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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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.</p> <p>Conclusions</p> <p>The results confirm and quantify the causal relationships with smoking.</p

Influence of heavy traffic, city dwelling and socio-economic status on nasal symptoms assessed in a postal population survey

AbstractBackground: The association between social position, living environment and nasal symptoms is inconsistent. We wanted to test how living environment, occupation and social position were associated with nasal symptoms. Methods: In a postal survey study of a random sample of 12,079 adults, aged 20–59 years living in the southern part of Sweden the relationship between nasal symptoms, socio-economic status and environmental factors was analysed. Results: The response rate was 70% (n=8469) of whom 33% reported significant nasal symptoms. Nasal discharge, thick yellow discharge, a blocked nose, sneezing and itching were strongly associated with living close to heavy traffic or living in cities Most of the nasal symptoms provoked by extrinsic factors were more frequently reported among subjects who lived close to heavy traffic and in cities. Apart from thick yellow discharge and nasal symptoms provoked by damp/cold air which were more common in the socio-economic position “low” no relation to the socio-economic group was found. The prevalence of self-reported hay fever was neither affected by site of living nor by socio-economic status. Nasal symptoms evoked by “allergic” factors were linked to asthma but symptoms evoked by non-allergic factors were linked to chronic bronchitis/emphysema CBE. Conclusions: To conclude, we found a strong relation between geographical site and the prevalence of self-reported nasal symptoms which emphasizes the environment as a risk factor for nasal symptoms. Only by merging the socio-economic groups into “low” and “middle/high” an association to nasal symptoms was apparent. Nasal symptoms evoked by “allergic” factors were linked to asthma but symptoms evoked by “non allergic factors” were linked to CBE

Prevalence of obstructive lung diseases and respiratory symptoms in relation to living environment and socio-economic group

We wanted to test whether living environment, occupation and social position are risk factors for asthma and chronic bronchitis/emphysema (CBE). The prevalence of bronchial asthma, CBE, respiratory symptoms and smoking habits in a random sample of 12,071 adults aged 20-59 years was assessed in a postal survey with a slightly modified questionnaire previously used in central and northern Sweden (The OLIN studies). Occupation was coded according to a socio-economic classification system. Six different living environment areas were defined; city-countryside, seaside-not seaside and living close to heavy traffic-not living close to heavy traffic. Multiple logistic regression analysis (forward conditional) was applied to estimate the association between the proposed set of risk factors and self-reported obstructive lung diseases and lower respiratory symptoms controlling for age, gender and smoking. After two reminders, the response rate was 70.1% (n=8469); 33.8% of the responders were smokers. In all, 469 subjects (5.5%) stated that they had asthma and 4.6% reported CBE. Besides smoking, which was a risk for both asthma and CBE, there were different risk patterns for self-reported asthma and CBE. In the economically active population there was a tendency that CBE was more common among 'unskilled and semi-skilled workers'. This fact was further emphasized when the population was merged into the two groups 'low social position' and 'middle/high social position', with 'low social position' as a risk for CBE (OR=1.35, 95% CI=1.06-1.72). No social risk factors were identified for asthma. Living close to heavy traffic was a risk factor for asthma (OR=1.29, 95% CI=1.02-1.62) but not for CBE. Apart from this no living environmental risk factors for obstructive pulmonary diseases were identified. Asthma symptoms and long-standing cough were more common among those subjects living close to heavy traffic compared to those not living close to heavy traffic. To conclude, low social position was a risk factor for CBE and living close to heavy traffic was a risk factor for asthma

Cigarette smoking gives more respiratory symptoms among women than among men The Nord-Trøndelag Health Study (HUNT)

STUDY OBJECTIVE—Studies have indicated that women are more vulnerable to the effect of tobacco smoking compared with men. The aim of this study was to explore the prevalence of reported respiratory symptoms and diseases according to smoking burden, age and sex.
DESIGN—Questionnaire in a cross sectional population based study.
SETTING—The BONT (Bronchial obstruction in Nord-Trøndelag) study is part of a comprehensive health survey of all inhabitants aged above 19 years in the county of Nord-Trøndelag, Norway, which was carried out from 1995 to 1997.
PARTICIPANTS—A total of 65 717 subjects, 71.3% of the total population aged 20-100, answered the main questionnaire.
MAIN RESULTS—In all, 12.7% men and 12.1% women reported episodes of wheezing or breathlessness during the past 12 months, 8.8% men and 8.4% women reported that they had or had had asthma, 7.5% men and 8.2% women had ever used asthma medication, and 4.0% men and 3.0% women reported chronic bronchitis. Thirty per cent of men and 31% of women were smokers, and average pack years of smoking were 15.9 and 10.3, respectively. Among previous and current smokers, significant more women reported episodes of wheezing or breathlessness, current asthma and persistent coughing compared with men with the same smoke burden (pack years) and daily number of cigarettes.
CONCLUSION—The prevalence of reported asthma and use of asthma medication was higher than reported in previous Scandinavian studies. Respiratory symptoms increased by smoking burden. Comparing the prevalence of symptoms and current asthma among women and men with the same smoke burden or daily cigarette consumption, women seemed to be more susceptible to the effect of tobacco smoking than men.


Keywords: asthma; chronic bronchitis; coughing; tobacco smokin

The Impact of Chronic Cough:A Cross-Sectional European Survey

PURPOSE: Studies that investigate the impact of chronic cough have largely focused on patients attending secondary care. Our aim was to investigate the opinions of the wider general population across Europe. METHODS: An internet survey was made available in 12 languages on the European Lung Foundation website, between January 2012 and April 2013. RESULTS: Of 1120 respondents from 29 different European countries, 67 % were female, mean age 51 years (SD 15), median cough duration 2-5 years. The majority of respondents reported cough impacted their quality of life, mood and ability to undertake activities. Despite 72 % of respondents having visited their doctor ≥3 times, only 53 % had received a diagnosis. Asthma was the most common diagnosis (23 %). Most respondents reported limited or no effectiveness of medications. 88 % of respondents reported that they would like more information to be available on chronic cough. CONCLUSIONS: Chronic cough has a negative impact on quality of life. Further work is needed to raise awareness, promote management strategies, develop effective treatments and consider the educational and support needs of patients with chronic cough