Importance
It has been estimated that in 2018 nearly 20% of adults in the US were currently using a tobacco product.
Objective
To systematically review the effectiveness and safety of pharmacotherapy, behavioral interventions, and electronic cigarettes for tobacco cessation among adults, including pregnant persons, to inform the US Preventive Services Task Force.
Data Sources
PubMed, PsycInfo, Database of Abstracts of Reviews of Effects, Cochrane Database of Systematic Reviews, Centre for Reviews and Dissemination of Health Technology Assessment; surveillance through September 25, 2020.
Study Selection
Systematic reviews of tobacco cessation interventions and randomized clinical trials that evaluated the effects of electronic cigarettes (e-cigarettes) or pharmacotherapy among pregnant persons.
Data Extraction and Synthesis
Independent critical appraisal and data abstraction; qualitative synthesis and random-effects meta-analyses.
Main Outcomes and Measures
Health outcomes, tobacco cessation at 6 months or more, and adverse events.
Results
Sixty-seven reviews addressing pharmacotherapy and behavioral interventions were included as well as 9 trials (N = 3942) addressing e-cigarettes for smoking cessation and 7 trials (N = 2285) of nicotine replacement therapy (NRT) use in pregnancy. Combined pharmacotherapy and behavioral interventions (pooled risk ratio [RR], 1.83 [95% CI, 1.68-1.98]), NRT (RR, 1.55 [95% CI, 1.49-1.61]), bupropion (RR, 1.64 [95% CI, 1.52-1.77]), varenicline (RR, 2.24 [95% CI, 2.06-2.43]), and behavioral interventions such as advice from clinicians (RR, 1.76 [95% CI, 1.58-1.96]) were all associated with increased quit rates compared with minimal support or placebo at 6 months or longer. None of the drugs were associated with serious adverse events. Five trials (n = 3117) reported inconsistent findings on the effectiveness of electronic cigarettes on smoking cessation at 6 to 12 months among smokers when compared with placebo or NRT, and none suggested higher rates of serious adverse events. Among pregnant persons, behavioral interventions were associated with greater smoking cessation during late pregnancy (RR, 1.35 [95% CI, 1.23-1.48]), compared with no intervention. Rates of validated cessation among pregnant women allocated to NRT compared with placebo were not significantly different (pooled RR, 1.11 [95% CI, 0.79-1.56], n = 2033).
Conclusions and Relevance
There is strong evidence that a range of pharmacologic and behavioral interventions, both individually and in combination, are effective in increasing smoking cessation in nonpregnant adults. In pregnancy, behavioral interventions are effective for smoking cessation, but data are limited on the use of pharmacotherapy for smoking cessation. Data on the effectiveness and safety of electronic cigarettes for smoking cessation among adults are also limited and results are inconsistent.
Despite progress in reducing the use of tobacco products by US adults, in 2019 an estimated 20.8% of adults in the US currently used any tobacco product and there are persistent differences in rates of smoking by age, sex, and race/ethnicity.1 A large range of pharmacologic and behavioral methods are available to help adults quit tobacco use2; however in a 2015 survey, among those who tried quitting in the previous year, only 31.2% reported using evidence-based cessation treatments and 7.4% were successful in quitting.3
In 2015, the US Preventive Services Task Force (USPSTF) issued 4 recommendations related to tobacco cessation interventions among adults. Two A recommendations were given for behavioral and pharmacotherapy interventions for adults and for behavioral interventions for pregnant women, and 2 I statements were issued: one for pharmacotherapy interventions for pregnant women and one on the use of electronic cigarettes (e-cigarettes) for tobacco cessation among adults and pregnant women.4 The objective of this review was to inform updated recommendations by the USPSTF.
This is an update of a 2015 overview of reviews that supported the 2015 USPSTF recommendation.5,6 An analytic framework and 3 key questions (KQs) guided the review (Figure). Consistent with the 2015 review, an overview of reviews method was primarily used for this update. However, given the insufficient evidence found in 2015, original searches and syntheses of primary evidence were conducted for the benefits and harms of e-cigarettes for smoking cessation and for the benefits and harms of pharmacologic smoking cessation interventions among pregnant women. Details are available in the full report.8 All main results presented in the full report are also presented in this article; more detailed methods, including review selection and determination of overall credibility and quality of individual reviews and studies, and additional effect estimates for specific types of interventions and comparative effectiveness outcomes, are provided in the full report.
Data Sources and Searches
Three separate literature searches were conducted (eMethods in the Supplement). All searches were restricted to articles in the English language published since January 2014. For reviews, the following databases were searched through April 2019: PubMed, PsycINFO, the Database of Abstracts of Reviews of Effects, the Cochrane Database of Systematic Reviews (CDSR), and the Centre for Reviews and Dissemination Health Technology Assessment. For primary evidence on e-cigarettes, the CDSR, Cochrane Central Register of Controlled Clinical Trials (CENTRAL), PsycInfo, PubMed, and Scopus were searched through May 2020. For studies of pharmacotherapy tobacco cessation interventions among pregnant women, Medline, CENTRAL, PubMed, and PsycInfo were searched through May 2020. Ongoing surveillance for relevant primary literature and Cochrane systematic reviews was completed through September 25, 2020.
Two researchers independently reviewed all identified abstracts and full-text articles against prespecified eligibility criteria (eTable 1 in the Supplement). Studies were included if they were systematic reviews, with or without meta-analysis, that examined the effectiveness of tobacco cessation interventions for adults. Interventions targeting cessation of any tobacco product, including e-cigarettes, were included and reviews that focused on specific interventions (eg, nicotine replacement therapy [NRT], group counseling) and specific subpopulations (eg, persons with serious mental illness) were eligible. Reviews published by Cochrane and non-Cochrane reviews were included. Narrative (nonsystematic) reviews and other overviews of reviews were excluded. Only the most recent version of updated reviews was included. Separate inclusion criteria were outlined when considering primary evidence related to e-cigarettes and pharmacotherapy interventions among pregnant women (eTable 1 in the Supplement).
Data Extraction and Quality Assessment
One reviewer completed the AMSTAR-2 (Assessment of Multiple Systematic Reviews 2) tool9 to rate the credibility of the systematic reviews under consideration for inclusion, and a second reviewer provided an independent assessment using the same tool for all reviews rated critically low. For primary studies, 2 reviewers independently assessed the risk of bias of included evidence using study-design specific criteria. Each review and study were assigned a quality rating of “good,” fair,” or “poor” according to the USPSTF study design–specific criteria (eTable 2 in the Supplement).7 Reviews rated as having critically low credibility and primary studies rated as poor quality were excluded. Data from each included review and primary study were abstracted into detailed abstraction forms using DistillerSR. For all included evidence, one reviewer completed primary data abstraction and a second reviewer checked all data for accuracy and completeness.
Data Synthesis and Analysis
Given the large number of reviews that met eligibility criteria and the overlapping scope and evidence between many of them, a method was developed to identify 1 or more reviews within each population and intervention group that represented the most current and applicable evidence. These reviews served as the basis for the main findings. All other reviews were examined for complementary or discordant findings. Pooled point estimates presented in the included reviews were reported when appropriate; none of the individual study evidence was reanalyzed. Data from trials of e-cigarette use were not meta-analyzed, given the few number of studies and data reporting. Methods for the meta-analyses of data from trials of pharmacotherapy among pregnant women are described in the full evidence report.
For the overview of reviews method, the strength of the overall body of evidence assigned within the primary systematic review was reported. In most cases, these grades were based on the Grading of Recommendations Assessment, Development and Evaluation working group definitions, which consider study limitations, consistency of effect, imprecision, indirectness, and publication bias. Where strength of evidence grades were not available, including for the primary evidence syntheses, an overall strength of evidence grade was assigned based on consensus discussions involving at least 2 reviewers.10
This review addressed 2 populations of interest: the general adult population and pregnant women. Within each population, results are organized by KQ.
For the overview of reviews, investigators reviewed 1173 abstracts and 210 full-text articles for possible inclusion for all KQs (eFigure 1 in the Supplement). Sixty-four reviews were identified that met eligibility criteria, including those among an unselected population of adults and those limited to a specific subgroup of adults (Table 1).11-53,57-77 Thirty-two reviews were designated as primary reviews.11-16,18-20,22,24-30,32-34,38,41,43,45,46,48-53,78 Eleven additional reviews had overlapping evidence with the primary reviews.17,21,23,31,35,37,39,40,42,44,47 Results of these reviews were consistent with the primary reviews in terms of effect magnitude and statistical significance and are not discussed further. Twenty-one reviews focused on specific subpopulations of adults (eg, people with severe mental illness, smokeless tobacco users).57-77 These 21 reviews are not discussed here but are included in the full report.8
The review of primary evidence on the use of e-cigarettes for smoking cessation resulted in 9 included randomized clinical trials (RCTs) reported in 16 publications; 5 of these RCTs addressed smoking cessation (KQ2) and all addressed potential harms (KQ3) (eFigure 2 in the Supplement).79-94 None of the e-cigarette trials reported results related to health outcomes (KQ1).
Health Benefits of Interventions
Key Question 1. Do tobacco cessation interventions improve mortality, morbidity, and other health outcomes in adults who currently use tobacco?
One RCT (n = 1445) reported the results of a behavioral tobacco cessation intervention on health outcomes.95 This study reported no statistically significant differences between intervention and control groups in rates of total mortality (41.5% vs 44.%, P = .93), coronary heart disease mortality (17.3% vs 19.9%, P = .87), and lung cancer incidence (7.8% vs 8.8%, P = .89) at 20-year follow-up among men at high risk for cardiorespiratory disease.96
Cessation Benefits of Interventions
Key Question 2. Do tobacco cessation interventions increase tobacco abstinence in adults who currently use tobacco?
Among the general adult population, there was strong evidence from systematic reviews that the combination of pharmacotherapy and behavioral support, all 7 US Food and Drug Administration–approved medications (all forms of NRT, bupropion, varenicline), and a variety of behavioral interventions were statistically significantly associated with an increase in smokers’ relative likelihood to quit smoking at 6 or more months as compared with smokers receiving usual care or a minimal stop-smoking intervention (Table 2).
The pooled risk ratio (RR) for smoking abstinence at 6 months or more for combined pharmacotherapy plus behavioral support vs usual care or minimal support control groups was 1.83 (95% CI, 1.68-1.98; 52 trials; n = 19 488).11 Average quit rates in these trials ranged from 2% to 50% (mean, 15.2%) among participants receiving pharmacotherapy and behavioral support vs 0% to 36% (mean, 8.6%) among participants randomized to a control group.
There was also evidence of an association between the use of NRTs, bupropion, and varenicline and smoking abstinence at 6 months or more (Table 2). The pooled RR for abstinence for NRT was 1.55 (95% CI, 1.49-1.61; 133 trials; n = 64 640)12; for bupropion, 1.64 (95% CI, 1.52-1.77; 46 trials; n = 17 866)15; and for varenicline, 2.24 (95% CI, 2.06-2.43; 27 trials; n = 12 625)16 when compared with placebo or no drug. In all cases, behavioral support to quit smoking was provided to both intervention and control participants. There was also an association between combined NRT (typically a long- and short-acting therapy) and quitting at 6 months or more (RR, 1.25 [95% CI, 1.15-1.36]; 14 trials; n = 11 356) compared with a single form of NRT.13 Pooled analysis of trials directly comparing NRT and bupropion did not suggest a difference between the 2 types of pharmacotherapy (RR, 0.99 [95% CI, 0.91-1.09]; 10 trials; n = 8230)15; however, varenicline has been shown to be superior to both NRT (RR, 1.25 [95% CI, 1.14-1.37]; 8 trials; n = 6264)16 and bupropion (RR [bupropion vs varenicline], 0.71 [95% CI, 0.64-0.79]; 6 trials; n = 6286)15 in achieving abstinence at 6 months or more, although there are fewer trials testing these differences. There is limited evidence for the use of other antidepressants and nicotine receptor partial agonists for their effectiveness in helping people stop smoking.15,16
Compared with various controls, behavioral interventions such as in-person advice and support from clinicians26,27; individual-,28 group-,29 telephone-,34 and mobile phone–based38 support; interactive and tailored internet-based interventions41; and the use of incentives43 were associated with increased relative smoking cessation at 6 or more months (15% to 88% range of relative effects). Pooled results for all comparisons are reported in Table 2. For example, smoking cessation advice from a physician or nurse was associated with pooled RRs of 1.76 (95% CI, 1.58-1.96; 28 trials; n = 22 239)26 and 1.29 (95% CI, 1.21-1.38; 44 trials; n = 20 881),27 respectively. Behavioral support, when added to pharmacotherapy, was also associated with increased rates of smoking cessation when compared with pharmacotherapy alone (RR, 1.15 [95% CI, 1.08-1.22]; 65 trials; n = 23 331).25 There was a lack of clear benefit of motivational interviewing30; decision aids32; real-time video counseling36; print-based, nontailored self-help materials33; biomedical risk assessment45; exercise46; acupuncture48; hypnotherapy49; and systems-level interventions50,51 compared with controls; however, there was substantially less evidence related to each of these interventions, and many individual trials of these interventions showed positive effects.
There was no evidence to suggest that the benefits and harms of pharmacotherapy and behavioral interventions, alone and combined, differed when offered to specific subpopulations of adults, including those with mental health conditions, ethnic minorities, or smokeless tobacco users. Where pooled results were presented, the direction and magnitude of effects were almost identical to those seen with the broader evidence base, although very few direct comparisons between subgroups were presented. While some reviews found evidence of potential effect modification by specific intervention, population, or study design characteristics, there was no individual factor that consistently predicted greater treatment effects across reviews.
Five trials (n = 3117)80,81,90,91,93 were included that evaluated the effectiveness of using e-cigarettes to help current conventional smokers stop or reduce smoking compared with placebo or nicotine replacement therapy (eTable 3 in the Supplement). The types of e-cigarettes, nicotine content, delivery of the intervention, and additional intervention components differed across all 5 trials, as did the comparisons (eTable 3 in the Supplement). Mixed findings were reported on the effectiveness of e-cigarettes on smoking cessation at 6 to 12 months among adult smokers when compared with placebo devices or NRT (eTable 4 in the Supplement). In 2 of the 5 trials (n = 2008), smokers randomized to e-cigarettes containing nicotine (with or without the co-use of NRT) were found to have statistically significantly greater rates of abstinence than those randomized to NRT alone90 or NRT plus nonnicotine e-cigarettes91 at 6- to 12-month follow-up. In both trials, continued use of e-cigarettes was high at 6- and 12-month follow-up (approximately 3-9 months after the treatment phase), with 45% to 80% of participants still using nicotine-based e-cigarettes as opposed to approximately 9% to 40% of participants still using NRT. Another trial (n = 300) compared the use of e-cigarettes (2 groups using different nicotine concentrations) with placebo at 12 months and found 11% abstinence in the nicotine-containing e-cigarette groups compared with 4% abstinence in the placebo group (P = .04), but 27% of those who quit smoking continued to use e-cigarettes at 1 year.81 The remaining 2 trials (n = 807) reported no clear difference in the rates of smoking cessation among those randomized to nicotine e-cigarettes vs placebo e-cigarettes80 or nicotine gum at 6 to 12 months’ follow-up.93
Key Question 3. What harms are associated with tobacco cessation interventions in adults?
Nine primary reviews reported adverse events related to pharmacotherapy interventions for smoking cessation in general adult populations.12-16,18-20,22 There was no association between the use of NRT, bupropion, or varenicline and serious adverse events, including major cardiovascular adverse events or serious neuropsychiatric events, as compared with placebo or nondrug control groups. Few reviews on behavioral interventions captured information on potential harms, and none suggested serious adverse events that arose. Nine trials reported on the potential short-term harms of e-cigarette use for cessation; none suggested relatively higher rates of serious adverse events.80-84,86,90,91,93
Evidence for Pregnant Women
Based on a primary literature review of 64 full-text articles, 7 RCTs (n = 2285) (reported in 12 publications)98-109 that evaluated the use of NRT among pregnant women were included (eTable 5 in the Supplement). Additionally, 5 large observational studies (n = 1 293 379) (reported in 6 publications)110-115 were included that reported on the harms of NRT, bupropion, or varenicline use (eFigure 3 in the Supplement).
Using the overview of reviews approach, 5 reviews were identified that addressed the benefits and harms of behavioral interventions for supporting women to stop smoking during pregnancy (Table 1).43,53-56 A 2017 Cochrane review included the most comprehensive evidence synthesis of tobacco cessation behavioral support interventions for pregnant women and was used as the basis for the findings presented here.54 The other identified reviews were mostly duplicative and the results were entirely consistent with the Cochrane review.
No studies were identified that addressed the benefits or harms of the use of e-cigarettes to help pregnant women quit smoking.
Health Benefits of Interventions
Key Question 1. Do tobacco cessation interventions improve mortality, morbidity, and other health outcomes in pregnant women who currently use tobacco?
All 7 included RCTs (n = 2285) were designed to test the effectiveness of NRT on smoking cessation and reported infant, child, and maternal health.98,99,102,105-107,109 Five placebo-controlled trials reported on preterm birth (delivery at <37 weeks’ gestation).98,99,105,106,109 The most recent study, conducted in 2017, reported a statistically significant lower incidence of preterm delivery among those in the NRT inhaler group (3/67 [4.5%]) compared with the placebo group (10/67 [14.9%]) (P = .03) after controlling for history of preterm birth.106 Within the other trials, 1 (n = 403) reported similar numbers of women with preterm birth in the NRT and placebo groups (14.0% vs 13.5%, respectively),98 2 (n = 1301) reported only slightly fewer women with preterm birth in the NRT group,99,109 and the study with the fewest patients (n = 194) reported reduced incidence of preterm birth with NRT compared with placebo (RR, 0.39 [95% CI, 0.17-0.91]).105 The 3 placebo-controlled trials that did not report statistically significant differences had larger samples and estimated effects closer to null, with RRs ranging from 0.85 to 1.04.98,99,109 Two trials without placebo controls were imprecise (very wide CIs) and estimated effects in opposite directions.102,107
All 7 trials reported the association between NRT and mean birth weight.98,99,102,105-107,109 Two placebo-controlled trials found significantly higher mean birth weights among women allocated to the NRT group,105,109 and only one of these trials105 reported similar effect for the proportion of infants categorized as having low birth weight. The 2 largest, good-quality, placebo-controlled trials of NRT patch interventions (n = 403 and n = 1051) did not find evidence of increased infant birth weight with NRT treatment.98,99
One hundred two RCTs were included in a 2017 review that addressed the effects of behavioral smoking cessation interventions during pregnancy on smoking behavior and perinatal health outcomes.54 Of the 102 included trials, 19 study groups reported rates of preterm birth (<37 weeks’ gestation), 26 study groups reported mean birth weight, and 17 groups reported rates of low-birth-weight infants (<2500 g).54 Other, less commonly reported data included stillbirths (8 trials), perinatal deaths (4 trials), and neonatal deaths (5 trials) (results related to these outcomes are included in the full report).
Of the 19 trials reporting the effects of a behavioral intervention on preterm birth (less than 37 weeks’ gestation), results were mixed, although the majority reported a reduced risk of preterm birth among women within the behavioral interventions vs control groups.54 The review’s meta-analysis of these trials found no significant association with behavioral interventions compared with controls on rates of preterm birth (RR, 0.93 [95% CI 0.77-1.11]; 19 trials; n = 9222) (eTable 6 in the Supplement). When all 26 studies that reported mean birth weight were combined, there was evidence that behavioral smoking cessation interventions were associated with a higher mean birth weight (55.60 g, compared with usual care control interventions; mean difference, 55.60 g [95% CI, 29.82-81.38]; 26 trials; n = 11 338) (eTable 6 in the Supplement).54 A pooled analysis of 18 RCTs also found a 17% risk reduction for delivery of a low-birth-weight infant (<2500 g) (RR, 0.83 [95% CI, 072-0.94]; 18 trials; n = 9402) (eTable 6 in the Supplement).
Cessation Benefits of Interventions
Key Question 2. Do tobacco cessation interventions increase tobacco abstinence in pregnant women who currently use tobacco?
There was no evidence of differences in rates of smoking cessation among pregnant women randomized to NRT vs placebo or no intervention within the included trials. Meta-analysis of 5 placebo-controlled trials found a pooled RR of 1.11 (95% CI, 0.79-1.56]; n = 2033) for NRT vs placebo (eFigure 4 in the Supplement).98,99,105,106,109 Quit rates in these trials ranged from 5% to 28% in the intervention groups and 5% to 25% in the control groups (mean, 11.8% vs 10.6%). The results of the 2 smaller trials with no treatment controls102,107 were not statistically significant, and estimates of efficacy were greater than for the placebo-controlled trials.
Within the Cochrane review on behavioral interventions among pregnant women, of the 120 study groups included in the review, 97 groups reported the primary outcome measure of smoking abstinence in late pregnancy, up to and including the period of hospitalization for birth.54 Pooled analyses of all behavioral interventions, regardless of type of behavioral support and including self-reported outcomes, indicated a statistically significant association with smoking cessation in late pregnancy when compared with usual care or a minimal intervention (RR, 1.35 [95% CI, 1.23-1.48]; 97 trials; n = 26 637) (eTable 7 in the Supplement). The results were similarly associated with a beneficial effect when restricted to trials comparing counseling with usual care (RR, 1.44 [95% CI, 1.19-1.73]; 30 trials; n = 12 432). There was some evidence that the positive association of behavioral interventions on smoking cessation in late pregnancy continued into the postpartum period, up until approximately 18 months postpartum. For instance, in an examination of counseling interventions compared with usual care, the average RR was 1.59 (95% CI, 1.26-2.01; 11 trials) at 0 to 5 months postpartum, 1.33 (95% CI, 1.00-1.77; 6 trials) at 6 to 11 months postpartum, and 2.20 (95% CI, 1.23-3.96; 2 trials) at 12 to 17 months.54
Key Question 3. What harms are associated with tobacco cessation interventions in pregnant women?
There was no evidence of perinatal harms related to NRT use among pregnant women, but data for assessing rare harms were very limited.98,99,102,105-107,109 Two larger trials reported stillbirths and congenital malformations and reported few events and no differences in the outcome between study groups.98,99 Trials reporting miscarriage98,99,106 and neonatal deaths98,99,105 reported few events and no difference between study groups. One trial provided extended follow-up and did not find differences in longer-term developmental or respiratory harms associated with NRT use during pregnancy.101 Evidence from 5 large cohort studies did not find differences in stillbirth, birth outcomes, or any congenital anomaly for infants born to mothers with exposure to NRT, bupropion, or varenicline vs those unexposed to medications but whose mothers smoked.110-115 Behavioral smoking cessation interventions were found to have minimal adverse effects.54
This evidence review evaluated interventions for tobacco cessation in adults; the evidence is summarized in Table 3. The results are generally consistent with the conclusions of the 2020 Surgeon General’s report on smoking cessation.2 There is moderate- to high-certainty evidence that all 7 US Food and Drug Administration–approved medications for smoking cessation, a variety of behavioral support and counseling approaches, and the combination of pharmacotherapy plus behavioral support—all interventions that may be readily available to primary care patients and clinicians—can significantly increase the rate of smoking cessation among adults at 6 months and longer compared with usual care or brief self-help materials. Treatment effects appear to be comparable in a range of populations, settings, and types of behavioral support. Furthermore, despite adding nearly 5 more years of research since the previous review,5,6 the effect estimates for each pooled comparison have been remarkably stable for at least the past 3 decades.
Nevertheless, various questions about tobacco cessation interventions have not yet been answered. Evidence is still needed to compare different forms, doses, and durations of drugs; to compare drugs with one another; to evaluate remotely delivered interventions vs minimal support; and to test interventions in special populations for which the effectiveness may differ from that in the general population (eg, pregnant women, persons with current severe mental illness, those with physical disabilities, nondaily and intermittent smokers), including direct subgroup comparisons.
Evidence on the potential benefits and harms of pharmacotherapy for smoking cessation during pregnancy is limited, with few placebo-controlled trials and limited power for detecting both potential benefits and harms (Table 3). In contrast to the findings in this review, a recent Cochrane review concluded that there was low-quality evidence suggesting that NRT may be more effective than placebo and nonplacebo controls.117 There was unclear evidence of an association when limited to only placebo-controlled trials,117 however, a finding similar to this review. Careful collection of adverse events information, including long-term consequences of stop-smoking medications, is important in future trials, and data on adherence to medications and levels of nicotine exposure from NRT relative to what occurs with smoking would also be valuable.
In contrast to the robust evidence on pharmacotherapy and behavioral interventions for smoking cessation, evidence on the use of e-cigarettes as an intervention to quit conventional smoking is lacking (Table 3). No studies on the use of e-cigarettes as tobacco cessation interventions reported health outcomes, and few trials reported on the potential adverse events of e-cigarette use when used in atttempts to quit smoking. This is particularly concerning given the apparent longer-term use of e-cigarettes for cessation compared to pharmacotherapy in addition to the recent outbreak of e-cigarette, or vaping, product use–associated lung injury.118 Furthermore, there is lack of long-term epidemiologic studies and large clinical trials examining the associations between e-cigarette use and morbidity and mortality, especially in the long term.119
Although this review was scoped to include interventions focused on quitting any tobacco product, most published trials have targeted (and reported) quitting combustible cigarette use. More research is needed on interventions to help people quit other tobacco products such as cigars, smokeless tobacco, and e-cigarettes. Given the high prevalence of dual use of combustible and electronic cigarettes,120 there is a need for research on interventions to help dual users of conventional cigarettes and e-cigarettes quit both products, as well as research on potential relapse back to cigarette use among former smokers who use e-cigarettes.
The primary limitation of the evidence report relates to the overview of reviews approach. The comprehensiveness of the overview of reviews is inevitably limited by the recency and quality of the source reviews. Although most of the reviews included evidence at least through 2015, there may be evidence on specific population and intervention subsets that has been published after each review’s last search date. If this occurred, the respective bodies of evidence may not reflect these newer studies. Given the consistency of the effects within each group over time, however, it appears unlikely that any new trials, regardless of their sample size and effect estimates, would have substantial bearing on the overall results of this overview of reviews.
There is strong evidence that a range of pharmacologic and behavioral interventions, both individually and in combination, are effective in increasing smoking cessation in nonpregnant adults. In pregnancy, behavioral interventions are effective for smoking cessation, but data are limited on the use of pharmacotherapy for smoking cessation. Data on the effectiveness and safety of electronic cigarettes for smoking cessation among adults are also limited and results are inconsistent.
Corresponding Author: Carrie D. Patnode, PhD, MPH, Kaiser Permanente Evidence-based Practice Center, Center for Health Research, Kaiser Permanente Northwest, 3800 N Interstate Ave, Portland, OR 97227 (carrie.d.patnode@kpchr.org).
Accepted for Publication: December 4, 2020.
Author Contributions: Dr Patnode had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Concept and design: Patnode, Henderson, Coppola, Melnikow.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Patnode, Coppola.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Patnode.
Administrative, technical, or material support: Henderson, Coppola, Melnikow, Durbin, Thomas.
Supervision: Patnode, Henderson, Melnikow.
Conflict of Interest Disclosures: None reported.
Funding/Support: This research was funded under contract HHSA-290-2015-00007-I-EPC5, Task Order 5, from the Agency for Healthcare Research and Quality (AHRQ), US Department of Health and Human Services, under a contract to support the US Preventive Services Task Force (USPSTF).
Role of the Funder/Sponsor: Investigators worked with USPSTF members and AHRQ staff to develop the scope, analytic framework, and key questions for this review. AHRQ had no role in study selection, quality assessment, or synthesis. AHRQ staff provided project oversight, reviewed the report to ensure that the analysis met methodological standards, and distributed the draft for peer review. Otherwise, AHRQ had no role in the conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript findings. The opinions expressed in this document are those of the authors and do not reflect the official position of AHRQ or the US Department of Health and Human Services.
Additional Contributions: We gratefully acknowledge the following individuals for their contributions to this project: Tina Fan, MD, MPH (AHRQ); current and former members of the US Preventive Services Task Force who contributed to topic deliberations; Evidence-based Practice Center staff members Todd Hannon, MLS, and Katherine Essick, BS (Kaiser Permanente Center for Health Research), for technical and editorial assistance. USPSTF members, peer reviewers, and those commenting on behalf of partner organizations did not receive financial compensation for their contributions.
Additional Information: A draft version of this evidence report underwent external peer review from 6 content experts (Brian King, PhD, MPH [Centers for Disease Control and Prevention], Janet Wright, MD [Office of the Surgeon General], Nicola Lindson, BSc, MSc, CPsychol, PhD [University of Oxford], Stephen Fortmann, MD [Kaiser Permanente Center for Health Research], Nancy Rigotti, MD [Harvard Medical School], and Michele Levine, PhD [University of Pittsburgh]) and 3 federal partners (Centers for Disease Control and Prevention, National Institutes of Health, and US Food and Drug Administration). Comments were presented to the USPSTF during its deliberation of the evidence and were considered in preparing the final evidence review.
Editorial Disclaimer: This evidence report is presented as a document in support of the accompanying USPSTF recommendation statement. It did not undergo additional peer review after submission to JAMA.
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