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Aims This study aims to compare biomarkers of potential harm between people switching from smoking combustible cigarettes (CC) completely to electronic cigarettes (EC), continuing to smoke CC, using both EC and CC (dual users) and using neither (abstainers), based on behaviour during EC intervention studies. Design Secondary analysis following systematic review, incorporating inverse variance random-effects meta-analysis and effect direction plots. Setting This study was conducted in Greece, Italy, Poland, the United Kingdom and the United States. Participants A total of 1299 adults smoking CC (nine studies) and provided EC. Measurements Measuremens were conducted using carbon monoxide (CO) and 26 other biomarkers. Findings In pooled analyses, exhaled CO (eCO) was lower in EC versus EC + CC [mean difference (MD) = −4.40 parts per million (p.p.m.), 95% confidence interval (CI) = −12.04 to 3.24, two studies] and CC (MD = −9.57 p.p.m., 95% CI = −17.30 to −1.83, three studies). eCO was lower in dual users versus CC only (MD = −1.91 p.p.m., 95% CI = −3.38 to −0.45, two studies). Magnitude rather than direction of effect drove substantial statistical heterogeneity. Effect direction plots were used for other biomarkers. Comparing EC with CC, 12 of 13 biomarkers were significantly lower in EC users, with no difference for the 13th. Comparing EC with dual users, 12 of the 25 biomarkers were lower for EC, and five were lower for dual use. For the remaining eight measures, single studies did not detect statistically significant differences, or the multiple studies contributing to the outcome had inconsistent results. Only one study provided data comparing dual use with CC; of the 13 biomarkers measured, 12 were significantly lower in the dual use group, with no statistically significant difference detected for the 13th. Only one study provided data on abstainers. Conclusions Switching from smoking to vaping or dual use appears to reduce levels of biomarkers of potential harm significantly.

Background Electronic cigarettes (ECs) are handheld electronic vaping devices which produce an aerosol formed by heating an e‐liquid. Some people who smoke use ECs to stop or reduce smoking, but some organizations, advocacy groups and policymakers have discouraged this, citing lack of evidence of efficacy and safety. People who smoke, healthcare providers and regulators want to know if ECs can help people quit and if they are safe to use for this purpose. This is an update conducted as part of a living systematic review. Objectives To examine the effectiveness, tolerability, and safety of using electronic cigarettes (ECs) to help people who smoke tobacco achieve long‐term smoking abstinence. Search methods We searched the Cochrane Tobacco Addiction Group's Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 May 2021, and reference‐checked and contacted study authors. We screened abstracts from the Society for Research on Nicotine and Tobacco (SRNT) 2021 Annual Meeting. Selection criteria We included randomized controlled trials (RCTs) and randomized cross‐over trials, in which people who smoke were randomized to an EC or control condition. We also included uncontrolled intervention studies in which all participants received an EC intervention. Studies had to report abstinence from cigarettes at six months or longer or data on safety markers at one week or longer, or both. Data collection and analysis We followed standard Cochrane methods for screening and data extraction. Our primary outcome measures were abstinence from smoking after at least six months follow‐up, adverse events (AEs), and serious adverse events (SAEs). Secondary outcomes included the proportion of people still using study product (EC or pharmacotherapy) at six or more months after randomization or starting EC use, changes in carbon monoxide (CO), blood pressure (BP), heart rate, arterial oxygen saturation, lung function, and levels of carcinogens or toxicants or both. We used a fixed‐effect Mantel‐Haenszel model to calculate risk ratios (RRs) with a 95% confidence interval (CI) for dichotomous outcomes. For continuous outcomes, we calculated mean differences. Where appropriate, we pooled data in meta‐analyses. Main results We included 61 completed studies, representing 16,759 participants, of which 34 were RCTs. Five of the 61 included studies were new to this review update. Of the included studies, we rated seven (all contributing to our main comparisons) at low risk of bias overall, 42 at high risk overall (including all non‐randomized studies), and the remainder at unclear risk. There was moderate‐certainty evidence, limited by imprecision, that quit rates were higher in people randomized to nicotine EC than in those randomized to nicotine replacement therapy (NRT) (risk ratio (RR) 1.53, 95% confidence interval (CI) 1.21 to 1.93; I2 = 0%; 4 studies, 1924 participants). In absolute terms, this might translate to an additional three quitters per 100 (95% CI 1 to 6). There was low‐certainty evidence (limited by very serious imprecision) that the rate of occurrence of AEs was similar (RR 0.98, 95% CI 0.80 to 1.19; I2 = 0%; 2 studies, 485 participants). SAEs were rare, but there was insufficient evidence to determine whether rates differed between groups due to very serious imprecision (RR 1.44, 95% CI 0.94 to 2.19: I2 = 0; 3 studies, 1183 participants). There was moderate‐certainty evidence, again limited by imprecision, that quit rates were higher in people randomized to nicotine EC than to non‐nicotine EC (RR 1.94, 95% CI 1.21 to 3.13; I2 = 0%; 5 studies, 1447 participants). In absolute terms, this might lead to an additional seven quitters per 100 (95% CI 2 to 16). There was moderate‐certainty evidence of no difference in the rate of AEs between these groups (RR 1.01, 95% CI 0.91 to 1.11; I2 = 0%; 3 studies, 601 participants). There was insufficient evidence to determine whether rates of SAEs differed between groups, due to very serious imprecision (RR 0.95, 95% CI 0.52 to 1.72; I2 = 0; 6 studies, 1033 participants). Compared to behavioural support only/no support, quit rates were higher for participants randomized to nicotine EC (RR 2.61, 95% CI 1.44 to 4.74; I2 = 0%; 6 studies, 2886 participants). In absolute terms this represents an additional six quitters per 100 (95% CI 2 to 15). However, this finding was of very low certainty, due to issues with imprecision and risk of bias. There was some evidence that non‐serious AEs were more common in people randomized to nicotine EC (RR 1.22, 95% CI 1.12 to 1.32; I2 = 41%, low certainty; 4 studies, 765 participants), and again, insufficient evidence to determine whether rates of SAEs differed between groups (RR 1.51, 95% CI 0.70 to 3.24; I2 = 0%; 7 studies, 1303 participants). Data from non‐randomized studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued use. Very few studies reported data on other outcomes or comparisons, hence evidence for these is limited, with CIs often encompassing clinically significant harm and benefit. Authors' conclusions There is moderate‐certainty evidence that ECs with nicotine increase quit rates compared to NRT and compared to ECs without nicotine. Evidence comparing nicotine EC with usual care/no treatment also suggests benefit, but is less certain. More studies are needed to confirm the effect size. Confidence intervals were for the most part wide for data on AEs, SAEs and other safety markers, with no difference in AEs between nicotine and non‐nicotine ECs. Overall incidence of SAEs was low across all study arms. We did not detect evidence of harm from nicotine EC, but longest follow‐up was two years and the number of studies was small. The main limitation of the evidence base remains imprecision due to the small number of RCTs, often with low event rates, but further RCTs are underway. To ensure the review continues to provide up‐to‐date information to decision‐makers, this review is now a living systematic review. We run searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the evidence on the relationship between the use and availability of e‐cigarettes and subsequent cigarette smoking in young people (aged 29 years or less), and whether the relationship differs by socioeconomic status, gender, or other demographic characteristics.

Hospitalization offers tobacco smokers an opportunity to quit smoking, but factors associated with abstinence from tobacco after hospital discharge are poorly understood. We analyzed data from a multisite, randomized controlled trial testing a smoking cessation intervention for 1,357 hospitalized cigarette smokers who planned to quit. Using multiple logistic regression, we assessed factors identifiable in the hospital that were independently associated with biochemically confirmed tobacco abstinence six months after discharge. Biochemically confirmed abstinence at six months (n = 218, 16%) was associated with a smoking-related primary discharge diagnosis (Adjusted Odds Ratio [AOR] = 1.98, 95% CI: 1.41–2.77), greater confidence in the ability to quit smoking (AOR = 1.31, 95% CI: 1.07–1.60), and stronger intention to quit (plan to quit after discharge vs try to quit; AOR=1.68, 95% CI: 1.19–2.38). In conclusion, smokers hospitalized with a tobacco-related illness and those with greater confidence and intention to quit after discharge are more likely to sustain abstinence in the long term. Hospital clinicians’ efforts to promote smoking cessation should target smokers’ confidence and motivation to quit.

Many patients with cancer use electronic cigarettes (e‐cigarettes), yet little is known about patterns and reasons for use. Using cross‐sectional baseline data from a randomized controlled trial, we aimed to describe prevalence and correlates of e‐cigarette use, frequency of use, and reasons for use among smokers recently diagnosed with cancer. Participants (n = 302) included adults (age ≥18 years) recently diagnosed with varied cancer types who smoked ≥1 cigarette within the past 30‐d from two US academic medical centers. Participants reported ever and current e‐cigarette use, and current e‐cigarette users reported days of e‐cigarette use and the main reason for use. We compared current, former, and never e‐cigarette users by sociodemographics, cancer type, medical comorbidities, smoking behaviors, attitudes, and emotional symptoms, and described use among current e‐cigarette users. Of smokers recently diagnosed with cancer, 49% (n = 149) reported ever e‐cigarette use and 19% (n = 56) reported current use. Of current e‐cigarette users, 29% (n = 16) reported daily use. Current e‐cigarette users did not differ from former and never e‐cigarette users by cancer type, smoking behaviors, or emotional symptoms. Women were more likely to be current users than never users, and current e‐cigarette users had less education than former users. Most current e‐cigarette users reported using them to help quit smoking (75%). One in five smokers with cancer report current e‐cigarette use, but most are not using e‐cigarettes daily. The majority report using e‐cigarettes to quit smoking. E‐cigarette use by patients with cancer appears to reflect a desire to quit smoking.

Aims To estimate the prevalence and predictors of failed biochemical verification of self-reported abstinence among participants enrolled in trials of hospital-initiated smoking cessation interventions. Design Comparison of characteristics between participants who verified and those who failed to verify self-reported abstinence. Settings Multi-site randomized clinical trials conducted between 2010 and 2014 in hospitals throughout the United States. Participants Recently hospitalized smokers who reported tobacco abstinence 6 months post-randomization and provided a saliva sample for verification purposes (n = 822). Measurements Outcomes were salivary cotinine-verified smoking abstinence at 10 and 15 ng/ml cut-points. Predictors and correlates included participant demographics and tobacco use; hospital diagnoses and treatment; and study characteristics collected via surveys and electronic medical records. Findings Usable samples were returned by 69.8% of the 1178 eligible trial participants who reported 7-day point prevalence abstinence. The proportion of participants verified as quit was 57.8% [95% confidence interval (CI) = 54.4, 61.2; 10 ng/ml cut-off] or 60.6% (95% CI = 57.2, 63.9; 15 ng/ml). Factors associated independently with verification at 10 ng/ml were education beyond high school education [odds ratio (OR) = 1.51; 95% CI = 1.07, 2.11], continuous abstinence since hospitalization (OR = 2.82; 95% CI = 2.02, 3.94), mailed versus in-person sample (OR = 3.20; 95% CI = 1.96, 5.21) and race. African American participants were less likely to verify abstinence than white participants (OR = 0.64; 95% CI = 0.44, 0.93). Findings were similar for verification at 15 ng/ml. Verification rates did not differ by treatment group. Conclusions In the United States, high rates (40%) of recently hospitalized smokers enrolled in smoking cessation trials fail biochemical verification of their self-reported abstinence.

Aims We determined whether or not homelessness is associated with cigarette smoking independent of other socio-economic measures and behavioral health factors, and whether homeless smokers differ from non-homeless smokers in their desire to quit. Design, setting and participants We analyzed data from 2678 adult respondents to the 2009 Health Center Patient Survey, a nationally representative cross-sectional survey of homeless and non-homeless individuals using US federally funded community health centers. Measurements We used multivariable logistic regression to examine the association between homelessness and (i) current cigarette smoking among all adults, and (ii) past-year desire to quit among current smokers, adjusting for demographic, socio-economic and behavioral health characteristics. Findings Adults with any history of homelessness were more likely than never homeless respondents to be current smokers (57 versus 27%, P

BACKGROUND: The National Lung Screening Trial (NLST) research team reported reduced lung cancer mortality among current and former smokers with a minimum 30 pack-year history who were screened with spiral computed tomography scans compared with chest x-rays. The objectives of the current study were to examine, at 1-year follow-up: 1) risk perceptions of lung cancer and smoking-related diseases and behavior change determinants, 2) whether changes in risk perceptions differed by baseline screening result; and 3) whether changes in risk perceptions affected smoking behavior. METHODS: A 25-item risk perception questionnaire was administered to a subset of participants at 8 American College of Radiology Imaging Network/NLST sites before initial and 1-year follow-up screens. Items assessed risk perceptions of lung cancer and smoking-related diseases, cognitive and emotional determinants of behavior change, and knowledge of smoking risks. RESULTS: Among 430 NLST participants (mean age, 61.0 years; 55.6% men; 91.9% white), half were current smokers at baseline. Overall, risk perceptions and associated cognitive and emotional determinants of behavior change did not change significantly from prescreen trial enrollment to 1-year follow-up and did not differ significantly by screening test result. Changes in risk perceptions were not associated with changes in smoking status (9.7% of participants quit, and 6.6% relapsed) at 1-year follow-up. CONCLUSIONS: Lung screening did not change participants' risk perceptions of lung cancer or smoking-related disease. A negative screening test, which was the most common screening result, did not appear to decrease risk perceptions nor provide false reassurance to smokers. Cancer 2013. © 2012 American Cancer Society.

BACKGROUND: Continued smoking after a cancer diagnosis may adversely affect treatment effectiveness, subsequent cancer risk, and survival. The prevalence of continued smoking after cancer diagnosis is understudied. METHODS: In the multi-regional Cancer Care Outcomes Research and Surveillance cohort (lung cancer [N = 2456], colorectal cancer [N = 3063]), the authors examined smoking rates at diagnosis and 5 months after diagnosis and also study factors associated with continued smoking. RESULTS: Overall, 90.2% of patients with lung cancer and 54.8% of patients with colorectal cancer reported ever smoking. At diagnosis, 38.7% of patients with lung cancer and 13.7% of patients with colorectal cancer were smoking; whereas, 5 months after diagnosis, 14.2% of patients with lung cancer and 9.0% of patients with colorectal cancer were smoking. Factors that were associated independently with continued smoking among patients with nonmetastatic lung cancer were coverage by Medicare, other public/unspecified insurance, not receiving chemotherapy, not undergoing surgery, prior cardiovascular disease, lower body mass index, lower emotional support, and higher daily ever-smoking rates (all P < .05). Factors that were associated independently with continued smoking among patients with nonmetastatic colorectal cancer were male sex, high school education, being uninsured, not undergoing surgery, and higher daily ever-smoking rates (all P < .05). CONCLUSIONS: After diagnosis, a substantial minority of patients with lung and colorectal cancers continued smoking. Patients with lung cancer had higher rates of smoking at diagnosis and after diagnosis; whereas patients with colorectal cancer were less likely to quit smoking after diagnosis. Factors that were associated with continued smoking differed between lung and colorectal cancer patients. Future smoking-cessation efforts should examine differences by cancer type, particularly when comparing cancers for which smoking is a well established risk factor versus cancers for which it is not. Cancer 2012;118: 3153–64. © 2012 American Cancer Society.

The Framework Convention on Tobacco Control (FCTC) asks countries to develop and disseminate comprehensive evidence-based guidelines and promote adequate treatment for tobacco dependence, yet to date no summary of the content of existing guidelines exists. This paper describes the national tobacco dependence treatment guidelines of 31 countries.A questionnaire on tobacco dependence treatment guidelines was sent by e-mail to a convenience sample of contacts working in tobacco control in 31 countries in 2007. Completed questionnaires were received from respondents in all 31 countries. During the course of these enquiries we also made contact with people in 14 countries that did not have treatment guidelines and sent them a short questionnaire asking about their plans to produce guidelines.The survey instrument was a 17-item questionnaire asking the following key questions: do the guidelines recommend brief interventions, intensive behavioural support, medications; which medications; do the guidelines apply to the whole health-care system and all professionals; do they refer explicitly to the Cochrane database; are they based on another country's guidelines; are they national or more local; are they endorsed formally by government; did they undergo peer review; who funded them; where were they published; do they include evidence on cost effectiveness of treatment?According to respondents, all their countries' guidelines recommended brief advice, intensive behavioural support and nicotine replacement therapy (NRT); 84% recommended bupropion; 19% recommended varenicline; and 35% recommended telephone quitlines. Nearly half (48%) included cost-effectiveness evidence. Seventy-one per cent were supported formally by their government and 65% were supported financially by the government. Most (84%) used the Cochrane reviews as a source of evidence, 84% underwent a peer review process and 55% were based on the guidelines of other countries, most often the United States and England.Overall, the guidelines reviewed followed the evidence base closely, recommending brief interventions, intensive behavioural support and NRT, and most recommended bupropion. Varenicline was not on the market in most of the countries in this survey when their guidelines were written, illustrating the need for guidelines to be updated periodically. None recommended interventions not proven to be effective, and some recommended explicitly against specific interventions (for lack of evidence). Most were peer-reviewed, many through lengthy and rigorous procedures, and most were endorsed or supported formally by their governments. Some countries that did not have guidelines expressed a need for technical support, emphasizing the need for countries to share experience, something the FCTC process is well placed to support.

Aims To report progress among Parties to the World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) in developing national tobacco treatment guidelines in accordance with FCTC Article 14 guideline recommendations. Design Cross-sectional study. Setting Electronic survey from December 2011 to August 2012; participants were asked to complete either an online or attached Microsoft Word questionnaire. Participants One hundred and sixty-three of the 173 Parties to the FCTC at the time of our survey. Measurements The 51-item questionnaire contained 30 items specifically on guidelines. Questions covered the areas of guidelines writing process, content, key recommendations and other characteristics. Findings One hundred and twenty-one countries (73%) responded. Fifty-three countries (44%) had guidelines, ranging from 75% among high-income countries to 11% among low-income countries. Nearly all guidelines recommended brief advice (93%), intensive specialist support (93%) and medications (96%), while 66% recommended quitlines. Fifty-seven percent had a dissemination strategy, 76% stated funding source and 68% had professional endorsement. Conclusion Fewer than half of the Parties to the WHO FCTC have developed national tobacco treatment guidelines, but, where guidelines exist, they broadly follow FCTC Article 14 guideline recommendations.