MORTALITY IN RELATION TO SMOKING: TEN YEARS' OBSERVATIONS OF BRITISH DOCTORS

Sobre o conceito de risco em Epidemiologia

Resumo Este ensaio teórico analisa a centralidade do conceito de risco para a ciência epidemiológica, descrevendo os tipos de medidas de risco e suas definições, a origem e o desenvolvimento histórico dessas medidas desde o século XVII até o momento atual. Em seguida, são analisadas as fases do desenvolvimento histórico do conceito de risco desde a constituição da disciplina no século XIX, passando pela transposição do limiar de cientificidade, até a atualidade. Após esse recorrido histórico, são apontados os pressupostos epistemológicos do conceito de risco tal qual ele se apresenta na epidemiologia. A polissemia do conceito nos saberes do senso comum e sua formulação em diferentes disciplinas científicas assim como suas diferentes conotações no âmbito da epidemiologia são brevemente comentadas. Finalizamos com a discussão do conceito na chamada sociedade de riscos da modernidade tardia. Consideramos que o ensaio possa ser de utilidade na formação dos profissionais de saúde, tendo em vista seu papel nuclear na epidemiologia e na Saúde Coletiva, não apenas como articulador das proposições teóricas, mas também na orientação das práticas.

Smoking Prevalence among Physicians: A Systematic Review and Meta-Analysis

BACKGROUND

Smoking is a major public health problem. Although physicians have a key role in the fight against smoking, some of them are still smoking. Thus, we aimed to conduct a systematic review and meta-analysis on the prevalence of smoking among physicians.

METHODS

PubMed, Cochrane, and Embase databases were searched. The prevalence of smoking among physicians was estimated and stratified, where possible, by specialties, continents, and periods of time. Then, meta-regressions were performed regarding putative influencing factors such as age and sex.

RESULTS

Among 246 studies and 497,081 physicians, the smoking prevalence among physicians was 21% (95CI 20 to 23%). Prevalence of smoking was 25% in medical students, 24% in family practitioners, 18% in surgical specialties, 17% in psychiatrists, 16% in medical specialties, 11% in anesthesiologists, 9% in radiologists, and 8% in pediatricians. Physicians in Europe and Asia had a higher smoking prevalence than in Oceania. The smoking prevalence among physicians has decreased over time. Male physicians had a higher smoking prevalence. Age did not influence smoking prevalence.

CONCLUSION

Prevalence of smoking among physicians is high, around 21%. Family practitioners and medical students have the highest percentage of smokers. All physicians should benefit from targeted preventive strategies.

Sustainable healthcare - Time for 'Green Podiatry'

Background

Healthcare aims to promote good health and yet demonstrably contributes to climate change, which is purported to be ‘the biggest global health threat of the 21st century’. This is happening now, with healthcare as an industry representing 4.4% of global carbon dioxide emissions.

Main body

Climate change promotes health deficits from many angles; however, primarily it is the use of fossil fuels which increases atmospheric carbon dioxide (also nitrous oxide, and methane). These greenhouse gases prevent the earth from cooling, resulting in the higher temperatures and rising sea levels, which then cause ‘wild weather’ patterns, including floods, storms, and droughts.

Particular vulnerability is afforded to those already health compromised (older people, pregnant women, children, wider health co-morbidities) as well as populations closer to equatorial zones, which encompasses many low-and-middle-income-countries. The paradox here, is that poorer nations by spending less on healthcare, have lower carbon emissions from health-related activity, and yet will suffer most from global warming effects, with scant resources to off-set the increasing health care needs.

Global recognition has forged the Paris agreement, the United Nations sustainable developments goals, and the World Health Organisation climate change action plan. It is agreed that most healthcare impact comes from consumption of energy and resources, and the production of greenhouse gases into the environment.

Many professional associations of medicine and allied health professionals are advocating for their members to lead on environmental sustainability; the Australian Podiatry Association is incorporating climate change into its strategic direction.

Conclusion

Podiatrists, as allied health professionals, have wide community engagement, and hence, can model positive environmental practices, which may be effective in changing wider community behaviours, as occurred last century when doctors stopped smoking.

As foot health consumers, our patients are increasingly likely to expect more sustainable practices and products, including ‘green footwear’ options. Green Podiatry, as a part of sustainable healthcare, directs us to be responsible energy and product consumers, and reduce our workplace emissions.

A Narrative Review of Methods for Causal Inference and Associated Educational Resources

BACKGROUND AND OBJECTIVES

Root cause analysis involves evaluation of causal relationships between exposures (or interventions) and adverse outcomes, such as identification of direct (eg, medication orders missed) and root causes (eg, clinician's fatigue and workload) of adverse rare events. To assess causality requires either randomization or sophisticated methods applied to carefully designed observational studies. In most cases, randomized trials are not feasible in the context of root cause analysis. Using observational data for causal inference, however, presents many challenges in both the design and analysis stages. Methods for observational causal inference often fall outside the toolbox of even well-trained statisticians, thus necessitating workforce training.

METHODS

This article synthesizes the key concepts and statistical perspectives for causal inference, and describes available educational resources, with a focus on observational clinical data. The target audience for this review is clinical researchers with training in fundamental statistics or epidemiology, and statisticians collaborating with those researchers.

RESULTS

The available literature includes a number of textbooks and thousands of review articles. However, using this literature for independent study or clinical training programs is extremely challenging for numerous reasons. First, the published articles often assume an advanced technical background with different notations and terminology. Second, they may be written from any number of perspectives across statistics, epidemiology, computer science, or philosophy. Third, the methods are rapidly expanding and thus difficult to capture within traditional publications. Fourth, even the most fundamental aspects of causal inference (eg, framing the causal question as a target trial) often receive little or no coverage. This review presents an overview of (1) key concepts and frameworks for causal inference and (2) online documents that are publicly available for better assisting researchers to gain the necessary perspectives for functioning effectively within a multidisciplinary team.

CONCLUSION

A familiarity with causal inference methods can help risk managers empirically verify, from observed events, the true causes of adverse sentinel events.

Causal assessment in demographic research

Causation underlies both research and policy interventions. Causal inference in demography is however far from easy, and few causal claims are probably sustainable in this field. This paper targets the assessment of causality in demographic research. It aims to give an overview of the methodology of causal research, pointing out various problems that can occur in practice. The “Intervention studies” section critically examines the so-called gold standard in causality assessment in experimental studies, randomized controlled trials, and the use of quasi-experiments and interventions in observational studies. The “Multivariate statistical models” section deals with multivariate statistical models linking a mortality or fertility indicator to a series of possible causes and controls. Single and multiple equation models are considered. The “Mechanisms and structural causal modelling” section takes into account a more recent trend, i.e., mechanistic explanations in causal research, and develops a structural causal modelling framework stemming from the pioneering work of the Cowles Commission in econometrics and of Sewall Wright in population genetics. The “Assessing causality in demographic research” section examines how causal analysis could be further applied in demographic studies, and a series of proposals are discussed for this purpose. The paper ends with a conclusion pointing out, in particular, the relevance of structural equation models, of triangulation, and of systematic reviews for causal assessment.

Tobacco smoking and the risk of Parkinson disease: A 65-year follow-up of 30,000 male British doctors

OBJECTIVE

To investigate the causal relevance of current tobacco smoking for the risk of Parkinson disease (PD).

METHODS

We compared the risks of death from PD with smoking habits in 30,000 male doctors in the British Doctors cohort study in 1951 and in survivors who had been resurveyed periodically for 5 decades. Cause-specific mortality was monitored for 65 years and included 283 deaths from PD. The relative risks (RRs) of PD (and 95% confidence intervals [CIs]) were estimated using Cox models for smoking habits (smoking status, amount smoked, and years since quitting) at baseline or updated habits at resurvey.

RESULTS

The prevalence of current smoking declined progressively during follow-up from 67% to 8% between 1951 and 1998. The crude rates of PD death were lower in current smokers than in never smokers at baseline (30 vs 46/100,000 persons-years). After adjustment for age at risk, current smokers at baseline had a 30% lower risk of PD (RR 0.71; 95% CI 0.60-0.84), and continuing smokers classified using updated smoking habits at resurvey had a 40% lower risk (RR 0.60; 95% CI 0.46-0.77) of PD compared with never smokers. The risks of PD were inversely associated with the amount of tobacco smoked. The protective effect of current smoking vs never smoking for PD was attenuated by increasing duration since quitting smoking.

CONCLUSIONS

In contrast to previous suggestions, the present report demonstrates a causally protective effect of current smoking on the risk of PD, which may provide insights into the etiology of PD.

Community intervention for cardiovascular disease risk factors in Kalutara, Sri Lanka

BACKGROUND

The effectiveness of a 2015-17 community intervention to reduce cardiovascular disease (CVD) and type 2 diabetes (T2DM) risk factors is assessed in a Sri Lanka adult population, using a before-and-after study design.

METHODS

Four contiguous Public Health Midwife (PHM) areas in Kalutara district (Western Province) were exposed to a Sri Lankan designed community health promotion initiatives (without screening) to lower CVD and T2DM risk factors. Pre- and post-intervention surveys (2014, n=1,019; 2017, n=908) were of 25-64 year males (M) and females (F) from dissimilar randomly selected clusters (villages or settlements) from PHMs, with probability of selection proportional to population size, followed by household sampling, then individual selection to yield equal-probability samples. Differences in resting blood pressure (BP), fasting plasma glucose (FPG), total cholesterol, body mass index and tobacco smoking, adjusting for cluster sampling, age and socio-economic differences, were examined.

RESULTS

Hypertension prevalence declined from 25% to 16% (F) (p<.0001), and 21% to 17% (M). Both mean systolic and diastolic BP declined. T2DM declined from 18% to 13% (F), and 18% to 15% (M), as did mean fasting plasma glucose. Elevated total cholesterol declined from 21% to 15% in women (p=0.003) and mean cholesterol declined. Frequency distributions, medians and means of these continuous CVD risk factors shifted to lower levels, and were mostly statistically significant (p< 0.05).

CONCLUSIONS

Community health promotion can lower key CVD and T2DM risk factors. Lowering tobacco consumption in males and obesity remain challenges in Sri Lanka.

Epidemiology of lung cancer in Northern Greece: An 18-year hospital-based cohort study focused on the differences between smokers and non-smokers

INTRODUCTION

Lung cancer remains a leading cause of cancer incidence, yet, in Greece, country-level registry-based data are limited. We have thus investigated the epidemiology of lung cancer and its trends in the George Papanikolaou Hospital, Northern Greece over 18 years (2000–2018).

METHODS

We analyzed all the cases reported in the Bronchoscopy Unit of the Hospital for the period 2000–2018. In total, 15131 subjects (12300 males and 2831 females) that presented with a mass in the imaging, were submitted to bronchoscopy. Characteristics of patients such as age, sex, smoking history and occupation were collected. Statistical analysis was performed with SPSS 21.0 software package.

RESULTS

Among all subjects, a total of 5628 (37.2%; mean age: 65.85 ± 9.6 years) cases of primary lung cancer were identified with a male to female ratio of 2:1 (41.1% to 20.4%) (p<0.001). Squamous cell lung cancer was the most common type of lung cancer identified in this population (44%) with a higher proportion in males compared to females (p<0.001). Furthermore, adenocarcinoma was mostly observed in female non-smokers compared to males (p<0.001). The majority of lung cancer cases were identified in patients occupied with agriculture and livestock breeding (41.1%). The mean age at lung cancer diagnosis was 66.13 ± 9.19 years for the whole study population. Lung cancer cases observed with a higher mean of 43.93 ± 10.84 years of smoking compared to cancer-free patients with 39.64 ± 13.23 years of smoking (p<0.001).

CONCLUSIONS

Apart from smoking, demographic characteristics including age, sex and occupation appear to have an impact on lung cancer development in this population. Smoking history alone could not predict the development of lung cancer in the studied northern Greek population.

The hazards of smoking and the benefits of cessation: a critical summation of the epidemiological evidence in high-income countries

In high-income countries, the biggest cause of premature death, defined as death before 70 years, is smoking of manufactured cigarettes. Smoking-related disease was responsible for about 41 million deaths in the United States, United Kingdom and Canada, cumulatively, from 1960 to 2020. Every million cigarettes smoked leads to one death in the US and Canada, but slightly more than one death in the UK. The 21^st century hazards reveal that smokers who start smoking early in adult life and do not quit lose a decade of life expectancy versus non-smokers. Cessation, particularly before age 40 years, yields large reductions in mortality risk. Up to two-thirds of deaths among smokers are avoidable at non-smoking death rates, and former smokers have about only a quarter of the excess risk of death compared to current smokers. The gap between scientific and popular understanding of smoking hazards is surprisingly large.

Using the Risk Factors of Pancreatic Cancer and Their Interactions in Cancer Screening: A Case-Control Study in Shanghai, China

Background:

The incidence of pancreatic cancer has increased annually, but the risk factors and their interactions are still unknown.

Objective:

The aim of this study was to identify risk factors and the effects of their interactions on pancreatic cancer occurrence among patients in Shanghai, China.

Methods:

We conducted a hospital-based case-control study. The case group consisted of pathologically diagnosed pancreatic cancer patients, and the control group consisted of a healthy population. The Pearson Chi-square test was used to compare the distribution frequencies of data between groups. Multivariate analysis and interaction analysis were conducted to explore possible risk factors and interactions between various variables.

Findings:

Among the 4,821 recruited participants, 1,392 were pancreatic cancer patients and 3,429 were controls. Multivariate logistic analysis suggested that age (>50 years old) (AOR: 16.20 [95% CI 6.78; 38.69]), diabetes (AOR: 5.40 [95% CI 2.70; 10.80]), chronic pancreatitis (AOR: 27.43 [95% CI 2.14; 351.77]), smoking (AOR: 8.86 [95% CI 3.07; 25.58]), and family cancer history (AOR: 2.10 [95% CI 1.09; 8.56]) were the primary risk factors for pancreatic cancer. Interestingly, synergistic interactions between risk factors were found, especially between age and chronic pancreatitis (RERI = 447.93, API = 96.74%, SI = 32.78), age and smoking (RERI = 187.42, API = 94.97%, SI = 21.99), and diabetes and smoking (RERI = 14.39, API = 48.06%, SI = 1.99).

Conclusions:

Age, diabetes, chronic pancreatitis, smoking, and family cancer history have been verified as the primary risk factors for pancreatic cancer in this study. Moreover, the interaction effects between old age, diabetes, chronic pancreatitis, and smoking substantially increase the probability of the development of pancreatic cancer. Cancer screening should be conducted extensively among people with these multiple factors to improve the efficiency.

A risk of bias instrument for non-randomized studies of exposures: A users' guide to its application in the context of GRADE

The objective of this paper is to explain how to apply, interpret, and present the results of a new instrument to assess the risk of bias (RoB) in non-randomized studies (NRS) dealing with effects of environmental exposures on health outcomes. This instrument is modeled on the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) instrument. The RoB instrument for NRS of exposures assesses RoB along a standardized comparison to a randomized target experiment, instead of the study-design directed RoB approach. We provide specific guidance for the integral steps of developing a research question and target experiment, distinguishing issues of indirectness from RoB, making individual-study judgments, and performing and interpreting sensitivity analyses for RoB judgments across a body of evidence. Also, we present an approach for integrating the RoB assessments within the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework to assess the certainty of the evidence in the systematic review. Finally, we guide the reader through an overall assessment to support the rating of all domains that determine the certainty of a body of evidence using the GRADE approach.

Transitions From Heart Disease to Cancer as the Leading Cause of Death in US States, 1999-2016

Introduction

Heart disease has been the leading cause of death in the United States since 1910 and cancer the second leading cause of death since 1933. However, cancer emerged recently as the leading cause of death in many US states. The objective of this study was to provide an in-depth analysis of age-standardized annual state-specific mortality rates for heart disease and cancer.

Methods

We used population-based mortality data from 1999 through 2016 to compare 2 underlying cause-of-death categories: diseases of heart (International Classification of Diseases, 10th Revision [ICD-10] codes I00–I09, I11, I13, and I20–I51) and malignant neoplasms (ICD-10 codes C00–C97). We calculated age-standardized annual state-specific mortality rate ratios (MRRs) as heart disease mortality rate divided by cancer mortality rate.

Results

In 1999, age-standardized heart disease mortality exceeded that for cancer in all 50 states. Median state-specific MRR in 1999 was 1.26 (interquartile range [IQR], 1.17–1.34; range, 1.03–1.56), indicating predominance of heart disease mortality nationwide. Median state-specific MRR decreased annually through 2010, reaching a low of 1.00 (IQR, 0.95–1.07; range, 0.71–1.25), indicating that predominance of heart disease mortality prevailed in approximately half of states. Median state-specific MRR increased to 1.03 (IQR, 0.97–1.12; range, 0.77–1.31) in 2016. In 2016, age-standardized cancer mortality exceeded that for heart disease in 19 states. State-level transitions were most apparent for people aged 65 to 84 and affected men, women, and all racial/ethnic groups.

Conclusion

State-level data indicated heterogeneity across US states in the predominance of heart disease mortality relative to cancer mortality. Timing and magnitude of transitions toward cancer mortality predominance varied by state.

The importance of cohort research starting early in life to understanding child health

PURPOSE OF REVIEW

The current review addresses the importance of the prospective cohort design in large, unselected populations starting early in life for understanding the origins of childhood health disorders.

RECENT FINDINGS

Cohort studies originating in healthy populations have contributed to great advances in health, especially in cardiovascular diseases, but have only recently been applied systematically to study the origins of childhood disorders. Several large population-based pregnancy and/or birth cohorts have been developed in different parts of the world, and these are beginning to contribute to better understanding of the underlying causes of rare but important childhood disorders, such as autism. The environmental influences on child health outcomes (ECHO) Program is distinct in leveraging and building upon 84 existing cohorts to prospectively investigate the role of early-life exposures and underlying biological mechanisms in childhood health and disease, specifically perinatal conditions, obesity, neurodevelopmental disorders, asthma and related pulmonary disorders as well as optimum child health. ECHO is expected to comprise approximately 50 000 children. It is the first US study of this size and scope since the US Collaborative Perinatal Project of 1959-1966.

SUMMARY

The ECHO project represents a new approach to cohort studies in childhood, efficiently making use of extant cohorts while adding new data collection elements that should permit novel insights into the underlying causes of several important pediatric conditions.

Perforated Duodenal Ulcer and Cigarette Smoking

Whilst the association between smoking and peptic ulceration has been reported previously, the relationship between smoking and the complications of ulcers, such as perforation, bleeding or acute painful exacerbation, has not been examined. In a retrospective study comparing 275 emergency admissions for peptic ulcer with 275 controls, cigarette smoking was significantly more common only in those with a perforated duodenal ulcer. Of 128 patients with perforated duodenal ulcers, 110 (86%) were cigarette smokers compared with 65 (51%) of the 128 matched controls (χ2, P<0.01). Cigarette smoking in patients with bleeding or acutely exacerbated ulcers was not significantly more common than in controls. These findings strongly suggest a particular association between smoking and perforated duodenal ulcer.

Evaluation of a volunteer sample in nasopharyngeal colonization surveys for Streptococcus pneumoniae in rural Alaska

OBJECTIVE

To compare characteristics of persons in rural northern communities who participated in a study on antimicrobial use and drug-resistant Streptococcus pneumoniae (SP) to those who did not participate.

STUDY DESIGN

The original study (1998--2000) was a community-based, controlled intervention trial designed to determine the penicillin susceptibility of nasopharyngeal SP isolates in relation to community-wide use of antibiotics. The study continued after 2000, in a subset of the original communities, to prospectively evaluate the impact of the heptavalent pneumococcal conjugate vaccine on the carriage of SP. The results presented here are an analysis of the first five years of data.

METHODS

We conducted annual surveys (1998--2002) for nasopharyngeal colonization of SP using a volunteer sample of residents in rural communities. Medical chart reviews for health clinic visitation and antibiotic use were completed for all village residents.

RESULTS

Participants were younger (22.8 vs. 28.4 years), had more health clinic utilization (3.3 vs. 2.4 visits) and received more antibiotics (1.0 vs. 0.6 courses) than non-participants. Differences between participants and non-participants were similar across all years of the study.

CONCLUSIONS

Our study provides further empirical evidence that selection bias should be considered when designing studies. However, a volunteer sample provided internal consistency for comparison of our main study outcomes across time.

Psychological distress, neuroticism, and cause-specific mortality: early prospective evidence from UK Biobank

Background

It is well established that psychological distress (depression and anxiety) is related to an increased risk of mortality. The personality trait of neuroticism, reflecting a relatively stable tendency towards negative emotions, has also been associated with elevated rates of death in some studies. Accordingly, we tested the possibility that it is the neuroticism trait itself, rather than the distress state, that is generating an increased risk of mortality.

Methods

We used data from the UK Biobank study, a UK-wide prospective cohort study (2006–2010) in which distress was ascertained using the Patient Health Questionnaire and neuroticism using the Eysenck Personality Questionnaire-Revised Short Form.

Results

A mean of 6.2 years of follow-up of 308 721 study members gave rise to 4334 deaths. Higher neuroticism was weakly associated with total mortality (age-adjusted and sex-adjusted HR per SD increase; 95% CI 1.05; 1.02 to 1.09), and moderately strongly correlated with distress symptoms (r=0.55, p<0.0001). Distress symptoms were positively related to risk of total mortality (age-adjusted and sex-adjusted HR per SD increase in distress; 95% CI 1.23; 1.20 to 1.26). This gradient was, in fact, slightly strengthened after adding neuroticism to the multivariable model (1.30; 1.26 to 1.34) but markedly attenuated after taking into account other covariates which included health behaviours and somatic disease (1.16; 1.12 to 1.20). Similar results were apparent when cardiovascular disease, cancer and external cause of death were the end points of interest.

Conclusions

While there was good a priori reasons to anticipate the neuroticism would at least partially explain the relation between distress symptoms and cause-specific mortality, we found no such evidence in the present study.

Surviving “Risk Factor Frenzy”: The Perils of Incorrectly Applying Epidemiological Research in Health Education and Promotion

In health education and promotion, “risk factors” for disease gathered from epidemiological research form the basis from which the majority of recommendations to individuals for lifestyle change are made. Unfortunately, many health practitioners are unaware that this type of research was never intended to be applied to individuals. The result is ongoing public confusion and anxiety concerning health recommendations and a loss of credibility for health professionals. This article: 1) briefly reviews the most commonly encountered limitations inherent in epidemiological research; 2) explores the problems and potential negative consequences of incorrectly applying epidemiological research in health education and promotion; and 3) makes recommendations to help health practitioners more skillfully interpret and incorporate into their work findings from epidemiological research.

Teratogenic, bioenergetic, and behavioral effects of exposure to total particulate matter on early development of zebrafish (Danio rerio) are not mimicked by nicotine

Cigarette smoke has been associated with a number of pathologies; however, the mechanisms leading to developmental effects are yet to be fully understood. The zebrafish embryo is regarded as a 'bridge model'; however, not many studies examined its applicability to cigarette smoke toxicity. This study examined the effects of total particulate matter (TPM) from 3R4F reference cigarettes on the early development of zebrafish (Danio rerio). Zebrafish embryos were exposed to two concentrations of TPM (0.4 and 1.4 μg/mL equi-nicotine units) or nicotine at equivalent doses. The exposures began at 2h post-fertilization (hpf) and lasted until 96 hpf. Several physiological parameters were assessed during or after the exposure. We show that TPM increased mortality, delayed hatching, and increased the incidence of deformities in zebrafish. TPM exposure also increased the incidence of hemorrhage and disrupted the angiogenesis of the major vessels in the brain. Moreover, TPM exposure reduced the larval body length, decreased the heart rate, and reduced the metabolic rate. Biomarkers of xenobiotic metabolism and oxidative stress were also affected. TPM-exposed zebrafish also differed behaviorally: at 24 hpf the embryos had a higher frequency of spontaneous contractions and at 144 hpf the larvae displayed swimming hyperactivity. This study demonstrates that TPM disrupts several aspects of early development in zebrafish. The effects reported for TPM were not attributable to nicotine, since embryos treated with nicotine alone did not differ significantly from the control group. Collectively, our work illustrates the utility of zebrafish as an alternative model to evaluate the toxic effects of cigarette smoke constituents.

Can intermittent theta burst stimulation as add-on to psychotherapy improve nicotine abstinence? Results from a pilot study

Smoking is among the leading causes of mortality worldwide. Discontinuing smoking can increase life expectancy to the presmoking level. Unaided attempts are often ineffective, strengthening the necessity of cognitive-behavioral therapy (CBT), nicotine replacement or pharmacotherapy. Still, relapse rates are high. Recently, a modulation of nicotine craving, which predicts relapse, through transcranial magnetic stimulation to the prefrontal cortex was shown. In a pilot study, we investigated whether 4 sessions of intermittent theta burst stimulation (iTBS) as add-on treatment to CBT reduces nicotine craving and improves long-term abstinence (at 3, 6 and 12 months). Smokers were randomly assigned to a treatment (n = 38) or a sham group (n = 36). Although we did not find reduced craving, we could show higher abstinence rates in the treatment group at 3 months. At 6 and 12 months abstinence rates did not differ significantly. Results at 12 months, however, have to be interpreted cautiously due to significant differences in the dropout rates between the two groups at this time point. We provide first evidence for a beneficial effect of additional iTBS on intermediate nicotine abstinence; however, the low number of iTBS sessions might have prevented longer effects. More lasting effects might be achieved by iTBS maintenance sessions in analogy to the treatment of depression.

Vasomotor activity of the aorta during chronic smoking modeling

We studied vasomotor responses of aortic endothelium in a rat model of chronic smoking. It was found that long-term exposure to tobacco smoke (inhalation) impaired vasomotor function of the aortic endothelium leading to insufficient vasodilator activity and enhanced vasoconstriction. After the cessation of inhalations, vasomotor disturbances were not only preserved, but also exacerbated because of increased pathological endothelium-independent vasoconstriction.

Lifestyle factors, autoimmune disease and family history in prognosis of non-hodgkin lymphoma overall and subtypes

Lifestyle factors and medical history are known to influence risk of non-Hodgkin lymphoma (NHL). Whether these factors affect the prognosis of NHL, especially its subtypes, is unclear. To investigate this, the association between these factors and all-cause and lymphoma-related mortality was assessed in a population-based cohort of 1,523 Swedish NHL patients included in the Scandinavian Lymphoma Etiology study in 1999-2002. Participants contributed time from NHL diagnosis until death or October 1, 2010, with virtually complete follow-up through linkage to the Swedish Cause of Death Register. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using stratified and multivariable-adjusted Cox regression models. During a median follow-up of 8.8 years, 670 patients (44%) died, with the majority of deaths attributed to lymphoma (86%). Current versus never smoking at diagnosis was associated with increased rate of all-cause death for all NHL (HR = 1.5, 1.2-1.8) and diffuse large B-cell lymphoma (HR = 1.8, 1.2-2.7). Low educational level (HR = 1.3, 1.1-1.7, <9 vs. >12 years) and NHL risk-associated autoimmune disease (HR = 1.4, 1.0-1.8) were associated with death for all NHL combined. However, evidence of an association with lymphoma-related death was limited. Body mass index, recent sunbathing and family history of hematopoietic malignancy were not consistently associated with death after NHL or its specific subtypes. These results add to the evidence that cigarette smoking, socioeconomic status and certain autoimmune diseases affect survival after NHL. Further investigations are needed to determine how these factors should be incorporated into clinical prognostic assessment.

Systematic review with meta-analysis of the epidemiological evidence in the 1900s relating smoking to lung cancer

BACKGROUND

Smoking is a known lung cancer cause, but no detailed quantitative systematic review exists. We summarize evidence for various indices.

METHODS

Papers published before 2000 describing epidemiological studies involving 100+ lung cancer cases were obtained from Medline and other sources. Studies were classified as principal, or subsidiary where cases overlapped with principal studies. Data were extracted on design, exposures, histological types and confounder adjustment. RRs/ORs and 95% CIs were extracted for ever, current and ex smoking of cigarettes, pipes and cigars and indices of cigarette type and dose-response. Meta-analyses and meta-regressions investigated how relationships varied by study and RR characteristics, mainly for outcomes exactly or closely equivalent to all lung cancer, squamous cell carcinoma ("squamous") and adenocarcinoma ("adeno").

RESULTS

287 studies (20 subsidiary) were identified. Although RR estimates were markedly heterogeneous, the meta-analyses demonstrated a relationship of smoking with lung cancer risk, clearly seen for ever smoking (random-effects RR 5.50, CI 5.07-5.96) current smoking (8.43, 7.63-9.31), ex smoking (4.30, 3.93-4.71) and pipe/cigar only smoking (2.92, 2.38-3.57). It was stronger for squamous (current smoking RR 16.91, 13.14-21.76) than adeno (4.21, 3.32-5.34), and evident in both sexes (RRs somewhat higher in males), all continents (RRs highest for North America and lowest for Asia, particularly China), and both study types (RRs higher for prospective studies). Relationships were somewhat stronger in later starting and larger studies. RR estimates were similar in cigarette only and mixed smokers, and similar in smokers of pipes/cigars only, pipes only and cigars only. Exceptionally no increase in adeno risk was seen for pipe/cigar only smokers (0.93, 0.62-1.40). RRs were unrelated to mentholation, and higher for non-filter and handrolled cigarettes. RRs increased with amount smoked, duration, earlier starting age, tar level and fraction smoked and decreased with time quit. Relationships were strongest for small and squamous cell, intermediate for large cell and weakest for adenocarcinoma. Covariate-adjustment little affected RR estimates.

CONCLUSIONS

The association of lung cancer with smoking is strong, evident for all lung cancer types, dose-related and insensitive to covariate-adjustment. This emphasises the causal nature of the relationship. Our results quantify the relationships more precisely than previously.

Lifetime risk for cancer death by sex and smoking status: the lifetime risk pooling project

BACKGROUND

Understanding how sex and tobacco exposure may modify lifetime risks for cancer mortality is important for effective communication of risk in targeted public health messages.

OBJECTIVE

To determine lifetime risk estimates for cancer death associated with sex and smoking status in the United States.

METHODS

A pooled cohort design using ten well-defined epidemiologic cohorts including middle-aged and older individuals was used to estimate the lifetime risk for cancer death at selected index ages, with death from non-cancer causes as the competing risk, by sex and smoking status.

RESULTS

There were a total of 11,317 cancer-related deaths. At age 45 years, the lifetime risk of cancer death for male smokers is 27.7 % (95 % CI 24.0-31.4 %) compared to 15.8 % (95 % CI 12.7-18.9 %) for male non-smokers. At age 45 years, the lifetime risk of cancer death for female smokers is 21.7 % (95 % CI 18.8-24.6 %) compared to 13.2 % (95 % CI 11.0-15.4 %) for female non-smokers. Remaining lifetime risk for cancer death declined with age, and men have a greater risk for cancer death compared to women. Adjustment for competing risk of death, particularly representing cardiovascular mortality, yielded a greater change in lifetime risk estimates for men and smokers compared to women and non-smokers.

CONCLUSIONS

At the population level, the lifetime risk for cancer death remains significantly higher for smokers compared to non-smokers, regardless of sex. These estimates may provide clinicians with useful information for counseling individual patients and highlight the need for continued public health efforts related to smoking cessation.

Chapter 1:The impact of the reduction in tobacco smoking on U.S. lung cancer mortality, 1975-2000: an introduction to the problem

To better understand the contribution of cigarette smoking, and its changing role in lung cancer, this article provides an introduction to a special issue of Risk Analysis, which considers the relationship between smoking and lung cancer death rates during the period 1975-2000 for U.S. men and women aged 30-84 years. Six models are employed, which are part of a consortium of lung cancer modelers funded by National Cancer Institute's Cancer Intervention and Surveillance Modeling Network (CISNET). Starting with birth-cohort-specific smoking histories derived from National Health Interview Surveys, three scenarios are modeled: Actual Tobacco Control (observed trends in smoking), Complete Tobacco Control (a counterfactual lower bound on smoking rates that could have been achieved had all smoking ceased after the first Surgeon General's report in 1964), and No Tobacco Control (a counterfactual upper bound on smoking rates if smoking patterns that prevailed before the first studies in the 1950s began to inform the public about the hazards of smoking). Using these three scenarios and the lung cancer models, the number and percentage of lung cancer deaths averted from 1975-2000, among all deaths that could have been averted if tobacco control efforts been immediate and perfect, can be estimated. The variability of the results across multiple models provides a measure of the robustness of the results to model assumptions and structure. The results provide not only a portrait of the achieved impact of tobacco control on lung cancer mortality, but also the bounds of what still needs to be achieved.

Using the negative exponential distribution to quantitatively review the evidence on how rapidly the excess risk of ischaemic heart disease declines following quitting smoking

No previous review has formally modelled the decline in IHD risk following quitting smoking. From PubMed searches and other sources we identified 15 prospective and eight case-control studies that compared IHD risk in current smokers, never smokers, and quitters by time period of quit, some studies providing separate blocks of results by sex, age or amount smoked. For each of 41 independent blocks, we estimated, using the negative exponential model, the time, H, when the excess risk reduced to half that caused by smoking. Goodness-of-fit to the model was adequate for 35 blocks, others showing a non-monotonic pattern of decline following quitting, with a variable pattern of misfit. After omitting one block with a current smoker RR 1.0, the combined H estimate was 4.40 (95% CI 3.26-5.95) years. There was considerable heterogeneity, H being <2years for 10 blocks and >10years for 12. H increased (p<0.001) with mean age at study start, but not clearly with other factors. Sensitivity analyses allowing for reverse causation, or varying assumed midpoint times for the final open-ended quitting period little affected goodness-of-fit of the combined estimate. The US Surgeon-General's view that excess risk approximately halves after a year's abstinence seems over-optimistic.

Tendências do tabagismo na população adulta das capitais Brasileiras: uma análise dos dados de inquéritos telefônicos de 2006 a 2009

O objetivo deste estudo foi analisar a tendência do tabagismo, da cessação e da intensidade de cigarros diários, entre 2006 a 2009, nas capitais brasileiras. Foram analisados os dados de indivíduos com 18 anos e mais, entrevistados pelo Sistema de Vigilância e Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico (VIGITEL), realizado nas capitais brasileiras e Distrito Federal em 2006, 2007, 2008 e 2009. Para cada ano e grandes regiões, foram calculadas as prevalências de tabagismo ajustadas por idade e por grupos etários (18 a 29, 30 a 59 e 60 ou mais anos) estratificados por sexo. Foi calculado ainda o índice de cessação do tabagismo e, para os fumantes atuais, estimou-se a proporção dos que referem fumar 20 ou mais cigarros segundo sexo e grupo etário (18 a 39 e 40 anos e mais). Os resultados mostram leve tendência à queda do tabagismo entre homens e estabilidade para mulheres, com exceção daquelas residentes nas regiões Norte e Nordeste. Em geral, as maiores prevalências entre homens aparecem nos grupos mais jovens; enquanto que, entre as mulheres, são entre as de idade intermediária (30 a 59 anos). A cessação sugere estar ligeiramente aumentando entre os homens; há forte relação inversa entre a prevalência de tabagismo e anos de escolaridade, e a proporção de fumantes de 20 ou mais cigarros diários é maior entre os mais idosos e apresenta padrão diferenciado entre as regiões brasileiras. Os resultados indicam a necessidade da priorização de estratégias de controle do tabagismo que alcancem jovens e mulheres de baixa escolaridade.

Polonium and lung cancer

The alpha-radioactive polonium 210 (Po-210) is one of the most powerful carcinogenic agents of tobacco smoke and is responsible for the histotype shift of lung cancer from squamous cell type to adenocarcinoma. According to several studies, the principal source of Po-210 is the fertilizers used in tobacco plants, which are rich in polyphosphates containing radio (Ra-226) and its decay products, lead 210 (Pb-210) and Po-210. Tobacco leaves accumulate Pb-210 and Po-210 through their trichomes, and Pb-210 decays into Po-210 over time. With the combustion of the cigarette smoke becomes radioactive and Pb-210 and Po-210 reach the bronchopulmonary apparatus, especially in bifurcations of segmental bronchi. In this place, combined with other agents, it will manifest its carcinogenic activity, especially in patients with compromised mucous-ciliary clearance. Various studies have confirmed that the radiological risk from Po-210 in a smoker of 20 cigarettes per day for a year is equivalent to the one deriving from 300 chest X-rays, with an autonomous oncogenic capability of 4 lung cancers per 10000 smokers. Po-210 can also be found in passive smoke, since part of Po-210 spreads in the surrounding environment during tobacco combustion. Tobacco manufacturers have been aware of the alpha-radioactivity presence in tobacco smoke since the sixties.

Systematic review with meta-analysis of the epidemiological evidence relating smoking to COPD, chronic bronchitis and emphysema

BACKGROUND

Smoking is a known cause of the outcomes COPD, chronic bronchitis (CB) and emphysema, but no previous systematic review exists. We summarize evidence for various smoking indices.

METHODS

Based on MEDLINE searches and other sources we obtained papers published to 2006 describing epidemiological studies relating incidence or prevalence of these outcomes to smoking. Studies in children or adolescents, or in populations at high respiratory disease risk or with co-existing diseases were excluded. Study-specific data were extracted on design, exposures and outcomes considered, and confounder adjustment. For each outcome RRs/ORs and 95% CIs were extracted for ever, current and ex smoking and various dose response indices, and meta-analyses and meta-regressions conducted to determine how relationships were modified by various study and RR characteristics.

RESULTS

Of 218 studies identified, 133 provide data for COPD, 101 for CB and 28 for emphysema. RR estimates are markedly heterogeneous. Based on random-effects meta-analyses of most-adjusted RR/ORs, estimates are elevated for ever smoking (COPD 2.89, CI 2.63-3.17, n = 129 RRs; CB 2.69, 2.50-2.90, n = 114; emphysema 4.51, 3.38-6.02, n = 28), current smoking (COPD 3.51, 3.08-3.99; CB 3.41, 3.13-3.72; emphysema 4.87, 2.83-8.41) and ex smoking (COPD 2.35, 2.11-2.63; CB 1.63, 1.50-1.78; emphysema 3.52, 2.51-4.94). For COPD, RRs are higher for males, for studies conducted in North America, for cigarette smoking rather than any product smoking, and where the unexposed base is never smoking any product, and are markedly lower when asthma is included in the COPD definition. Variations by sex, continent, smoking product and unexposed group are in the same direction for CB, but less clearly demonstrated. For all outcomes RRs are higher when based on mortality, and for COPD are markedly lower when based on lung function. For all outcomes, risk increases with amount smoked and pack-years. Limited data show risk decreases with increasing starting age for COPD and CB and with increasing quitting duration for COPD. No clear relationship is seen with duration of smoking.

CONCLUSIONS

The results confirm and quantify the causal relationships with smoking.

Non-response bias in a surveillance program for asbestos-related lung cancer

OBJECTIVES

In a cohort study non-response might lead to a biased selection of cohort members and may affect the validity and reliability of the study outcome. To detect the possible effects of a non-response bias on study results, we evaluated the reasons for non-participation and the differences of respondents and non-respondents in a health surveillance program for power industry workers, formerly exposed to asbestos.

METHODS

A cohort of former power plant workers was formed to participate in an early detection program for lung cancer. We evaluated the results of 1,019 individuals (mean age 66 yr), of which 839 took part in at least one examination, 180 refused to participate or did not respond. To obtain the reasons for non-response, we interviewed the cohort members by telephone or we requested them by mail to complete and return a brief questionnaire. Further sources of information were the communal registration offices and local health offices.

RESULTS

The main reasons for non-participation were refusal (35%), illness (23.3%), death (16.7%) and difficulties with traveling (13.3%). It was impossible to make contact with or obtain an explanation from 11.7%. In a logistic regression model we demonstrated that advanced age and a long travel distance from the study center negatively affected the participation rate (p<0.001). There was no difference between respondents and non-respondents regarding prevalence (p=0.559) and incidence of lung cancer (p=0.882).

CONCLUSION

We concluded that in our cohort non-participation did not cause a selection bias in terms of lung cancer rates.

Is probability sampling always better? A comparison of results from a quota and a probability sample survey

Two surveys in the same defined population in Sydney's western suburbs in 1986 and 1987 provided the opportunity to compare results obtained from a quota and a probability sample survey. These surveys were designed to provide information for the planning of local health promotion programs. The quota sample survey was conducted in shopping centres and used quota sampling to select 1727 respondents. In the second survey, area probability sampling was used to select 484 respondents. This survey had a response rate of 65 per cent. There were 15 questions common to both surveys; results of only three differed significantly (p less than 0.05) between surveys. None of these differences was important from a public health perspective. The agreement between the results of these two surveys probably reflects the fact that the same selection bias has operated in both. Unless a very high response rate can be achieved, quota sample surveys with age and sex quota controls may be an acceptable alternative to probability sample surveys for gathering local data relevant to the development of health programs.

Breed, gender and neutering status of British dogs with anal sac gland carcinoma

This study details the breed, gender and neutering status of a large cohort of British canine patients suffering from histologically confirmed anal sac gland carcinoma. Estimates of the relative risk for the development of this disease attributable to these factors are calculated. To reduce the impact of sampling errors, cases were selected from veterinary histopathology laboratories rather than referral hospital databases, and multiple estimates of the general British canine population were used. The weaknesses of the statistical assumptions made are discussed. There was no evidence to support a gender predisposition for the development of this condition. English cocker spaniels are significantly over-represented, with a mean relative risk estimate of 7.3. The mean relative risk estimate associated with being neutered was 1.4; the effect of neutering appeared to be more significant in male dogs compared with that in female dogs.

Using time-dependent covariate analysis to elucidate the relation of smoking history to Warthin's tumor risk

The authors aimed to elucidate the relation of the time-dependent smoking history parameters--age at smoking initiation and smoking intensity, duration, and latency--to the risk of Warthin's tumor, a benign tumor of the salivary gland for which cigarette smoking is a strong risk factor. They studied 117 cases of Warthin's tumor and 336 matched controls included in an Israeli nationwide case-control study of parotid gland tumors conducted from 2002 to 2003 by using the Cox regression model with time-dependent covariates, with age as the time axis. When current age and smoking duration were included in the statistical model, the authors show that the coefficient of a latency variable does not represent latency as such, but a balancing of the effects of age at initiation and time since cessation. They found a strong positive linear effect of duration of smoking, together with a positive nonlinear effect of intensity that levels off at higher intensities, and a negative effect of latency from 25 years onward. The latter finding implies that the effect of time since cessation dominates the effect of age at initiation, with risk decreasing sharply after smoking cessation. The relation of smoking variables to Warthin's tumor agrees with the patterns reported for lung cancer.

Non-participants in a general population study of men, with special reference to social and alcoholic problems

The bias introduced by non-participation in a study depends on the size and the composition of the non-participant group. Out of 10,000 men invited to a screening examination in a large primary prevention trial in Göteborg, Sweden, 25% did not come to the examination. The non-participants could be shown to be registered by the Board of Social Welfare for social problems and alcohol abuse to a greater extent than the participants in the study. The annual mortality among the non-participants was about twice that of the participants during the entire follow-up period of 11.8 years. The incidence of non-fatal myocardial infarction was not significantly higher in non-participants. Coronary death, on the other hand, was significantly more common among those not attending the examination (3.5 vs. 7.6%). Participants registered for alcoholic problems had coronary death rates approaching those of the non-participants. Sudden coronary death accounted for most of the excess coronary mortality. Most of the excess mortality in the non-participant group was from other causes than cardiovascular diseases and cancer but even so, about one third of the excess deaths could be attributed to coronary heart disease. Possible explanations of this excess coronary mortality include that non-participants may smoke more, more frequently have alcoholic problems and that non-participation may reflect an unwillingness to seek medical care even in the event of illness.

Non-response to baseline, non-response to follow-up and mortality in the Whitehall II cohort

BACKGROUND

Little is known about the associations between non-response to follow-up surveys and mortality, or differences in these associations by socioeconomic position in studies with repeat data collections.

METHODS

The Whitehall II study of socioeconomic inequalities in health provided response status from five data collection surveys; Phase 1 (1985-88, n = 10 308), Phase 5 (1997-99, n = 6533), and all-cause mortality to 2006. Odd-numbered phases included a medical examination in addition to a questionnaire.

RESULTS

Non-response to baseline and to follow-up phases that included a medical examination was associated with a doubling of the mortality hazard in analyses adjusted for age and sex. Compared with complete responders, responders who missed one or more phases, but completed the last possible phase before they died, had a 38% excess risk of mortality. However, those who missed one or more phases including the last possible phase before death had an excess risk of 127%. There was no evidence that these associations differed by socioeconomic position.

CONCLUSION

In studies with repeat data collections, non-response to follow-up is associated with the same doubling of the mortality risk as non-response to baseline; an association that is not modified by socioeconomic position.