handout listing 10 smoking cessationrelated Internet sites or 2 self-help booklets, 1 of which provided information on available pharmacotherapies for nicotine dependence (26). Patients receiving the ICU rehabilitation package were much less likely to return to smoking after discharge than were the control patients (relative risk, 0.11 [95% CI, 0.02 to 0.64]); the investigators could not determine whether just the smoking cessation advice or the whole package (including an exercise program) was responsible for the high quit rate (33). Seven-day point-prevalence quit rates did not differ significantly between patients in the intervention and control groups undergoing lung cancer screening, although at 1-year follow-up more patients in the intervention group reported an attempt to stop smoking (26). We found insufficient evidence of efficacy for self-help strategies, given the small number of new studies and discrepancies between studies for the same outcome. Counseling Five studies evaluated the effects of counseling2 studies in hospital settings (30, 39), 1 in both primary care clinics and hospitals (24), and 2 in private practices (21, 36). All interventions included nurse counseling, self-help materials, and follow-up contact either in person or by telephone; all were compared with usual care (brief advice to quit smoking, related self-help materials, or both). Although self-reported abstinence rates were higher in the more comprehensive treatment in 1 study (30), neither hospital-based intervention increased biochemically verified abstinence rates at 12 months after discharge (30, 39). At 6-month follow-up, diabetic patients seen in primary clinics and hospitals who received nurse-managed assistance in quitting were significantly more likely to quit smoking than controls (24). Biochemically validated quit rates were 17.0% for the intervention group compared with 2.3% for the control group (P= 0.001). Three different counseling interventions showed no significant differences in quit rates at 12-month follow-up (21, 36, 39). Two studies reported increased abstinence with counseling treatment (24, 30); only 1 study verified cessation biochemically (24). Although previous reviews showed that counseling was effective, these new studies show mixed results. Pharmaceutical Monotherapy Five studies examined the effect of a single pharmaceutical agent on smoking cessation (27, 28, 32, 37, 41): 3 of bupropion (27, 32, 41) and 1 each of nicotine gum (28) and transdermal nicotine and nicotine nasal spray (37). Two studies were based in hospitals (27, 41), and 3 were population-based (28, 32, 37). Two studies compared 7 weeks of sustained-release bupropion with placebo. In a 6-month study, health care workers motivated to quit smoking received behavioral counseling and sustained-release bupropion or placebo (27). Continuous smoking abstinence at week 7 was achieved by 43% of patients in the bupropion group and 18% of patients in the placebo group (P< 0.001). Side effects, although frequent, were reversible in both groups and generally consistent with those noted in previous studies. In the other study, all participants received 2 months of transdermal nicotine replacement therapy and 3 months of cognitive behavioral counseling and either sustained-release bupropion or placebo (41). The investigators observed a nonsignificant trend for abstinence at 3 months but not at 6 or 12 months among participants randomly assigned to bupropion; biochemical measures of smoking did not significantly differ between groups. Holt and colleagues (32) attempted to determine whether bupropion combined with smoking cessation counseling was effective for the indigenous Maori population of New Zealand. A