The Association Between Tobacco Use and Risk of COVID-19 Infection and Clinical Outcomes in Sweden: A Population-Based Study.

Background: The association between tobacco use and COVID-19 is controversial. During the early course of the pandemic, limited testing prevented studying a wide spectrum of clinical manifestations. Objective: To examine the potential causal association between tobacco use and COVID-19 during the second wave (1 October 2020-30 June 2021) of the pandemic in Stockholm, Sweden. Methods: A population-based cohort study was conducted in the Stockholm region of Sweden, with information on tobacco use collected prior to the pandemic. Adjusted relative risks (RR) of COVID-19 and 95% confidence intervals (CI) were calculated, contrasting current smokers and snus users to non-users of tobacco. Results: Compared with non-users of tobacco, current smokers had a lower risk of COVID-19 (RR 0.78, 95% CI = 0.75-0.81) and of hospitalisation for the disease. Current snus users had a higher risk of COVID-19. Heavy smokers and snus users had longer hospital stays than non-users of tobacco. Conclusion: Tobacco use may have a different impact on the risk of being infected with SARS-CoV-2 and the risk of developing severe clinical manifestations. Further research is needed to determine the underlying mechanisms.

Current tobacco use and COVID-19 diagnoses in a cohort of adult clients of public dental clinics in Sweden.

Smoking has been linked with both increased and decreased risk of COVID-19, prompting the hypothesis of a protective role of nicotine in the pathogenesis of the disease. Studies of the association between use of smokeless tobacco and COVID-19 would help refining this hypothesis. We analysed data from 424,386 residents in the Stockholm Region, Sweden, with information on smoking and smokeless tobacco (snus) use prior to the pandemic obtained from dental records. Diagnoses of COVID-19 between February and October 2020 were obtained from health-care registers. We estimated the risk of receiving a diagnosis of COVID-19 for current smokers and for current snus users relative to non-users of tobacco, adjusting for potential confounders (aRR). The aRR of COVID -19 was elevated for current snus users (1.09 ;95%CI = 0.99-1.21 among men and 1.15; 95%CI = 1.00-1.33 among women). The risk for women consuming more than 1 can/day was twice as high as among non-users of tobacco. Current smoking was negatively associated with risk of COVID-19 (aRR = 0.68; 95% CI = 0.61-0.75); including hospital admission (aRR = 0.60; 95% CI = 0.47-0.76) and intensive care (aRR = 0.43; 95% CI = 0.21-0.89). The hypothesis of a protective effect of tobacco nicotine on COVID-19 was not supported by the findings. The negative association between smoking and COVID-19 remains unexplained.

Increasing Children's physical Activity by Policy (CAP) in preschools within the Stockholm region: study protocol for a pragmatic cluster-randomized controlled trial.

BACKGROUND: Systematic reviews suggest that preschool environmental/organizational changes may be effective in increasing physical activity (PA) levels of preschool children, but evidence is scarce regarding feasible, effective, and equitable interventions that can be scaled up. Specifically, it is essential to understand whether introducing a multicomponent organizational change in terms of policy in the preschool context may be beneficial for children's PA levels and concomitant health outcomes. To bridge this knowledge gap, our main aim is to examine the feasibility and effectiveness of a policy package in increasing PA levels in preschool children, using a large-scale pragmatic cluster-randomized controlled trial. METHODS: This proposed study is a pragmatic cluster-randomized controlled trial with two conditions (intervention and control with a 1:1 ratio) with preschools as clusters and the unit of randomization. We aim to recruit approximately 4000 3-5-year-old children from 90 preschools and retain more than 2800 children from 85 preschools to provide adequate statistical power for the analyses. The intervention to implement is a co-created, multicomponent policy package running for 6 months in preschools randomized to intervention. Change in accelerometer measured PA levels in children between intervention and control from pre- and post-intervention will be the primary outcome of the study, while secondary outcomes include health outcomes such as musculoskeletal fitness, psychosocial functioning, and absence due to illness in children among others. Implementation will be studied carefully using both quantitative (dose, fidelity) and qualitative (interview) methodologies. The change in primary and secondary outcomes, from pre- to post-intervention, will be analyzed with linear mixed-effect models (to allow both fixed and random effects) nested on a preschool level. DISCUSSION: This is a large-scale co-creation project involving the City of Stockholm, childcare stakeholders, preschool staff, and the research group with the potential to influence more than 30,000 preschool children within the Stockholm area. The study will add reliable evidence for the implementation of PA policies at the organizational level of preschools and clarify its potential effect on objectively measured PA and health markers in children. TRIAL REGISTRATION: ClinicalTrials.gov NCT04569578 . Prospectively registered on September 20, 2020.

Rates of asymptomatic respiratory virus infection across age groups.

Respiratory viral infections are a leading cause of disease worldwide. A variety of respiratory viruses produce infections in humans with effects ranging from asymptomatic to life-treathening. Standard surveillance systems typically only target severe infections (ED outpatients, hospitalisations, deaths) and fail to track asymptomatic or mild infections. Here we performed a large-scale community study across multiple age groups to assess the pathogenicity of 18 respiratory viruses. We enrolled 214 individuals at multiple New York City locations and tested weekly for respiratory viral pathogens, irrespective of symptom status, from fall 2016 to spring 2018. We combined these test results with participant-provided daily records of cold and flu symptoms and used this information to characterise symptom severity by virus and age category. Asymptomatic infection rates exceeded 70% for most viruses, excepting influenza and human metapneumovirus, which produced significantly more severe outcomes. Symptoms were negatively associated with infection frequency, with children displaying the lowest score among age groups. Upper respiratory manifestations were most common for all viruses, whereas systemic effects were less typical. These findings indicate a high burden of asymptomatic respiratory virus infection exists in the general population.

Effectiveness of interventions on physical activity in overweight or obese children: a systematic review and meta-analysis including studies with objectively measured outcomes.

There is no consensus on interventions to be recommended in order to promote physical activity among overweight or obese children. The objective of this review was to assess the effects on objectively measured physical activity, of interventions promoting physical activity among overweight or obese children or adolescents, compared to no intervention or to interventions without a physical activity component. Publications up to December 2015 were located through electronic searches for randomized controlled trials resulting in inclusion of 33 studies. Standardized mean differences from baseline to post-intervention and to long-term follow-up were determined for intervention and control groups and meta-analysed using random effects models. The meta-analysis showed that interventions had no effect on total physical activity of overweight and obese children, neither directly post-intervention (-0.02 [-0.15, 0.11]) nor at long-term follow-up (0.07 [-0.27, 0.40]). Separate analyses by typology of intervention (with or without physical fitness, behavioural or environmental components) showed similar results (no effect). In conclusion, there is no evidence that currently available interventions are able to increase physical activity among overweight or obese children. This questions the contribution of physical activity to the treatment of overweight and obesity in children in the studied interventions and calls for other treatment strategies.

Snus (Swedish smokeless tobacco) use and risk of stroke: pooled analyses of incidence and survival.

BACKGROUND: Snus is a moist smokeless tobacco product with high nicotine content. Its use has a short-term effect on the cardiovascular system, but the relationship between snus use and stroke is unclear. OBJECTIVE: The aim of this study was to assess the associations between use of snus and incidence of and survival after stroke, both overall and according to subtypes. METHODS: Pooled analyses of eight Swedish prospective cohort studies were conducted, including 130 485 men who never smoked. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) of incidence and death after diagnosis using Cox proportional hazard regression models and case fatality and survival using logistic regression and Kaplan-Meier methods, respectively. RESULTS: No associations were observed between the use of snus and the risk of overall stroke (HR 1.04, 95% CI 0.92-1.17) or of any of the stroke subtypes. The odds ratio (OR) of 28-day case fatality was 1.42 (95% CI 0.99-2.04) amongst users of snus who had experienced a stroke, and the HR of death during the follow-up period was 1.32 (95% CI 1.08-1.61). CONCLUSION: Use of snus was not associated with the risk of stroke. Hence, nicotine is unlikely to contribute importantly to the pathophysiology of stroke. However, case fatality was increased in snus users, compared with nonusers, but further studies are needed to determine any possible causal mechanisms.

Effect of Swedish snuff (snus) on preterm birth.

OBJECTIVE: To compare the effects of Swedish snuff and cigarette smoking on risks of preterm birth. DESIGN: Population-based cohort study. SETTING: Sweden. POPULATION: All live, singleton births in Sweden 1999-2006. METHODS: Odds ratios (OR) with 95% confidence intervals (CI) were used to estimate relative risks for preterm birth in snuff users (n = 7607), light smokers (1-9 cigarettes/day; n = 41 436) and heavy smokers (ten or more cigarettes/day; n = 16 951) using non-tobacco users (n = 503 957) as reference. MAIN OUTCOME MEASURES: Very (<32 weeks) and moderately (32-36 weeks) preterm birth. RESULTS: Compared with non-tobacco users, snuff users had increased risks of both very (adjusted OR 1.38; 95% CI 1.04-1.83) and moderately (adjusted OR 1.25; 95% CI 1.12-1.40) preterm birth. Compared with non-tobacco users, light smokers had increased risks of both very (adjusted OR 1.60; 95% CI 1.42-1.81) and moderately (adjusted OR: 1.18; 95% CI: 1.12-1.24) preterm birth, and heavy smokers had even higher risks. Among smokers, but not among snuff users, the risk was more pronounced for spontaneous than induced preterm birth. CONCLUSIONS: The use of Swedish snuff was associated with increased risks of very and moderately preterm birth with both spontaneous and induced onsets. Swedish snuff is not a safe alternative to cigarette smoking during pregnancy.

Use of snus and risk for cardiovascular disease: results from the Swedish Twin Registry.

OBJECTIVE: To study the association between snus use and the risk for cardiovascular disease, i.e. ischemic heart disease and stroke. DESIGN: Cohort study. SETTING: Sweden. SUBJECTS: Sixteen thousand six hundred and forty-two male Swedish twins participating in the Screening Across the Lifespan Twin Study, conducted in 1998- 2002, were followed for incident cardiovascular disease. Participants were without a history of cardiovascular disease at baseline and incident cases were identified via the Swedish Cause of Death Register and Hospital Discharge Register. RESULTS: Overall, there was no association between use of snus and risk for cardiovascular disease. Current snus users, without a smoking history, had a relative risk of 1.00 (95% confidence interval 0.69-1.46) for cardiovascular disease as compared to non users. Corresponding relative risks for ischemic heart disease and stroke were 0.85 (95% confidence interval 0.51-1.41) and 1.18 (95% confidence interval 0.67-2.08), respectively. In smoking adjusted models, risk estimates for ischemic heart disease in relation to snus use were all close to unity regardless of timing or intensity of snus use. However, current heavy snus users (consuming more than four cans week(-1)) had a relative risk for stroke of 1.75 (95% confidence interval 0.95-3.21). CONCLUSION: These data do not support any strong association between snus use and risk for cardiovascular disease.

Is universal prevention against youths' substance misuse really universal? Gender-specific effects in the EU-Dap school-based prevention trial.

BACKGROUND: Studies of effectiveness of school-based prevention of substance misuse have generally overlooked gender differences. The purpose of this work was to analyse gender differences in the effectiveness of a new European school-based curriculum for prevention of substance misuse among adolescents. METHODS: The European Drug Abuse Prevention (EU-Dap) trial took place in seven European countries during the school year 2004-05. Schools were randomly assigned to either a control group or a 12-session standardised curriculum ("Unplugged") based on a comprehensive social influence model. The analytical sample consisted of 6359 students (3324 boys and 3035 girls). The use of cigarettes, alcohol and illicit drugs, adolescents' knowledge and opinions about substances, as well as social and personal skills were investigated through a self-completed anonymous questionnaire administered at enrollment and 3 months after the end of the programme. Adjusted Prevalence Odds Ratios were calculated as the measure of association between the intervention and behavioural outcomes using multilevel regression modelling. RESULTS: At enrollment, boys were more likely than girls to have used cannabis and illicit drugs, whereas girls had a higher prevalence of cigarette smoking. At the follow-up survey, a significant association between the programme and a lower prevalence of all behavioural outcomes was found among boys, but not among girls. Age and self-esteem emerged as possible modifiers of these gender differences, but effects were not statistically significant. CONCLUSIONS: Comprehensive social influence school curricula against substance misuse in adolescence may perform differently among girls and boys, owing to developmental and personality factors.

Quitting cigarettes completely or switching to smokeless tobacco: do US data replicate the Swedish results?

BACKGROUND: Swedish male smokers are more likely than female smokers to switch to smokeless tobacco (snus) and males' smoking cessation rate is higher than that of females. These results have fuelled international debate over promoting smokeless tobacco for harm reduction. This study examines whether similar results emerge in the United States, one of few other western countries where smokeless tobacco has long been widely available. METHODS: US DATA SOURCE: national sample in Tobacco Use Supplement to Current Population Survey, 2002, with 1-year follow-up in 2003. Analyses included adult self-respondents in this longitudinal sample (n = 15,056). Population-weighted rates of quitting smoking and switching to smokeless tobacco were computed for the 1-year period. RESULTS: Among US men, few current smokers switched to smokeless tobacco (0.3% in 12 months). Few former smokers turned to smokeless tobacco (1.7%). Switching between cigarettes and smokeless tobacco, infrequent among current tobacco users (<4%), was more often from smokeless to smoking. Men quit smokeless tobacco at three times the rate of quitting cigarettes (38.8% vs 11.6%, p<0.001). Overall, US men have no advantage over women in quitting smoking (11.7% vs 12.4%, p = 0.65), even though men are far likelier to use smokeless tobacco. CONCLUSION: The Swedish results are not replicated in the United States. Both male and female US smokers appear to have higher quit rates for smoking than have their Swedish counterparts, despite greater use of smokeless tobacco in Sweden. Promoting smokeless tobacco for harm reduction in countries with ongoing tobacco control programmes may not result in any positive population effect on smoking cessation.

[Axillary lymphadenitis due to Corynebacterium pseudotuberculosis in a 63-year-old patient]. / Lymphadénite axillaire à Corynebacterium pseudotuberculosis chez une patiente de 63 ans.

A 63-year-old woman living in a rural area presented in 2004 with a granulomatous necrotizing axillary lymphadenitis caused by Corynebacterium pseudotuberculosis, a Gram positive bacillus belonging to the group of Corynebacterium diphtheriae, which is found primarily in animal infections. In the human being, around 30 cases of infection due to C. pseudotuberculosis have been described, mainly among people working in contact with infected animals. For this reason, this infection, which induces exclusively lymphadenitis and abscesses with granulomatous necrotizing lesions, should be regarded as an occupational disease. In this patient, due to ignorance of the disease, this bacterium was considered to be merely saprophytic. The first treatment introduced was probabilistic antibiotherapy followed by a second course of antibiotics after aspiration. The trend confirmed that this was not the correct treatment and that surgery was the only way to achieve a cure.

Trajectories of smokeless tobacco use and of cigarette smoking in a cohort of Swedish adolescents: differences and implications.

Developmental trajectories of cigarette smoking have often been described, but there are no such analyses dealing with smokeless tobacco use. A semi-parametric group-based mixture modeling procedure was used to determine the development of smokeless tobacco (snus) use, as well as of cigarette smoking, over time in a cohort of 2,175 Swedish adolescents who were never-users of tobacco at the time of recruitment. An indicator of snus and of cigarette consumption in the previous year was used to model the development of the behavior between 11 and 18 years of age. For snus use three trajectories best described the cohort's experience, while four trajectories provided the best description of cigarette smoking in the cohort. For both tobacco types there were two escalation patterns and one sustained trial trajectory, while an extinction pattern was apparent for cigarette smoking only. Marked sex differences were found, since rapid escalation for snus use was found only among males while high consumption of cigarettes was observed only among females. Dual users (54.9% of all users) showed a trajectory of steeper and more prolonged increase of tobacco consumption than exclusive users of either snus or cigarettes. Several risk factors for tobacco use measured at baseline influenced individual probabilities of belonging to a particular trajectory. The developmental patterns of snus use and cigarette smoking showed high similarity, but they evolved differently in the two sexes. Dual users emerged as a high-risk group for tobacco dependence and tobacco-related harms.

Testing anonymous link procedures for follow-up of adolescents in a school-based trial: the EU-DAP pilot study.

OBJECTIVE: To study the feasibility of an anonymous coding procedure linking longitudinal information in a multi-center trial of substance abuse prevention among adolescents. METHODS: A school-based survey with re-test procedure was conducted among 485 students (mean age 13.8 years) from three countries at four study centers in order to study accuracy and repeatability of a self-generated anonymous code. RESULTS: Errors affected 18% of codes and 3% of all digits required for the code generation, with highest figures for two of the seven generation items. Sixty-one percent of the codes generated at the test were repeated identically at the re-test. Seventy-six percent of the codes could be linked excluding the 2 digits with the highest error rate in code generation, while 92% were linked using the best combination of the remaining seven or six digits. There was substantial variation between the centers in the results. CONCLUSIONS: Self-generation of anonymous codes is a feasible, but not a very efficient procedure to link longitudinal data among adolescents. Easy derivation and iterative matching procedures are crucial for achieving high efficiency of this type of anonymous linkage.

A cluster randomized controlled trial of school-based prevention of tobacco, alcohol and drug use: the EU-Dap design and study population.

BACKGROUND: The empirical evidence of effectiveness of many school-based programs against substance abuse is rather weak. The EU-Dap study is a multicenter cluster randomized community trial (CRCT) designed to evaluate such a program. This paper presents study design and baseline characteristics of the study population. METHODS: 170 schools from 9 centers from seven countries (Austria, Belgium, Germany, Greece, Italy, Spain, Sweden), stratified according to average social status in the catchment area, were randomized to either three variants of the active intervention (basic curriculum, basic with peer involvement, and basic with parent involvement) or to a control group. The program under evaluation is based on a comprehensive social influence approach, and was delivered during the scholar year 2004-2005 to a population of 12- to 14-year-old students attending junior high school. An anonymous questionnaire administered before and after the intervention was used to track behavioral and attitudinal changes. RESULTS: All in all, we included in the study 143 schools and 7079 students, of which 3547 in the intervention groups and 3532 in the control group. At baseline, 34.9% of students had smoked cigarettes, 24.7% had been drunk, and 8.9% had used cannabis at least once in life. DISCUSSION: EU-Dap is the first European multicenter randomized study to evaluate the effectiveness of a school program targeting tobacco, alcohol and drug use. The baseline assessment showed high prevalence and wide geographical variations of substance use.

Knowledge about tobacco and subsequent use of cigarettes and smokeless tobacco among Swedish adolescents.

PURPOSE: To investigate whether knowledge of the risks and properties of tobacco among adolescents influences their future use of cigarettes and smokeless tobacco in different directions. METHODS: A prospective cohort study of 2581 adolescents whose knowledge of tobacco was assessed in the sixth grade by means of a multi-item scale. Tobacco use was assessed by annual surveys up to the ninth grade. RESULTS: Knowledge level was not associated with future use. Items dealing with addictive properties of nicotine were prospectively associated with smokeless tobacco ("snus") use only. CONCLUSIONS: A high level of knowledge of the risks associated with tobacco is not a predictor of future nonuse or of a shift to smokeless tobacco rather than cigarettes. Attitudes and expectations may determine knowledge rather than vice versa.

Cigarette smoking and the risk of goitre and thyroid nodules amongst parous women.

OBJECTIVES: To clarify the mechanisms by which smoking is associated to toxic and nontoxic goitre and thyroid nodules. DESIGN: Cohort study. SETTING: Sweden. SUBJECTS: A cohort of 874,507 parous women identified through the Medical Birth Registry, with smoking behaviour assessed through self-reported information at the first pre-natal visit, and follow-up between 1983 and 1997. MAIN OUTCOME MEASURES: Hospital diagnoses of toxic and nontoxic goitre and thyroid nodules, identified by record-linkage with the national Inpatient Registry. Cox regression was employed to estimate the hazard ratio (HR) of smokers compared with nonsmokers and the corresponding 95% confidence limits (CL). RESULTS: There was a significantly increased risk of goitre and nodules amongst smokers. The positive association was stronger for toxic (age adjusted HR = 1.94, CL = 1.74-2.16) than for nontoxic goitre and nodules (age-adjusted HR = 1.26; CL = 1.14-1.38). There was generally no clear risk trend with regard to amount smoked (below and above 10 cigarettes per day). Elevated body mass attenuated these associations, whilst being born in Swedish areas of endemic goitre enhanced the association with nontoxic goitre and nodules. CONCLUSIONS: Smoking enhances the risk of thyroid goitre and nodules requiring hospital admission. Iodine deficiency and body weight are likely to be important modifiers of the risk of thyroid hyperplastic diseases amongst smokers.

Validity of self reports in a cohort of Swedish adolescent smokers and smokeless tobacco (snus) users.

OBJECTIVE: To validate self reports of cigarette and smokeless tobacco (snus) use in a prospective cohort of adolescents. DESIGN: A cross sectional analysis of a cohort sub-sample. SETTING: County of Stockholm, Sweden. SUBJECTS: 520 adolescents in the final grade of junior high school (mean age 15.0 years). MAIN OUTCOME MEASURE: Concordance between self reported tobacco use and saliva cotinine concentration. RESULTS: Using a cut point of 5 ng/ml saliva cotinine to discriminate active tobacco use, there was a 98% concordance between self reported non-use in the past month and cotinine concentration. The sensitivity of the questionnaire compared to the saliva cotinine test, used as the gold standard, was 90% and the specificity 93%. One hundred and fifteen out of 520 subjects (22%) reported monthly tobacco use. Among these, 67% (46/69) of the exclusive cigarette smokers, 82% (23/28) of exclusive snus users, and 94% (15/16) of mixed users (cigarettes + snus) had cotinine concentrations above 5 ng/ml. Among subjects reporting daily use 96% (64/67) had saliva cotinine concentrations above the cut point. Exclusive current cigarette users were more likely to be classified discordantly by questionnaire and cotinine test compared to snus users (odds ratio 3.2, 95% confidence interval 1.2 to 8.6). CONCLUSION: This study confirms the reliability of adolescents' self reported tobacco use. In a context of low exposure to environmental tobacco smoke a cut off for saliva cotinine of 5 ng/ml reliably discriminated tobacco users from non-users. Irregular use of tobacco in this age group probably explains the discrepancy between self reported use and cotinine concentrations.

[Epidemiology and antimicrobial resistance of Streptococcus pneumoniae strains isolated in Ile de France area during 2001]. / Epidémiologie et résistance aux antibiotiques de Streptococcus pneumoniae en Ile de France en 2001.

OBJECTIVE: The authors wanted to assess the level of Streptococcus pneumoniae antibiotic resistance in Ile de France. METHOD: In 2001, 637 clinical strains of S. pneumoniae were prospectively collected from 32 microbiology laboratories. RESULTS: Fifty one percent of strains were isolated from children under 15 years of age and 49% from adults. In children, 76% of strains came from otitis media, 20% from blood culture, in adults most strains (92%) came from blood culture. The overall prevalence of non-susceptible penicillin pneumococci was 61% higher in children (73%) than in adults (50%). Among the non-susceptible penicillin pneumococci 21.8% were resistant (CMI > 1 mg/l). Strains with decreased susceptibility to amoxicillin and cefotaxime were 38% and 17% respectively. Resistant strains to these two drugs (CMI > 2 mg/l) were rare 2.6% and 0.4% respectively. Among other antimicrobial agents, rate of resistance was 63% to erythromycin, 47% to cotrimoxazole, 40% to tetracycline, and 23% to chloramphenicol. The most frequent serogroups were serogroups 19 and 14, respectively 23% and 18%. Serotypes included in heptavalent vaccine covered 90% of children strains under 2 years of age. CONCLUSIONS: The prevalence of resistance to penicillin was high in children particularly in otitis media pus (76%).

Role of snus (oral moist snuff ) in smoking cessation and smoking reduction in Sweden.

AIMS: To assess to what extent snus has been used as an aid to stop smoking among Swedish smokers. DESIGN: A random telephone retrospective survey of Swedish smokers and ex-smokers. SETTING: Survey conducted in November-December 2000. PARTICIPANTS: A national sample of 1000 former and 985 current daily smokers aged 25-55 years. MEASUREMENTS: Smoking status, date and method of quitting by self-report. FINDINGS: Thirty-three per cent of former smokers and 27% of current smokers had ever used snus. The difference was larger among men (55% versus 45%, P = 0.003). Current smokers who made use of snus smoked on average fewer cigarettes per day than non-users of snus. The mean duration of abstinence among former smokers was not influenced by snus use. Conditionally on age, education and use of nicotine replacement therapy there was an increased probability of being a former rather than a current smoker with ever use (OR 1.72, 95% CI = 1.30-2.28) or current use (OR 1.81, 95% CI = 1.31-2.53) of snus. Having used snus at the latest quit attempt increased the probability of being abstinent by about 50% (OR 1.54, 95% CI = 1.09-2.20). CONCLUSIONS: Our study suggests that by using snus, Swedish male smokers may increase their overall chances of abstinence. However, 71% of the men in this sample who quit smoking did so without using snus and the duration of abstinence was not affected by snus use. This suggests that snus is not a necessary component of smoking cessation at the population level. Snus use was very rare among women.