Development and validation of open-source deep neural networks for comprehensive chest x-ray reading: a retrospective, multicentre study.

BACKGROUND: Artificial intelligence (AI) systems for automated chest x-ray interpretation hold promise for standardising reporting and reducing delays in health systems with shortages of trained radiologists. Yet, there are few freely accessible AI systems trained on large datasets for practitioners to use with their own data with a view to accelerating clinical deployment of AI systems in radiology. We aimed to contribute an AI system for comprehensive chest x-ray abnormality detection. METHODS: In this retrospective cohort study, we developed open-source neural networks, X-Raydar and X-Raydar-NLP, for classifying common chest x-ray findings from images and their free-text reports. Our networks were developed using data from six UK hospitals from three National Health Service (NHS) Trusts (University Hospitals Coventry and Warwickshire NHS Trust, University Hospitals Birmingham NHS Foundation Trust, and University Hospitals Leicester NHS Trust) collectively contributing 2 513 546 chest x-ray studies taken from a 13-year period (2006-19), which yielded 1 940 508 usable free-text radiological reports written by the contemporary assessing radiologist (collectively referred to as the "historic reporters") and 1 896 034 frontal images. Chest x-rays were labelled using a taxonomy of 37 findings by a custom-trained natural language processing (NLP) algorithm, X-Raydar-NLP, from the original free-text reports. X-Raydar-NLP was trained on 23 230 manually annotated reports and tested on 4551 reports from all hospitals. 1 694 921 labelled images from the training set and 89 238 from the validation set were then used to train a multi-label image classifier. Our algorithms were evaluated on three retrospective datasets: a set of exams sampled randomly from the full NHS dataset reported during clinical practice and annotated using NLP (n=103 328); a consensus set sampled from all six hospitals annotated by three expert radiologists (two independent annotators for each image and a third consultant to facilitate disagreement resolution) under research conditions (n=1427); and an independent dataset, MIMIC-CXR, consisting of NLP-annotated exams (n=252 374). FINDINGS: X-Raydar achieved a mean AUC of 0·919 (SD 0·039) on the auto-labelled set, 0·864 (0·102) on the consensus set, and 0·842 (0·074) on the MIMIC-CXR test, demonstrating similar performance to the historic clinical radiologist reporters, as assessed on the consensus set, for multiple clinically important findings, including pneumothorax, parenchymal opacification, and parenchymal mass or nodules. On the consensus set, X-Raydar outperformed historical reporter balanced accuracy with significance on 27 of 37 findings, was non-inferior on nine, and inferior on one finding, resulting in an average improvement of 13·3% (SD 13·1) to 0·763 (0·110), including a mean 5·6% (13·2) improvement in critical findings to 0·826 (0·119). INTERPRETATION: Our study shows that automated classification of chest x-rays under a comprehensive taxonomy can achieve performance levels similar to those of historical reporters and exhibit robust generalisation to external data. The open-sourced neural networks can serve as foundation models for further research and are freely available to the research community. FUNDING: Wellcome Trust.

Exercise prehabilitation during neoadjuvant chemotherapy may enhance tumour regression in oesophageal cancer: results from a prospective non-randomised trial.

BACKGROUND: There is increasing evidence for the use of exercise in cancer patients and data supporting enhanced tumour volume reduction following chemotherapy in animal models. To date, there is no reported histopathological evidence of a similar oncological benefit in oesophageal cancer. METHODS: A prospective non-randomised trial compared a structured prehabilitation exercise intervention during neoadjuvant chemotherapy and surgery versus conventional best-practice for oesophageal cancer patients. Biochemical and body composition analyses were performed at multiple time points. Outcome measures included radiological and pathological markers of disease regression. Logistic regression calculated ORs with 95% CI for the likelihood of pathological response adjusting for chemotherapy regimen and chemotherapy delivery. RESULTS: Comparison of the Intervention (n=21) and Control (n=19) groups indicated the Intervention group had higher rates of tumour regression (Mandard TRG 1-3 Intervention n=15/20 (75%) vs Control n=7/19 (36.8%) p=0.025) including adjusted analyses (OR 6.57; 95% CI 1.52 to 28.30). Combined tumour and node downstaging (Intervention n=9 (42.9%) vs Control n=3 (15.8%) p=0.089) and Fat Free Mass index were also improved (Intervention 17.8 vs 18.7 kg/m2; Control 16.3 vs 14.7 kg/m2, p=0.026). Differences in markers of immunity (CD-3 and CD-8) and inflammation (IL-6, VEGF, INF-y, TNFa, MCP-1 and EGF) were observed. CONCLUSION: The results suggest improved tumour regression and downstaging in the exercise intervention group and should prompt larger studies on this topic. TRIAL REGISTRATION NUMBER: NCT03626610.

Culprit Vessel Revascularization Prior to Diagnostic Angiography as a Strategy to Reduce Delays in Primary Percutaneous Coronary Intervention: A Propensity-Matched Analysis.

BACKGROUND: Delays are important markers of quality of care in primary percutaneous coronary intervention. There is scarce data on the impact of obtaining a complete diagnostic angiography before primary percutaneous coronary intervention. METHODS AND RESULTS: Consecutive patients treated with primary percutaneous coronary intervention at our institution between January 2012 and December 2014 were studied. After excluding patients with prior coronary artery bypass surgery, 925 patients were included in the analysis. Patients were classified into 3 groups according to the as-treated revascularization strategy: culprit-vessel revascularization first, contralateral angiography first, or complete angiography first. Propensity score matching was used to minimize difference in clinical characteristics between groups. Predictors of culprit-vessel first revascularization were anterior/lateral infarct location and absence of diabetes mellitus. After propensity score matching, the median vascular access-to-balloon time was 4 to 6 minutes shorter with a culprit-vessel revascularization first strategy. This reduction in time to reperfusion increased the proportion of patients treated within recommended delays. However, there was no significant difference in 30-day clinical outcomes associated with these delays reduction. CONCLUSIONS: Performing culprit-vessel primary percutaneous coronary intervention before contralateral or complete diagnostic angiography is associated with a statistically significant reduction in vascular access-to-balloon time, although the 4- to 6-minute difference is unlikely to be clinically relevant. This small but significant reduction could translate in an augmentation in the proportion of patients treated within recommended delays.

Cohort Profile: The Nicotine Dependence in Teens (NDIT) Study.

The Nicotine Dependence in Teens (NDIT) study is a prospective cohort investigation of 1294 students recruited in 1999-2000 from all grade 7 classes in a convenience sample of 10 high schools in Montreal, Canada. Its primary objectives were to study the natural course and determinants of cigarette smoking and nicotine dependence in novice smokers. The main source of data was self-report questionnaires administered in class at school every 3 months from grade 7 to grade 11 (1999-2005), for a total of 20 survey cycles during high school education. Questionnaires were also completed after graduation from high school in 2007-08 and 2011-12 (survey cycles 21 and 22, respectively) when participants were aged 20 and 24 years on average, respectively. In addition to its primary objectives, NDIT has embedded studies on obesity, blood pressure, physical activity, team sports, sedentary behaviour, diet, genetics, alcohol use, use of illicit drugs, second-hand smoke, gambling, sleep and mental health. Results to date are described in 58 publications, 20 manuscripts in preparation, 13 MSc and PhD theses and 111 conference presentations. Access to NDIT data is open to university-appointed or affiliated investigators and to masters, doctoral and postdoctoral students, through their primary supervisor (www.nditstudy.ca).

Weight change in patients attempting to quit smoking post-myocardial infarction.

BACKGROUND: Current guidelines recommend smoking cessation and weight management for secondary prevention in patients post-myocardial infarction. However, little is known about the effects of smoking cessation on weight change post-myocardial infarction. METHODS: We examined patterns of weight change and its effects on blood pressure and glycemic control using data from a randomized trial investigating the effect of bupropion on smoking cessation in patients post-myocardial infarction. Weight change was compared among 3 groups of patients: those who were completely abstinent (n = 92), those who smoked intermittently (n = 49), and those who smoked persistently (n = 38) during the 12-month follow-up. Analyses were restricted to patients who attended all follow-up visits. RESULTS: The median weight at baseline was 77.1 kg (interquartile range [IQR], 66.0, 87.5), and 64.3% of patients were overweight/obese (body mass index ≥25.0 kg/m(2)). The median weight gain at 12 months was 4.0 kg (IQR, 0-7.0), with more than one third gaining >5 kg. The proportion of patients who were overweight/obese increased by approximately 10%, and 23.2% of patients moved up a body mass index category. Abstainers gained a median of 4.8 kg (IQR, 1.0, 8.6), intermittent smokers gained a median of 2.0 kg (IQR, -2.0, 5.0), and persistent smokers gained a median of 3.0 kg (IQR, -0.8, 6.0). Weight gain was associated with an increase in blood pressure and requirements for hypoglycemic medications at 12 months. CONCLUSIONS: The majority of patients attempting to quit smoking gain weight 12 months post-myocardial infarction, with abstainers gaining more weight than those who return to smoking. Weight gain was associated with an increased prevalence of hypertension and diabetes.

Bupropion for smoking cessation in patients hospitalized with acute myocardial infarction: a randomized, placebo-controlled trial.

OBJECTIVES: The purpose of this study was to examine smoking cessation rates among smokers with AMI to determine whether bupropion, started in-hospital, is safe and can improve cessation rates at 1 year. BACKGROUND: Bupropion doubles quit rates in otherwise healthy smokers and patients with stable cardiovascular disease. Although 2 previous trials examined the use of bupropion in patients hospitalized with acute cardiovascular disease, these studies have been inconclusive with respect to its safety and efficacy in patients with acute myocardial infarction (AMI). METHODS: We conducted a multicenter, double-blind, placebo-controlled, randomized trial in smokers hospitalized with AMI. Participants received bupropion or placebo for 9 weeks and were followed for 12 months. Both groups received low-intensity counseling. Point prevalence abstinence was assessed by 7-day recall and biochemical validation of expired carbon monoxide. RESULTS: A total of 392 patients were randomized (mean age 53.9 ± 10.3 years); 83.5% were male; 64.9% had ST-segment elevation myocardial infarction). Patients smoked a mean of 23.2 ± 10.6 cigarettes/day for a mean of 32.9 ± 12.4 years. At 12 months, point prevalence abstinence rates were 37.2% in the bupropion group and 32.0% in the placebo group (p = 0.33; % difference after adjusting for between center differences 3.9%). Continuous abstinence rates were 26.8% and 22.2%, respectively (p = 0.34). Major adverse cardiac event rates were similar (13.0% vs. 11.0%, respectively; p = 0.64). CONCLUSIONS: Two-thirds of patients return to smoking by 12 months after AMI. Bupropion is well tolerated and seems to be safe to use in the immediate post-AMI period. However, bupropion is not effective for smoking cessation in patients post-AMI.

Reduction of delays in primary percutaneous coronary intervention.

BACKGROUND: Acute myocardial infarction is a major health issue. Primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction was proved to be superior to fibrinolytic therapy in many randomized trials when done in a timely manner. However, PPCI is associated with delays. Studies have shown that greater delay is associated with increased mortality rate. We applied simple interventions to reduce door-to-balloon time. Our study goal was to evaluate the reduction of delays after our interventions and to monitor 30-day mortality. METHODS: A prospective registry was created to evaluate delays and mortality associated with PPCI. Measures such as annual feedback with suggestions were taken to minimize the delays. Door-to-balloon delays before and after the interventions were compared. RESULTS: A total of 1361 primary PCIs were performed from 2005 to 2008. Of these cases, 1071 patients were transferred from community hospitals. The median door-to-balloon time for transferred patients was 142 minutes for 2005, 138 minutes for 2006, 125 minutes for 2007, and 121 minutes for 2008 (P < 0.001 for 2005 vs. 2008). Door-to-balloon time for patients admitted directly to our centre was 87 minutes in 2005, 74.5 minutes in 2006, 73.5 minutes in 2007, and 74.0 minutes in 2008 (P < 0.001 for 2005 vs. 2008). Thirty-day mortality of these consecutive patients is low (5.2% for 2005 and 3.8% for 2008; P = not significant). CONCLUSIONS: Inexpensive and simple interventions may significantly reduce primary PCI-related delays for transferred cases and patients admitted directly to a centre with PPCI facilities. We also observed a low mortality rate for those consecutive patients.

Physician smoking status may influence cessation counseling practices.

OBJECTIVE: Smoking cessation counseling practices may differ between physicians who smoke and those who have quit or never smoked. METHOD: Of 917 general practitioners (GP) in Montreal mailed self-report questionnaires in 2000 and 2004, 610 provided data on their smoking status and counseling practices. RESULTS: Seven percent were current smokers, 32% were former smokers, and 61% were never-smokers. Current smokers were more interested than never- or former smokers in learning about counseling methods (64%, 56%, 45%, respectively; p = 0.018). In multivariable analyses, current smokers were less likely than never-smokers to ascertain the smoking status of their patients (OR 0.6, 95% CI 0.2-1.6); to provide advice on how to quit (OR 0.6, 0.3-1.3); and to provide complete cessation counseling coverage (OR 0.5, 0.2-1.1). Former smokers were more likely to provide adjunct support (OR 1.5, 1.0-2.4). CONCLUSION: GP smoking status was associated with the content of their cessation interventions with patients who smoke. Taking physician smoking status into consideration in the design of cessation training programs may improve cessation counseling interventions.

The efficacy of smoking cessation therapies in cardiac patients: a meta-analysis of randomized controlled trials.

INTRODUCTION: Several meta-analyses have examined the efficacy of smoking cessation therapies in the general population. However, little is known about the efficacy of these therapies in cardiac patients. Therefore, a meta-analysis of randomized controlled trials (RCTs) was performed to determine the efficacy of behavioural therapy and pharmacotherapy for smoking cessation in cardiac patients. METHODS: The medical literature was systematically reviewed to identify smoking cessation RCTs in cardiac patients. Only RCTs that reported smoking abstinence at six or 12 months were included. Smoking abstinence was examined based on the 'most rigorous criterion', defined as the most conservative outcome reported in any given RCT. RESULTS: Eleven behavioural therapy RCTs that enrolled 2105 patients and four pharmacotherapy RCTs that enrolled 1542 patients were identified. RCTs differed in the type of behavioural therapy administered as well as the total length and duration of the intervention. RCTs differed in the type of pharmacotherapy administered (one nicotine patch RCT, one nicotine gum RCT and two bupropion RCTs). Behavioural therapy was associated with a significantly higher proportion of smoking abstinence than usual care (OR 1.97 [95% CI 1.37 to 2.85]). Pharmacotherapies were more efficacious than placebo (pooled OR 1.72 [95% CI 1.15 to 2.57]). CONCLUSIONS: Both behavioural therapy and pharmacotherapy are more efficacious than usual care for smoking cessation in cardiac patients. The present meta-analysis highlights the need for head-to-head RCTs to identify which smoking cessation therapy is preferred in cardiac patients as well as RCTs examining the efficacy of combined behavioural and pharmacotherapies.

A systematic review of the Diagnostic and Statistical Manual diagnostic criteria for nicotine dependence.

The Diagnostic and Statistical Manual diagnostic criteria for nicotine dependence (DSM-ND) are based on the proposition that dependence is a syndrome that can be diagnosed only when a minimum of 3 of the 7 proscribed features are present. The DSM-ND criteria are an accepted research measure, but the validity of these criteria has not been subjected to a systematic evaluation. To systematically review evidence of validity and reliability for the DSM-ND criteria, a literature search was conducted of 16 national and international databases. Each article with original data was independently reviewed by two or more reviewers. In total, 380 potentially relevant articles were examined and 169 were reviewed in depth. The DSM-ND criteria have seen wide use in research settings, but sensitivity and specificity are well below the accepted standards for clinical applications. Predictive validity is generally poor. The 7 DSM-ND criteria are regarded as having face validity, but no data support a 3-symptom ND diagnostic threshold, or a 4-symptom withdrawal syndrome threshold. The DSM incorrectly states that daily smoking is a prerequisite for withdrawal symptoms. The DSM shows poor to modest concurrence with all other measures of nicotine dependence, smoking behaviors and biological measures of tobacco use. The data support the DSM-ND criteria as a valid measure of nicotine dependence severity for research applications. However, the data do not support the central premise of a 3-symptom diagnostic threshold, and no data establish that the DSM-ND criteria provide an accurate diagnosis of nicotine dependence.

Familial unruptured sinus of Valsalva aneurysm obstructing the right ventricular outflow tract.

A case demonstrating compression of the right ventricular outflow tract by an unruptured coronary sinus of Valsalva aneurysm in which repair resulted in symptomatic improvement is presented. The pathology report revealed that the patient's younger brother had died from a ruptured aneurysm of the coronary sinus of Valsalva. The present report is the first to describe a familial unruptured coronary sinus of Valsalva aneurysm raising questions regarding the screening of relatives of patients with sinus of Valsalva aneurysms of unknown etiology.

Behavioural interventions for smoking cessation: a meta-analysis of randomized controlled trials.

AIMS: Widely varying estimates of treatment effects have been reported in randomized controlled trials (RCTs) investigating the efficacy of behavioural interventions for smoking cessation. Previous meta-analyses investigating behavioural interventions have important limitations and do not include recently published RCTs. We undertook a meta-analysis of RCTs to synthesize the treatment effects of four behavioural interventions, including minimal clinical intervention (brief advice from a healthcare worker), and intensive interventions, including individual, group, and telephone counselling. METHODS AND RESULTS: We searched the CDC Tobacco Information and Prevention, Cochrane Library, EMBASE, Medline, and PsycINFO databases. We included only RCTs that reported biochemically validated smoking cessation outcomes at 6 and/or 12 months after the target quit date. Outcomes were aggregated using hierarchical Bayesian random-effects models. We identified 50 RCTs, which randomized n = 26 927 patients (minimal clinical intervention: 9 RCTs, n = 6456; individual counselling: 23 RCTs, n = 8646; group counselling: 12 RCTs, n = 3600; telephone counselling: 10 RCTs, n = 8225). The estimated mean treatment effects were minimal clinical intervention [odds ratio (OR) 1.50, 95% credible interval (CrI) 0.84-2.78], individual counselling (OR 1.49, 95% CrI 1.08-2.07), group counselling (OR 1.76, 95% CrI 1.11-2.93), and telephone counselling (OR 1.58, 95% CrI 1.15-2.29). CONCLUSION: Intensive behavioural interventions result in substantial increases in smoking abstinence compared with control. Although minimal clinical intervention may increase smoking abstinence, there is insufficient evidence to draw strong conclusions regarding its efficacy.

Milestones in the process of cessation among novice adolescent smokers.

OBJECTIVES: We sought to document the sequence and timing of milestones in the process of smoking cessation by prospectively studied cessation milestones among novice adolescent smokers. METHODS: Participants, aged 12 to 13 years in 1999 (n = 1293), completed self-report questionnaires every 3 months during the school year over 5 years. We ascertained time after first puff to attain 5 cessation milestones among 319 participants who initiated cigarette smoking during follow-up. RESULTS: The cumulative probability of first reports of a serious desire to quit and perceived permanent cessation was 25% at 1.5 months (95% confidence interval [CI] = 1.5, 2.5) after the first puff. The first serious quit attempt occurred at 2.5 months (95% CI = 2.5, 5.4), lack of confidence about quitting followed at 18.4 months (95% CI = 18.4, 26.8), and awareness of the difficulty of quitting occurred at 32.2 months (95% CI = 19.2, 38.4). CONCLUSIONS: Desire and attempts to quit began soon after smoking onset. Novice smokers progressed through several stages in their perception of the difficulty of quitting. Increased understanding of the cessation process may help in developing effective tobacco control interventions for novice smokers.

Nicotine dependence symptoms among young never-smokers exposed to secondhand tobacco smoke.

BACKGROUND: To extend previous observations that secondhand tobacco smoke (SHS) is associated with nicotine markers in children, we investigated if SHS exposure is associated with self-reports of nicotine dependence (ND) symptoms among young never-smokers. METHOD: Data on number of persons who smoke inside the home, number of days exposed to SHS in a motor vehicle in the past week, number of parents, siblings, and friends who smoke, and ND symptoms, were collected from 10-12 year-old students in self-report questionnaires. The association between SHS and ND symptoms among young never-smokers was assessed in logistic regression models. RESULTS: Sixty-nine of 1488 never-smokers (5%) reported one or more ND symptom. After controlling for sibling and peer smoking, and susceptibility to initiating smoking, exposure to SHS in a motor vehicle was independently associated with ND symptoms (OR, 95% CI=1.2, 1.0-1.4). The OR for number of persons who smoke inside the home was 1.1 (0.9-1.4). CONCLUSION: SHS exposure in motor vehicles may be associated with ND symptoms among young never-smokers. If replicated, this finding provides support for interventions that promote non-smoking in motor vehicles.

Pharmacotherapies for smoking cessation: a meta-analysis of randomized controlled trials.

BACKGROUND: Many placebo-controlled trials have demonstrated the efficacy of individual pharmacotherapies approved for smoking cessation. However, few direct or indirect comparisons of such interventions have been conducted. We performed a meta-analysis to compare the treatment effects of 7 approved pharmacologic interventions for smoking cessation. METHODS: We searched the US Centers for Disease Control and Prevention's Tobacco Information and Prevention database as well as MEDLINE, EMBASE and the Cochrane Library for published reports of placebo-controlled, double-blind randomized controlled trials of pharmacotherapies for smoking cessation. We included studies that reported biochemically validated measures of abstinence at 6 and 12 months. We used a hierarchical Bayesian random-effects model to summarize the results for each intervention. RESULTS: We identified 70 published reports of 69 trials involving a total of 32 908 patients. Six of the 7 pharmacotherapies studied were found to be more efficacious than placebo: varenicline (odds ratio [OR] 2.41, 95% credible interval [CrI] 1.91-3.12), nicotine nasal spray (OR 2.37, 95% CrI 1.12-5.13), bupropion (OR 2.07, 95% CrI 1.73-2.55), transdermal nicotine (OR 2.07, 95% CrI 1.69-2.62), nicotine tablet (OR 2.06, 95% CrI 1.12-5.13) and nicotine gum (OR 1.71, 95% CrI 1.35-2.21). Similar results were obtained regardless of which measure of abstinence was used. Although the point estimate favoured nicotine inhaler over placebo (OR 2.17), these results were not conclusive because the credible interval included unity (95% CrI 0.95-5.43). When all 7 interventions were included in the same model, all were more efficacious than placebo. In our analysis of data from the varenicline trials that included bupropion control arms, we found that varenicline was superior to bupropion (OR 2.18, 95% CrI 1.09-4.08). INTERPRETATION: Varenicline, bupropion and the 5 nicotine replacement therapies were all more efficacious than placebo at promoting smoking abstinence at 6 and 12 months.

Canadian Thoracic Society recommendations for management of chronic obstructive pulmonary disease - 2008 update - highlights for primary care.

Chronic obstructive pulmonary disease (COPD) is a major respiratory illness in Canada that is preventable and treatable but unfortunately remains underdiagnosed. The purpose of the present article from the Canadian Thoracic Society is to provide up-to-date information so that patients with this condition receive optimal care that is firmly based on scientific evidence. Important summary messages for clinicians are derived from the more detailed Update publication and are highlighted throughout the document. Three key messages contained in the update are: use targeted screening spirometry to establish a diagnosis and initiate prompt management (including smoking cessation) of mild COPD; improve dyspnea and activity limitation in stable COPD using new evidence-based treatment algorithms; and understand the importance of preventing and managing acute exacerbations, particularly in moderate to severe disease.

Smoking cessation attempts among adolescent smokers: a systematic review of prevalence studies.

OBJECTIVE: To synthesise estimates of the prevalence of cessation attempts among adolescent smokers generally, and according to age and level of cigarette consumption. DATA SOURCES: PubMed, ERIC, and PsychInfo databases and Internet searches of central data collection agencies. STUDY SELECTION: National population-based studies published in English between 1990 and 2005 reporting the prevalence, frequency and/or duration of cessation attempts among smokers aged >or=10 to <20 years. DATA EXTRACTION: Five reviewers determined inclusion criteria for full-text reports. One reviewer extracted data on the design, population characteristics and results from the reports. DATA SYNTHESIS: In total, 52 studies conformed to the inclusion criteria. The marked heterogeneity that characterised the study populations and survey questions precluded a meta-analysis. Among adolescent current smokers, the median 6-month, 12-month and lifetime cessation attempt prevalence was 58% (range: 22-73%), 68% (range 43-92%) and 71% (range 28-84%), respectively. More than half had made multiple attempts. Among smokers who had attempted cessation, the median prevalence of relapse was 34, 56, 89 and 92% within 1 week, 1 month, 6 months, and 1 year, respectively, following the longest attempt. Younger (age<16 years) and non-daily smokers experienced a similar or higher prevalence of cessation attempts compared with older (age >or=16 years) or daily smokers. Moreover, the prevalence of relapse by 6 months following the longest cessation attempt was similar across age and smoking frequency. CONCLUSIONS: The high prevalence of cessation attempts and relapse among adolescent smokers extends to young adolescents and non-daily smokers. Cessation surveillance, research and program development should be more inclusive of these subgroups.

Canadian Thoracic Society recommendations for management of chronic obstructive pulmonary disease - 2007 update.

Chronic obstructive pulmonary disease (COPD) is a major respiratory illness in Canada that is both preventable and treatable. Our understanding of the pathophysiology of this complex condition continues to grow and our ability to offer effective treatment to those who suffer from it has improved considerably. The purpose of the present educational initiative of the Canadian Thoracic Society (CTS) is to provide up to date information on new developments in the field so that patients with this condition will receive optimal care that is firmly based on scientific evidence. Since the previous CTS management recommendations were published in 2003, a wealth of new scientific information has become available. The implications of this new knowledge with respect to optimal clinical care have been carefully considered by the CTS Panel and the conclusions are presented in the current document. Highlights of this update include new epidemiological information on mortality and prevalence of COPD, which charts its emergence as a major health problem for women; a new section on common comorbidities in COPD; an increased emphasis on the meaningful benefits of combined pharmacological and nonpharmacological therapies; and a new discussion on the prevention of acute exacerbations. A revised stratification system for severity of airway obstruction is proposed, together with other suggestions on how best to clinically evaluate individual patients with this complex disease. The results of the largest randomized clinical trial ever undertaken in COPD have recently been published, enabling the Panel to make evidence-based recommendations on the role of modern pharmacotherapy. The Panel hopes that these new practice guidelines, which reflect a rigorous analysis of the recent literature, will assist caregivers in the diagnosis and management of this common condition.