Prevalence and risk factors for asthma and chronic bronchitis in the capitals Helsinki, Stockholm, and Tallinn

Interaction of smoking and social status on the risk of respiratory outcomes in a Swedish adult population: A Nordic Epilung study

BACKGROUND

Evidence abounds on the independent roles of social class and smoking in relation to obstructive airway diseases, but data are sparse on the impact of their interaction. We evaluated whether and to what extent social class and smoking interact in relation to risk of respiratory diseases in adults.

METHODS

Data from the population-based studies, West Sweden Asthma Study (WSAS, n = 23,753) and Obstructive Lung Disease in Northern Sweden studies (OLIN, n = 6519), were used, constituting randomly selected adults aged 20-75 years. Bayesian network analysis was used to estimate the probability for the interaction between smoking and socioeconomic status in relation to respiratory outcomes.

RESULTS

Occupational and educational SES modified the association between smoking and the probability of allergic and non-allergic asthma. Former smokers who were at intermediate non manual employees and manual workers in service had higher probability of allergic asthma compared to professionals and executives. Furthermore, former smokers with primary education had higher probability of non-allergic asthma than those with secondary and tertiary education. Similarly, former smokers among professionals and executives had higher probability of non-allergic asthma than manual and home workers and primary educated. Likewise, allergic asthma due to former smoking was higher among highly educated compared to low educated.

CONCLUSIONS

Beyond their independent roles, socioeconomic status and smoking interact in defining the risk of respiratory diseases. Clearer understanding of this interaction can help to identify population subgroups at most need of public health interventions.

Occupation, socioeconomic status and chronic obstructive respiratory diseases - The EpiLung study in Finland, Estonia and Sweden

OBJECTIVE

To study occupational groups and occupational exposure in association with chronic obstructive respiratory diseases.

METHODS

In early 2000s, structured interviews on chronic respiratory diseases and measurements of lung function as well as fractional expiratory nitric oxide (F_ENO) were performed in adult random population samples of Finland, Sweden and Estonia. Occupations were categorized according to three classification systems. Occupational exposure to vapours, gases, dusts and fumes (VGDF) was assessed by a Job-Exposure Matrix (JEM). The data from the countries were combined.

RESULTS

COPD, smoking and occupational exposure were most common in Estonia, while asthma and occupations requiring higher educational levels in Sweden and Finland. In an adjusted regression model, non-manual workers had a three-fold risk for physician-diagnosed asthma (OR 3.18, 95%CI 1.07-9.47) compared to professionals and executives, and the risk was two-fold for healthcare & social workers (OR 2.28, 95%CI 1.14-4.59) compared to administration and sales. An increased risk for physician-diagnosed COPD was seen in manual workers, regardless of classification system, but in contrast to asthma, the risk was mostly explained by smoking and less by occupational exposure to VGDF. For F_ENO, no associations with occupation were observed.

CONCLUSIONS

In this multicenter study from Finland, Sweden and Estonia, COPD was consistently associated with manual occupations with high smoking prevalence, highlighting the need to control for tobacco smoking in studies on occupational associations. In contrast, asthma tended to associate with non-manual occupations requiring higher educational levels. The occupational associations with asthma were not driven by eosinophilic inflammation presented by increased F_ENO.

Assessment of chronic bronchitis and risk factors in young adults: results from BAMSE

Background

Chronic bronchitis is associated with substantial morbidity among elderly adults, but little is known about its prevalence and risk factors in young adults. Our aim was to assess the prevalence and early-life risk factors for chronic bronchitis in young adults.

Methods

Questionnaire data and clinical measures from the 24-year follow-up of the Swedish BAMSE (Child (Barn), Allergy, Milieu, Stockholm, Epidemiological) cohort were used. We assessed chronic bronchitis (CB) as the combination of cough and mucus production in the morning during winter. Environmental and clinical data from birth and onwards were used for analyses of risk factors.

Results

At the 24-year follow-up, 75% (n=3064) participants completed the questionnaire and 2030 performed spirometry. The overall prevalence of CB was 5.5% (n=158) with similar estimates in males and females. 49% of CB cases experienced more than three self-reported respiratory infections in the past year compared to 18% in non-CB subjects (p<0.001), and 37% of cases were current smokers (versus 19% of non-CB cases). Statistically significant lower post-bronchodilator forced expiratory volume in 1 s/forced vital capacity were observed in CB compared to non-CB subjects (mean z-score −0.06 versus 0.13, p=0.027). Daily smoking (adjusted (a)OR 3.85, p<0.001), air pollution exposure (black carbon at ages 1–4 years aOR 1.71 per 1 μg·m⁻³ increase, p=0.009) and exclusive breastfeeding for ≤4 months (aOR 0.66, p=0.044) were associated with CB.

Conclusion

Chronic bronchitis in young adults is associated with recurrent respiratory infections. Besides smoking, our results support the role of early-life exposures, such as air pollution and exclusive breastfeeding, for respiratory health later in life.

Chronic bronchitis in young adults is strongly associated with recurrent respiratory infections. Besides smoking, our results support the role of early-life environmental exposures for respiratory health in this age group.https://bit.ly/2RNsv5z

Differences in diagnostic patterns of obstructive airway disease between areas and sex in Sweden and Finland - the Nordic EpiLung study

OBJECTIVE

To investigate the current prevalence of physician-diagnosed obstructive airway diseases by respiratory symptoms and by sex in Sweden and Finland.

METHOD

In 2016, a postal questionnaire was answered by 34,072 randomly selected adults in four study areas: Västra Götaland and Norrbotten in Sweden, and Seinäjoki-Vaasa and Helsinki in Finland.

RESULTS

The prevalence of asthma symptoms was higher in Norrbotten (13.2%), Seinäjoki-Vaasa (14.8%) and Helsinki (14.4%) than in Västra Götaland (10.7%), and physician-diagnosed asthma was highest in Norrbotten (13.0%) and least in Västra Götaland (10.1%). Chronic productive cough was most common in the Finnish areas (7.7-8.2% versus 6.3-6.7%) while the prevalence of physician-diagnosed chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) varied between 1.7 and 2.7% in the four areas. Among individuals with respiratory symptoms, the prevalence of asthma was most common in Norrbotten, while a diagnosis of COPD or CB was most common in Västra Götaland and Seinäjoki-Vaasa. More women than men with respiratory symptoms reported a diagnosis of asthma in Sweden and Seinäjoki-Vaasa but there were no sex differences in Helsinki. In Sweden, more women than men with symptoms of cough or phlegm reported a diagnosis of CB or COPD, while in Finland the opposite was found.

CONCLUSION

The prevalence of respiratory symptoms and corresponding diagnoses varied between and within the countries. The proportion reporting a diagnosis of obstructive airway disease among individuals with respiratory symptoms varied, indicating differences in diagnostic patterns both between areas and by sex.

The Finnish experience to save asthma costs by improving care in 1987-2013

The Finnish National Asthma Program 1994-2004 markedly improved asthma care in the 1990s. We evaluated the changes in costs during 26 years from 1987 to 2013. Direct and indirect costs were calculated by using data from national registries. Costs from both the societal and patient perspectives were included. The costs were based on patients with persistent, physician-diagnosed asthma verified by lung function measurements. We constructed minimum and maximum scenarios to assess the effect of improved asthma care on total costs. The number of patients with persistent asthma in the national drug reimbursement register increased from 83,000 to 247,583. Improved asthma control reduced health care use and disability, resulting in major cost savings. Despite a 3-fold increase in patients, the total costs decreased by 14%, from €222 million to €191 million. Costs for medication and primary care visits increased, but overall annual costs per patient decreased by 72%, from €2656 to €749. The theoretical total cost savings for 2013, comparing actual with predicted costs, were between €120 and €475 million, depending on the scenario used. The Finnish Asthma Program resulted in significant cost savings at both the societal and patient levels during a 26-year period.

No change in prevalence of symptoms of COPD between 1996 and 2006 in Finnish adults - a report from the FinEsS Helsinki Study

BACKGROUND

The age-dependent increase of chronic obstructive pulmonary disease (COPD) prevalence caused by smoking and other inhalational exposures in the general population is well-known worldwide. However, time trends are poorly known, due to lower number of high-quality studies especially following nationwide efforts on diminishing exposure levels. This study aimed to compare the prevalence of COPD symptoms and their major determinants in Finnish adults in 1996 and 2006.

METHODS

Two identical postal surveys were conducted among two random population samples from Helsinki using identical methodologies in 1996 and 2006, with 6,062 (76%) and 2,449 (62%) participants, respectively.

RESULTS

The physician-diagnoses of COPD remained at 3.7%, whereas physician-diagnoses of asthma and use of asthma medicines increased in both genders. Current smoking reduced from 33.4 to 27.3% (p<0.001), and the amount of cigarettes smoked also reduced significantly. The crude prevalence of chronic productive cough was 12.1 and 11.1%, wheezing with dyspnoea without a cold (wheezing triad) 7.3 and 7.7%, and dyspnoea grade II 13.8 and 13.6%, in 1996 and 2006, respectively. Among subjects with physician-diagnosed COPD, the prevalences of chronic productive cough and recurrent wheeze reduced significantly, from 60.6 to 40.7% and 53.5 to 38.5%, respectively.

CONCLUSION

From 1996 to 2006, the prevalence of obstructive airway symptoms common in different phenotypes of COPD did not increase in Finnish adults. This suggests that the upward trend of COPD prevalence might have reached a plateau. Current smoking and the quantities smoked diminished suggesting a wider impact of stronger legislation and smoking-cessation efforts during the Finnish National Programme for COPD.

Respiratory symptoms increase health care consumption and affect everyday life - a cross-sectional population-based study from Finland, Estonia, and Sweden

BACKGROUND

Even though respiratory symptoms are common in the adult population, there is limited research describing their impact on everyday life and association with health care consumption.

AIM

The main objective of this population-based study was to estimate and compare the prevalence of respiratory symptoms among adults in Finland, Estonia, and Sweden in relation to health care consumption and to identify factors influencing health care consumption. A secondary aim was to assess to which extent the presence of respiratory symptoms affect everyday life.

METHOD

In the population-based FinEsS studies consisting of random samples of subjects aged 20 to 69 years from Finland (n=1,337), Estonia (n=1,346), and Sweden (n=1,953), data on demographics, respiratory health, and health care consumption were collected by structured interviews. Prevalence was compared and multiple logistic regression analyses were performed.

RESULTS

Respiratory symptoms were significantly more common in Finland (66.0%) and Estonia (65.2%) than in Sweden (54.1%). Among subjects with respiratory symptoms, the proportion reporting outpatient care during the past year was fairly similar in the three countries, while specialist consultations were more common in Finland (19.1%), and hospitalisations more common in Estonia (15.0%). Finnish and Estonian residency, female sex, and BMI>25 increased the risk for outpatient care consumption. Wheeze and attacks of shortness of breath in the past 12 months, recurrent sputum production, and cough were associated with an increased risk for health care consumption. Increasing number of respiratory symptoms increased the risk for consuming health care. A larger proportion of subjects in Estonia and Sweden experienced their everyday life being affected by respiratory symptoms compared with subjects in Finland.

CONCLUSION

Respiratory symptoms are common in Finland, Estonia, and Sweden and contribute to a negative impact on everyday life as well as increased health care consumption. The observed differences in health care consumption between countries are probably related to national differences in health care structure.

Defining Chronic Cough: A Systematic Review of the Epidemiological Literature

Purpose

Recent evidence suggests a global burden of chronic cough in general populations. However, the definitions vary greatly among epidemiological studies, and none have been validated for clinical relevance. We aimed to examine previous epidemiological definitions in detail and explore the operational characteristics.

Methods

A systematic review was conducted for epidemiological surveys that reported the prevalence of chronic cough in general adult populations during the years 1980 to 2013. A literature search was performed on Pubmed and Embase without language restriction. Epidemiological definitions for chronic cough were classified according to their components, such as cutoff duration. Meta-analyses were performed for the male-to-female ratio of chronic cough prevalence to explore operational characteristics of epidemiological definitions.

Results

A total of 70 studies were included in the systematic review. The most common epidemiological definition was identified as 'cough ≥3 months' duration without specification of phlegm (n=50); however, it conflicted with the cutoff duration in current clinical guidelines (cough ≥8 weeks). Meta-analyses were performed for the male-to-female ratio of chronic cough among 28 studies that reported sex-specific prevalence using the most common definition. The pooled male-to-female odds ratio was 1.26 (95% confidence interval 0.92-1.73) with significant heterogeneity (I²=96%, P<0.001), which was in contrast to clinical observations of female predominance from specialist clinics. Subgroup analyses did not reverse the ratio or reduce the heterogeneity.

Conclusions

This study identified major issues in defining chronic cough in future epidemiological studies. The conflict between epidemiological and clinical diagnostic criteria needs to be resolved. The unexpected difference in the gender predominance between the community and clinics warrants further studies. Clinical validation of the existing definition is required.

Frequent cough in unsatisfactory controlled asthma--results from the population-based West Sweden Asthma study

BACKGROUND

Asthma is a complex disease presenting with variable symptoms which are sometimes hard to control. The purpose of the study was to describe the prevalence of asthma symptoms, use of asthma medications and allergic sensitization in subjects with asthma. We also related those indices to the level of asthma control, lung function and in particular, cough.

METHODS

An extensive questionnaire was sent to randomly selected adults from the West Sweden region. Clinical examinations and interview were performed in a subset. Of the participants, 744 were defined as having an ongoing asthma - reported ever having asthma or physician diagnosed asthma and one of the following - use of asthma medications, recurrent wheeze or attacks of shortness of breath with or without wheeze in the last 12 months. A respiratory disease-free control group of 847 subjects was also described.

RESULTS

According to GINA guidelines, 40.6% of the asthmatics had partly controlled and 17.8% had uncontrolled asthma. Asthmatic subjects reported significantly more symptoms in the last 12 months than the control group - wheezing (79.4 vs 9.2%), shortness of breath (36.1 vs 2.5%), wheezing with shortness of breath (58.7 vs 1.3%). Important complaints were morning cough (42.5 vs 15.5%), cough with sputum production (36.1 vs 6.8%) and longstanding cough (32.5 vs 11.1%), which bothered two thirds of the uncontrolled and one third of partly controlled subjects. Asthma medications were used by 87.5% of the asthmatics, although around 30% of them who had insufficiently controlled disease used only short-acting beta-agonists. Asthmatics also had lower lung function, reacted to lower doses of methacholine that the controls and 13.6% of them had a FEV1/FVC ratio below 0.7. Allergic rhinitis was reported by 73.8% of the asthmatics and they were more frequently sensitized to several common allergens.

CONCLUSIONS

Approximately 60% of asthmatics from this population-based study had insufficiently controlled asthma and persistent complaints, despite a high use of asthma medications. These self-reported symptoms were supported by clinical examination data. Increased cough frequency is an indicator of a more severe and difficult to control disease and should be considered when asthma is characterized.

Curative effect of heat-sensitive moxibustion on chronic persistent asthma: a multicenter randomized controlled trial

OBJECTIVE

To compare the curative effects of heat-sensitive moxibustion with conventional drugs on chronic persistent asthma and seek a valuable therapy to replace Western Medicine.

METHODS

The participants in this multi-center, randomized, and controlled study were randomly divided into two groups: group A (n=144), treated with heat-sensitive moxibustion (50 sessions) and group B (n=144), treated with Seretide (salmeterol 50 plg/fluticasone 250 pg, twice a day). The scores of asthma control test (ACT), forced expiratory volume in 1 second (FEV1), peak expiratory flow (PEF), and attack frequency were measured after 15, 30, 60, and 90 days of treatment. Patients followed up 3 and 6 months after treatment.

RESULTS

There was a significant difference (P= 0.0002) in the ACT score and lung function between the two groups after 3 months of treatment and (P=0.000 03) during the follow-up visits. In addition, heat-sensitive moxibustion reduced attack frequency in the period from inclusion to the 6-month follow-up visit.

CONCLUSION

This study shows that heat-sensitive moxibustion may have a comparable curative effect to Seretide (salmetero/fluticasone) on asthma.

Prevalence trends in respiratory symptoms and asthma in relation to smoking - two cross-sectional studies ten years apart among adults in northern Sweden

Background

Smoking is considered to be the single most important preventable risk factor for respiratory symptoms. Estimating prevalence of respiratory symptoms is important since they most often precede a diagnosis of an obstructive airway disease, which places a major burden on the society. The aim of this study was to estimate prevalence trends of respiratory symptoms and asthma among Swedish adults, in relation to smoking habits. A further aim was to estimate the proportion of respiratory symptom and asthma prevalence attributable to smoking.

Methods

Data from two large-scale cross-sectional surveys among adults performed in northern Sweden in 1996 and 2006 were analysed. Identical methods and the same questionnaire were used in both surveys. The association between smoking, respiratory symptoms and asthma was analysed with multiple logistic regression analyses. Changes in prevalence of respiratory symptoms and asthma from 1996 to 2006 were expressed as odds ratios. Additionally, the population attributable risks of smoking were estimated.

Results

The prevalence of most respiratory symptoms decreased significantly from 1996 to 2006. Longstanding cough decreased from 12.4 to 10.1%, sputum production from 19.0 to 15.0%, chronic productive cough from 7.3 to 6.2%, and recurrent wheeze from 13.4 to 12.0%. Any wheeze and asthmatic wheeze remained unchanged. This parallels to a decrease in smoking from 27.4 to 19.1%. In contrast, physician-diagnosed asthma increased from 9.4 to 11.6%. The patterns were similar after correction for confounders. All respiratory symptoms were highly associated with smoking, and the proportion of respiratory symptoms in the population attributed to smoking (PAR) ranged from 9.8 to 25.5%. In 2006, PAR of smoking was highest for recurrent wheeze (20.6%).

Conclusions

In conclusion, we found that respiratory symptoms, in particular symptoms common in bronchitis, decreased among adults in northern Sweden, parallel to a decrease in smoking from 1996 to 2006. In contrast, the prevalence of physician-diagnosed asthma increased during the same time-period. Up to one fourth of the respiratory symptom prevalence in the population was attributable to smoking.

Alarmingly high prevalence of smoking and symptoms of bronchitis in young women in Sweden: a population-based questionnaire study

BACKGROUND

After 10 years of a decrease in smoking among young people in Sweden, we now have indications of increased smoking.

AIMS

To provide up-to-date information on the prevalence of smoking and smoke-associated respiratory symptoms in young adults in Sweden, with a special focus on possible gender differences.

METHODS

In the West Sweden Asthma Study, a detailed postal questionnaire focusing on asthma, respiratory symptoms, and possible risk factors was mailed to 30,000 randomly selected subjects aged 16-75 years. The analyses are based on responses from 2,702 subjects aged 16-25 years.

RESULTS

More young women than men were smokers (23.5% vs. 15.9%; p<0.001). Women started smoking earlier and smoked more. Symptoms such as longstanding cough, sputum production, and wheeze were significantly more common in smokers. In the multiple logistic regression analysis, smoking significantly increased the risk of recurrent wheeze (odds ratio (OR) 2.0 (95% CI 1.4 to 3.0)) and sputum production, (OR 2.4 (95% CI 1.9 to 3.1)).

CONCLUSIONS

The alarmingly high prevalence of smoking among young women was parallel to a similarly high prevalence of bronchitis symptoms. This is worrisome, both in itself and because maternal smoking is a risk factor for illness in the child. Adverse respiratory effects of smoking occur within only a few years of smoking initiation.

Increase in prevalence of physician-diagnosed asthma in Helsinki during the Finnish Asthma Programme: improved recognition of asthma in primary care? A cross-sectional cohort study

BACKGROUND

The continuing rise in asthma prevalence has been questioned, with recent reports suggesting a plateau.

AIMS

To assess a 10-year trend in the age-adjusted prevalence of physician-diagnosed asthma, respiratory and allergic symptoms, and use of asthma medication in the adult population of Helsinki during the Finnish Asthma Programme from 1994 to 2004.

METHODS

Two cross-sectional postal surveys were conducted among random Finnish National Population Registry samples 10 years apart using the same protocol. A total of 6,062 subjects (75.9%) and 2,449 subjects (61.9%) participated in 1996 and 2006, respectively.

RESULTS

The prevalence of physician-diagnosed asthma increased from 6.5% in 1996 to 10.0% in 2006 (p<0.001). This was evident in both genders aged <60 years, but particularly in women aged <40 years, paralleling an increased use of asthma medication. Concurrently, the prevalence of allergic rhinoconjunctivitis increased from 37.2% to 44.4% (p<0.001). The prevalence of physician-diagnosed chronic obstructive pulmonary disease remained unchanged (3.7%), while current smoking abated. Subjects with a smoking history had more respiratory symptoms (p<0.001). Among subjects without physician-diagnosed asthma, those reporting allergic rhinoconjunctivitis had a higher prevalence of lower respiratory tract symptoms.

CONCLUSIONS

The prevalence of allergic rhinoconjunctivitis and physician-diagnosed asthma has increased in Helsinki during 10 years in adults, especially in women aged <40 years. Concomitantly, the use of asthma medication increased and subjects with physiciandiagnosed asthma were less symptomatic. The increase in the prevalence of physician-diagnosed asthma may partly be due to improved diagnostic recognition of asthma in primary care during the Finnish Asthma Programme, but the concurrent rise in allergic rhinoconjunctivitis may reflect a true rise in prevalence.

Asthma/COPD drugs reflecting disease prevalence, patient adherence and persistence

The aim of this review is to discuss the methodological issues involved in using pharmacy-record databases of drug sales in pharmacoepidemiology and to illustrate the usefulness of such data in estimating disease prevalence, patient adherence and persistence to therapy. Recent studies show that asthma/chronic obstructive pulmonary disease (COPD) prevalence increases with age. The volume of acquired asthma/COPD drugs per patient also increases with age and was approximately 2.5-times higher for patients aged 60-69 years compared with patients aged 20-29 years. Despite this, there is a comparatively low interest in asthma/COPD research involving elderly individuals. Published asthma/COPD-prevalence data and drug-treatment-prevalence data correspond reasonably well. Short- as well as long-term studies on drug acquisition indicate that approximately a third of patients have drugs available to cover at least 80% of the prescribed treatment time. Only approximately a tenth of the patients acquired steroids or steroid combinations, corresponding to one daily defined dose per day over a 5-year treatment period. It is probable that asthma/COPD is undertreated in all age groups.

Epidemiology of chronic obstructive pulmonary disease: a literature review

The aim of this study is to quantify the burden of chronic obstructive pulmonary disease (COPD) – incidence, prevalence, and mortality – and identify trends in Australia, Canada, France, Germany, Italy, Japan, The Netherlands, Spain, Sweden, the United Kingdom, and the United States of America. A structured literature search was performed (January 2000 to September 2010) of PubMed and EMBASE, identifying English-language articles reporting COPD prevalence, incidence, or mortality. Of 2838 articles identified, 299 full-text articles were reviewed, and data were extracted from 133 publications. Prevalence data were extracted from 80 articles, incidence data from 15 articles, and mortality data from 58 articles. Prevalence ranged from 0.2%–37%, but varied widely across countries and populations, and by COPD diagnosis and classification methods. Prevalence and incidence were greatest in men and those aged 75 years and older. Mortality ranged from 3–111 deaths per 100,000 population. Mortality increased in the last 30–40 years; more recently, mortality decreased in men in several countries, while increasing or stabilizing in women. Although COPD mortality increased over time, rates declined more recently, likely indicating improvements in COPD management. In many countries, COPD mortality has increased in women but decreased in men. This may be explained by differences in smoking patterns and a greater vulnerability in women to the adverse effects of smoking.

Eczema among adults: prevalence, risk factors and relation to airway diseases. Results from a large-scale population survey in Sweden

BACKGROUND

In contrast to asthma and rhinitis, few studies among adults investigating the prevalence and risk factors of eczema have been published.

OBJECTIVES

To investigate the prevalence and risk factors of eczema among adults in West Sweden. A further aim was to study the associations between asthma, rhinitis and eczema.

METHODS

A questionnaire on respiratory health was mailed in 2008 to 30,000 randomly selected subjects in West Sweden aged 16-75 years; 62% responded. The questionnaire included questions about eczema, respiratory symptoms and diseases and their possible determinants. A subgroup of 669 subjects underwent skin prick testing against common airborne allergens.

RESULTS

'Eczema ever' was reported by 40·7% and 'current eczema' by 11·5%. Both conditions were significantly more common among women. The prevalence decreased with increasing age. The coexistence of both asthma and rhinitis with eczema was common. The main risk factors were family history of allergy and asthma. The dominant environmental risk factor was occupational exposure to gas, dust or fumes. Smoking increased the risk. Eczema was associated with urbanization, while growing up on a farm was associated with a decreased risk. Added one by one to the multivariate model, asthma, allergic rhinitis and any positive skin prick test were associated with eczema.

CONCLUSIONS

Eczema among adults is a common disease with more women than men having and having had eczema. Eczema is associated with other atopic diseases and with airway symptoms. Hereditary factors and exposure to gas, dust and fumes are associated with eczema.

The 10-year COPD Programme in Finland: effects on quality of diagnosis, smoking, prevalence, hospital admissions and mortality

BACKGROUND

The Finnish National Programme for Chronic Bronchitis and Chronic Obstructive Pulmonary Disease (COPD) 1998-2007 was set up to reduce the prevalence of COPD, improve COPD diagnosis and care, reduce the number of moderate to severe cases of the disease, and reduce hospitalisations and treatment costs due to COPD. Over 900 events for 25,000 participating healthcare workers were arranged. The major strengths of this programme included multidisciplinary strategies and web-based guidelines in nearly all primary health care centres around the country.

METHODS

Data from national registries, epidemiological studies and questionnaires were used to measure whether the goals had been reached.

RESULTS

The prevalence of COPD remained unchanged. Smoking decreased in males from 30% to 26% (p<0.001) and in females from 20% to 17% (p<0.001). Significant improvements in the quality of spirometry were obtained. Hospitalisation decreased by 39.7% (p<0.001). COPD costs were 88% lower than had been anticipated from earlier investigations. No increase in COPD mortality was observed.

CONCLUSIONS

In combination with other efforts, the Finnish 10-year COPD Programme had significant positive consequences: no further increases in COPD prevalence, reduced smoking prevalence, improved quality of diagnosis, and reduction in COPD-related hospitalisations.

Long-term results of esophageal atresia: Helsinki experience and review of literature

Esophageal atresia (EA) affects one in 2,840 newborns, and over half have associated anomalies that typically affect the midline. After EA repair in infancy, gastroesophageal reflux (GER) and esophageal dysmotility and respiratory problems are common. Significant esophageal morbidity associated with EA extends into adulthood. Surgical complications, increasing age, and impaired esophageal motility predict the development of epithelial metaplasia after repair of EA. To date, worldwide, six cases of esophageal cancer have been reported in young adults treated for EA. According to our data, the statistical risk for esophageal cancer is not higher than 500-fold that of the general population. However, the overall cancer incidence among adults with repaired EA does not differ from that of the general population. Adults with repaired EA have had significantly more respiratory symptoms and infections, as well as more asthma and allergies than does the general population. Nearly half the patients have bronchial hyperresponsiveness. Thoracotomy-induced rib fusion and gastroesophageal reflux-associated columnar epithelial metaplasia are the most significant risk factors for the restrictive ventilatory defect that occurs in over half the patients. Over half the patients with repaired EA are likely to develop scoliosis. Risk for scoliosis is 13-fold after repair of EA in relation to that of the general population. Nearly half of the patients have had vertebral anomalies predominating in the cervical spine, and of these, most were vertebral fusions. The natural history of spinal deformities seems, however, rather benign, with spinal surgery rarely indicated.

Update of prevalence of self-reported allergic rhinitis and chronic nasal symptoms among adults in Sweden

BACKGROUND

Allergic rhinitis (AR) is the most common immunologic disease, and it renders a considerable burden on both sufferers and society. The prevalence of AR has been increasing worldwide over the past century. The aim of this study was to assess the present prevalence, risk factor patterns and comorbidity of self-reported AR and chronic nasal symptoms in different age groups in Stockholm, Sweden.

METHODS

A postal questionnaire was sent on two occasions, in 2006 to a population aged 30-80 years, randomly selected 10 years previously, and in 2007 to a randomly selected sample of subjects aged 20-69 years. The response rates were 83% and 68%, respectively, and in total, 9792 subjects participated. The questionnaire included questions on self-reported AR, asthma, respiratory and nasal symptoms and possible determinants.

RESULTS

The prevalence of self-reported AR was 28.0% (men 26.6%, women 29.1%, P < 0.01) similar to 10 years previously and 33.6% in ages 30-40 years. Allergic heredity [odds ratio (OR) 4.76, confidence interval (CI) 95% 4.25-5.33], physician-diagnosed asthma (OR 5.29, CI 95% 4.49-6.24) and occupational exposure to dust, gases and fumes (OR 1.49, CI 95% 1.30-1.72) were determinants for AR. Prevalence of chronic nasal congestion was 16.1% and of chronic rhinorrhea 14.1%.

CONCLUSIONS

As a basis for understanding the disease, as well as in planning and prioritizing health-care resources, the study provides information about the current prevalence and determinants of self-reported AR and chronic nasal symptoms. Further, comparing with previous studies, the present study suggests that a plateau in the prevalence of AR may have been reached in Sweden.

Allergic rhinitis in northern vietnam: increased risk of urban living according to a large population survey

BACKGROUND

Little is known about prevalence and risk factors of allergic rhinitis and chronic nasal symptoms among adults in Vietnam. We aimed to estimate the prevalence, risk factor patterns and co-morbidities of allergic rhinitis and chronic nasal symptoms in one urban and one rural area in northern Vietnam.

METHODS

A cross-sectional questionnaire survey was conducted from August 2007 to January 2008 in urban Hoankiem and rural Bavi in Hanoi among adults aged 21-70 years. Of 7008 randomly selected subjects, 91.7% participated in Bavi and 70.3% in Hoankiem.

RESULTS

Allergic rhinitis ever or chronic nasal symptoms were reported by 50.2%. The prevalence of allergic rhinitis ever was considerably higher in Hoankiem compared to Bavi, 29.6% vs 10.0% (p < 0.001). Allergic rhinitis ever and chronic nasal symptoms were both significantly associated with asthma and respiratory symptoms, respectively (p < 0.001). Exposure to gas, dust or fumes at work was significantly associated with allergic rhinitis ever, OR 1.57 (95% CI 1.34 - 1.84), nasal blocking, OR 1.90 (95% CI 1.68 - 2.15) and runny nose, OR 1.32 (95% CI 1.17 - 1.49), while somewhat surprisingly no association with smoking was found. Female sex was a significant risk factor for both nasal blocking and runny nose.

CONCLUSIONS

Allergic rhinitis ever was considerably more common in the urban area. Nasal blocking and runny nose was each reported by about one third of the studied sample with no major urban-rural difference. Further, exposure to air pollution at work was significantly associated with allergic rhinitis ever, nasal blocking and runny nose.

Rhinitis phenotypes correlate with different symptom presentation and risk factor patterns of asthma

BACKGROUND

Asthma and rhinitis frequently coexist, but no population study has previously determined the relationship between nasal comorbidities and symptom expression and risk factors of asthma.

METHODS

In 2008, a postal questionnaire on respiratory health was sent to 30,000 randomly selected subjects aged 16-75 years in West Sweden; 29218 could be traced and 18,087 (62%) responded. The questionnaire included questions on asthma, rhinitis, chronic rhinosinusitis, respiratory symptoms and possible determinants.

RESULTS

Prevalence of allergic rhinitis in asthma was 63.9% and of asthma in allergic rhinitis 19.8%. Prevalence of chronic rhinosinusitis in asthma was 8.4% and of asthma in chronic rhinosinusitis 24.4%. Asthma subjects with chronic rhinitis, or chronic rhinosinusitis, had more symptoms of asthma and bronchitis than those without rhinitis (p < 0.001). There was an obvious trend of higher ORs for various environmental exposures including occupational exposure to dust, gases and fumes (OR 2.32 vs. OR 1.44), visible mould at home (OR 1.72 vs. OR 1.27) and water damage at home (OR 1.82 vs. OR 1.06) for asthma with chronic rhinosinusitis than for asthma with allergic rhinitis. Family history of allergy yielded a higher OR for asthma with allergic rhinitis than with asthma with chronic rhinosinusitis (OR 7.15 vs. OR 4.48).

CONCLUSION

Considerable overlap between asthma and nasal comorbidities was documented, confirming a close relationship between nasal disease and asthma. Allergic rhinitis, chronic rhinitis and chronic rhinosinusitis were associated with different risk factor patterns and symptom expression of asthma. Thus, different nasal comorbidities may reflect different phenotypes of asthma.

Asthma and chronic bronchitis symptoms among adult population of Belgrade

INTRODUCTION

Over the last three decades the prevalence of respiratory diseases has been increasing worldwide thus increasing economic burden on the healthcare system. Recent studies have shown that the prevalence of asthma in West European countries ranges from 6-9%, while of chronic obstructive pulmonary diseases (COPD) is 8.0% worldwide.

OBJECTIVE

The aim of the study was to estimate the prevalence of respiratory symptoms and smoking habits, and to assess the prevalence of asthma and chronic bronchitis among adults in Belgrade, Serbia.

METHODS

To collect data we used a questionnaire based on the European Community Respiratory Health Survey (ECRHS) protocol, which was mailed to 10,208 randomly selected subjects.

RESULTS

There were 58.3% of responders to our questionnaire. We noted a higher prevalence of respiratory symptoms in subjects who responded promptly. The majority of the respondents were current or former smokers (37.5% and 17.5% respectively) and 79.9% of them reported respiratory symptoms. The most frequent symptoms were longstanding cough (32.2%), sputum production (30.4%) and wheezing (30.3%). Asthma attacks were reported in 4.4% of cases and 5.6% of subjects were using asthma medications. The prevalence of respiratory symptoms increased with age. Women reported coughing, attacks of breathlessness and coughing, chest tightness by night, allergic rhinitis and chronic coughing, more frequently than men. Productive cough was more frequent in men. The prevalence of almost all symptoms was higher in smokers compared to nonsmokers.

CONCLUSION

In Serbia there is a high prevalence of respiratory symptoms, asthma and chronic bronchitis smoking addiction.

Nasal and ocular effects in foundry workers using the hot box method

OBJECTIVE

To investigate the prevalence of nasal and ocular symptoms and nasal signs in foundry workers exposed to monoisocyanates using the Hot Box method.

METHODS

Forty-three foundry workers and 69 referents completed questionnaires and were examined by a rhinologist. Exposure to isocyanic acid, methyl isocyanate, formaldehyde, and total dust was measured.

RESULTS

Nasal symptoms and signs were associated with exposure, and dose-response relationships between nasal symptoms and exposure to isocyanic acid, methyl isocyanate, and formaldehyde were observed. Dry nasal mucosa was more prevalent in exposed workers than in referents. These findings were not substantially affected by the exclusion of asthmatic and allergic individuals, smokers, or females.

CONCLUSIONS

An increased prevalence of nasal symptoms and signs was observed among exposed workers, suggesting an association with the foundry environment involving monoisocyanates and other airway irritants, such as formaldehyde and dust.

Multi-symptom asthma is closely related to nasal blockage, rhinorrhea and symptoms of chronic rhinosinusitis-evidence from the West Sweden Asthma Study

Background

We have previously shown that approximately 25% of those with asthma in West Sweden have multiple asthma symptoms, which may describe a group of patients with more severe disease. Furthermore, asthma is associated with several co-morbid diseases, including rhinitis and chronic rhinosinusitis. The aim of this study was to determine whether multi-symptom asthma is related to signs of severe asthma, and to investigate the association between multi-symptom asthma and different symptoms of allergic and chronic rhinosinusitis.

Methods

This study analyzed data on asthma symptoms, rhinitis, and chronic rhinosinusitis from the 2008 West Sweden Asthma Study, which is an epidemiologically based study using the OLIN and GA²LEN respiratory and allergy focused questionnaires.

Results

Multi-symptom asthma was present in 2.1% of the general population. Subjects with multi-symptom asthma had more than double the risk of having night-time awakenings caused by asthma compared with those with fewer asthma symptoms (P < 0.001). The prevalence of allergic rhinitis was similar in the fewer- and multi-symptom asthma groups, but nasal blockage and rhinorrhea were significantly increased in those with multi- versus fewer-symptom asthma (odds ratio 2.21; 95% confidence interval 1.64-2.97, versus 1.49; 1.10-2.02, respectively). Having any, or one to four symptoms of chronic rhinosinusitis significantly increased the risk of having multi- versus fewer-symptom asthma (P < 0.01).

Conclusion

An epidemiologically identified group of individuals with multiple asthma symptoms harbour to greater extent those with signs of severe asthma. The degree of rhinitis, described by the presence of symptoms of nasal blockage or rhinorrhea, as well as the presence of any or several signs of chronic rhinosinusitis, significantly increases the risk of having multi-symptom asthma.

Growing up on a farm leads to lifelong protection against allergic rhinitis

BACKGROUND

Various studies have reported a low prevalence of allergic rhinitis in farmers and farmers' children. We sought to investigate whether the protective effect of childhood farm environment is conserved throughout adulthood and how it corresponds to different degrees of urbanization.

METHODS

A questionnaire on respiratory health was mailed in 2008 to 30,000 randomly selected subjects aged 16-75 in West Sweden, 29,218 could be traced and 18,087 (62%) responded. The questionnaire included questions on allergic rhinitis, asthma, respiratory symptoms and possible determinants.

RESULTS

When stratified into age groups of 15 years, subjects that lived on a farm during their first 5 years of life had a lower prevalence of allergic rhinitis in all groups, even among the oldest (61-75 years). The negative correlation between childhood farm living and prevalence of allergic rhinitis was similar in 46-75 years of age (OR 0.82; 95% CI 0.70-0.95) as in 16-45 years of age (OR 0.78; 0.64-0.95). There was a significant trend of increasing prevalence of allergic rhinitis with increasing degree of urbanization independent of the effect of childhood farm living.

CONCLUSIONS

We found a lifelong protective effect of childhood farm living on the prevalence of allergic rhinitis. In addition, we found an increasing prevalence of allergic rhinitis with increasing degree of urbanization both in those raised on a farm and those not, thus emphasizing the influence of both childhood and adult exposure for the development of allergic disease.

Increase in asthma and a high prevalence of bronchitis: results from a population study among adults in urban and rural Vietnam

BACKGROUND

While a large amount of data about the epidemiology of asthma, COPD, chronic bronchitis and respiratory symptoms are available from developed countries, the information about these diseases in developing countries in south-east Asia are scarce.

AIM

Assess the prevalence of respiratory diseases and symptoms and their relation with demographic data including smoking habits among adults in rural and urban Vietnam.

METHODS

A random sample of subjects aged 21-70 years were invited; 3008 subjects living in an inner city area of Hanoi and 4000 in a rural area of Bavi in northern Vietnam. An internationally used questionnaire was delivered by field workers to the study subjects. The questionnaire was completed by the subjects, or when necessary, by the field workers after reading the questions for the study participants.

RESULTS

The response rate was 92% in Bavi and 70% in Hanoi. Of men in Bavi 67.8% (Hanoi 49.7%; p < 0.001) were smokers, while of women 4.2% were smokers in Hanoi (Bavi 1.2%; p < 0.001). The prevalence of ever asthma was in Hanoi 5.6% (Bavi 3.9%; p = 0.003) with no major gender difference. The most common symptom was longstanding cough (Hanoi 18.1%, Bavi 12.0%; p < 0.001) followed by sputum production, while the prevalence of symptoms common in asthma was considerably lower. Although the large difference in smoking habits, respiratory symptoms tended to be only slightly more common in men than women. Family history of asthma and chronic bronchitis, respectively, were strongly associated with both diseases.

CONCLUSIONS

The prevalence of asthma in adults may have increased in both urban and rural Vietnam, as the few previous estimates have found 2% of adults having asthma. Half of men in Hanoi and two-thirds in Bavi were smokers versus a few percent of women in both areas. Bronchitic symptoms were common in both men and women.

The prevalence of asthma and COPD in Italy: a practice-based study

We conducted a population-based cross-sectional epidemiologic survey of asthma and COPD in an adult representative national sample using information obtained from the Health Search Database owned by the Italian College of General Practitioners. General Practitioners who had a list of patient population of 909,638 individuals (429,962 men and 479,676 women; man/woman ratio [M/WR]: 0.89) ≥ 14 years old at the end of December 2009 were selected to be representatives of the whole Italian population. Cases of asthma and COPD were identified on the basis of the ICD-9 codes. The total sample included 55,500 (6.10% of the entire population; 5.49% of men and 6.64% of women; M/WR: 0.74) subjects suffering from asthma and 25,762 (2.83% of the entire population; 3.51% of men and 2.23% of women; M/WR: 1.41) subjects suffering from COPD. The asthma/COPD ratio in general population was 2.16. The odds ratio (OR) was chosen because asthma and COPD had a prevalence less than 10%. The OR of developing asthma decreased with age both in men and women, but in the first group of age (15-34 years) it was higher in men vs. women (1.69 vs. 1.00) although it became lower than 1 from 35 years old and up in men and from 75 years old and up in women. On the contrary, the OR of developing COPD became higher than 1 from 55 years old and up both in men and in women and progressively increased with age (in the group 75-84 years, it was 6.16 in men and 4.07 in women, respectively).

Incidence and prevalence of adult asthma is associated with low socio-economic status

BACKGROUND

Low socio-economic status is often related to health problems; however, previous studies on asthma, usually cross-sectional, yield inconsistent results. In this study, longitudinal and cross-sectional data on the association between socio-economic status and asthma as well as respiratory symptoms among adults are presented.

METHODS

A postal questionnaire was sent on two occasions, 1996 and 2006, to a randomly selected sample of subjects aged 20-69 years in 1996. In total, 4479 subjects participated in both surveys. The questionnaire included questions on asthma, respiratory symptoms and possible determinants. Logistic regression analysis, adjusted for potential confounders, was used to study the association between asthma, respiratory symptoms and socio-economic status.

RESULTS

Manual workers in service had the highest prevalence and cumulative incidence for all investigated symptoms and asthma. Despite a large decrease in smokers, the increase in incident bronchitic symptoms was higher than the increase of incident asthma and incident asthmatic symptoms. Low socio-economic status, rhinitis and a family history of asthma were risk factors for having and developing asthma and respiratory symptoms.

CONCLUSION

Low socio-economic status is significantly associated with an increased risk for prevalent and incident asthma and respiratory symptoms in this longitudinal population-based survey. The increase in risk was most pronounced in manual workers. Several studies have recently shown an association between low socio-economic status and respiratory symptoms and we conclude that asthma can not be considered as a disease that mainly affects the middle and upper socio-economic classes.

Swimming and asthma: factors underlying respiratory symptoms in competitive swimmers

BACKGROUND

Swimming is recommended for asthmatics. However, many competitive swimmers report asthmatic symptoms. While some studies identify the swimming environment as a trigger for allergy and asthmatic symptoms, even more studies suggest swimming to be suitable for people with allergies and asthma. The factors behind the symptoms were studied first by determining the prevalence of asthma, allergy and self-reported asthmatic symptoms in experienced Finnish swimmers and then by examining the relationships between the reported symptoms and the main triggering factors: medical history, environment and exercise intensity.

MATERIALS AND METHODS

Top swimmers (n = 332) of the Finnish Swimming Association registry (N = 4578) were asked to complete a structured questionnaire on their medical history, swimming background, swimming environment and symptoms in different swimming intensities. Two hundred experienced swimmers, 107 females and 93 males, with an average age of 18.5 [standard deviation (SD) = 3.0] years and a swimming training history of 9 (SD = 3.8) years completed the questionnaire.

RESULTS

Physician-diagnosed asthma was reported by 32 swimmers (16%), including 24 (12%) with exercise-induced asthma. Physician-diagnosed allergy was reported by 81 (41%) swimmers. Asthmatic symptoms during swimming were described by 84 subjects (42%). Most symptoms occurred when swimming exceeded speeds corresponding to the lactic/anaerobic threshold. Family history of asthma was significant and the most important risk factor for asthmatic symptoms.

CONCLUSIONS

The prevalence of asthma in swimmers was higher than in the general population but not different from that in other endurance athletes. Family history of asthma and increased swimming intensity had the strongest associations with the reported asthmatic symptoms.

Asthma in late adolescence--farm childhood is protective and the prevalence increase has levelled off

While the prevalence of and risk factors for asthma in childhood have been studied extensively, the data for late adolescence are more sparse. The aim of this study was to provide up-to-date information on the prevalence of and risk factors for asthma in the transitional period between childhood and adulthood. A secondary aim was to analyze whether the increase in asthma prevalence has levelled off. A large-scale, detailed postal questionnaire focusing on asthma and respiratory symptoms, as well as possible risk factors, was mailed to 30 000 randomly selected subjects aged 16-75 in Gothenburg and the surrounding western Sweden region. The present analyses are based on the responses from 1261 subjects aged 16-20 (560 men and 701 women). The prevalence of physician-diagnosed asthma was 9.5%, while 9.6% reported the use of asthma medicine. In the multivariate analysis, the strongest risk factors for physician-diagnosed asthma and other asthma variables were heredity for asthma and heredity for allergy, particularly if they occurred together. Growing up on a farm significantly reduced the prevalence of physician-diagnosed asthma and the likelihood of using asthma medication, OR 0.1 (95% CI 0.02-0.95). Smoking increased the risk of recurrent wheeze, long-standing cough, and sputum production. In conclusion, the prevalence of physician-diagnosed asthma and the use of asthma medication in the 16- to 20-yr age group support the notion that the increase in asthma prevalence seen between the 1950s and the 1990s has now levelled off. In line with the hygiene hypothesis, a farm childhood significantly reduced the likelihood of asthma. The adverse effects of smoking could already be seen at this young age.

FinEsS-Stockholm and the Stockholm adult asthma study

Two major studies on asthma and respiratory symptoms are presently in progress in Stockholm. The FinEsS-studies has been ongoing since 1996, with a follow-up study preformed in 2006 and a new cohort selected in 2007. The FinEsS studies focus on prevalence and incidence of asthma and respiratory symptoms in a general population. Clinical follow-up surveys will also target COPD. Further aims include remission and relapse of disease and symptoms and their determinants. The Stockholm adult Asthma Study (SaAS) began in the spring of 2007 and data is being collected presently. The SaAS study focus on the medical care and medication given to asthmatics in Stockholm, and the study population consists of asthmatics found in the two Swedish cohort studies.

General population-based cohorts for studies of lung health in adults in Sweden

Epidemiological population-based studies about lung health in Sweden have mostly been focused on obstructive airway diseases. From the 1960s to the 1980s, the epidemiological studies were cross-sectional, aiming at the study of the prevalence of asthma, chronic bronchitis and respiratory symptoms and their associations with mainly demographic data. With the exception of highly stratified samples, for instance the men born on 1913 in Gothenburg and cohorts of occupational groups or work places, general population-based cohorts for studies of lung health in adults are still not very common. Two large-scale studies of lung health have been in progress in Sweden for more than 20 years; the Obstructive Lung Disease in Northern Sweden (OLIN) Studies, which started in 1985, and the Swedish part of European Community Respiratory Health Survey (ECRHS) since 1989 with the follow-up survey labelled Respiratory Health in Northern Europe (RHINE). During the 1990s the comparative studies between Finland, Estonia and Sweden (The FinEsS Studies) started. These and other studies will be reviewed in the following exemplifying change of aims and study designs over time as well as change of focus of risk factors under study.

West Sweden Asthma Study: prevalence trends over the last 18 years argues no recent increase in asthma

Asthma prevalence has increased over the last fifty years, but the more recent changes have not been conclusively determined. Studies in children indicate that a plateau in the prevalence of asthma may have been reached, but this has not yet been confirmed in adults. Epidemiological studies have suggested that the prevalence of asthma in adults is approximately 7-10% in different parts of the western world. We have now performed a large-scale epidemiological evaluation of the prevalence of asthma and respiratory symptoms in adults between the ages of 16-75 in West Sweden. Thirty thousand randomly chosen individuals were sent a detailed questionnaire focusing on asthma and respiratory symptoms, as well possible risk factors. Sixty-two percent of the contacted individuals responded to the questionnaire. Asthma prevalence, defined as asthma diagnosed by a physician, was 8.3%. Moreover, the prevalence of respiratory symptoms was lower compared to previous studies. The most common respiratory symptom was any wheeze (16.6%) followed by sputum production (13.3%). In comparison with studies performed 18 years ago, the prevalence of asthma has not increased, and the prevalence of most respiratory symptoms has decreased. Therefore, our data argues that the continued increase in asthma prevalence that has been observed over the last half century is over.

LONG-TERM CLEARANCE FROM SMALL AIRWAYS IN PATIENTS WITH CHRONIC BRONCHITIS: EXPERIMENTAL AND THEORETICAL DATA

Long-term clearance (21 days) from small airways was studied in 9 patients with chronic bronchitis (CB), 65 +/- 10 (mean +/- SD) years, and was compared to 15 age-matched healthy subjects of 67 +/- 7 (mean +/- SD) years. Six of the CB patients were studied twice. All subjects inhaled monodisperse 6 microm Teflon particles labelled with 111In with an extremely slow inhalation flow, 0.05 L/s. With this inhalation technique, particles are deposited mainly in the small conducting airways. Lung retention was measured at 0 and 24 hours, and at 7, 14, and 21 days after inhalation. Lung retention at 24 hours (% of deposition) was highly reproducible for the CB patients, studied twice, but it was not significantly different from that found for healthy subjects and, furthermore, not related to airway resistance (Raw), nor FEV1% predicted. Both healthy subjects and CB patients showed significant clearance in the period between 24 hours and day 21. The mean retention were higher (P<.001) in CB patients, 90%, 89%, 87% of 24 hours retention at 7, 14, and 21 days, compared to 80%, 76%, 71% of 24 hours retention at 7, 14, and 21 days measurements for healthy subjects. Clearance after 24 hours (retention at 21 days) was significantly related to FEV1% predicted, but not Raw. Reduced FEV1% predicted values was associated with slower clearance rates. Model calculations were performed to estimate intrapulmonary deposition patterns. A limited effect was shown for airway dimension and uneven ventilation. The differences between healthy and CB patients were, however, limited. It is not possible to conclude whether the difference in clearance after 24 hours is an effect of change in regional deposition, or slower small airway clearance in diseased airways. This technique to target the smallest ciliated airways, using an extremely slow inhalation flow, provides new possibilities to investigate smallest airway function and drug delivery that merits further investigations.

Decline in FEV1in Relation to Incident Chronic Obstructive Pulmonary Disease in a Cohort with Respiratory Symptoms

Data on the relationship between decline in lung function and development of COPD are sparse. We assessed the decline in FEV1 during 10 years among subjects with respiratory symptoms by two different methods and evaluated risk factors for decline and its relation to incident Chronic Obstructive Pulmonary Disease, COPD. A cross-sectional postal questionnaire was in 1986 sent to 6610 subjects of three age strata. All subjects reporting respiratory symptoms were invited to a structured interview and spirometry. A follow-up survey was performed 10 years later, and totally 1109 subjects performed spirometry in both 1986 and 1996. COPD was defined according to the ATS/ERS standards (FEV1/FVC < or =0.70). The decline in FEV1 was 39 ml/year in men vs. 28 ml/year in women, p = < 0.001 (-1.53 vs. -0.12 change in percent of predicted normal value over 10 years (pp), p = 0.023), among smokers 39 vs. non-smokers 28 ml/year, p < 0.001 (-3.30 vs. 0.69 pp, p < 0.001), in subjects with chronic productive cough 36 vs. not 32 ml/year, p = 0.044 (-2.00 vs. -0.02 pp, p = 0.002). Incident cases of moderate COPD (n = 83) had a decline of 62 ml/year (-12.6 pp) and 22.9% of them had a decline > 90 ml/year (-27.8 pp over 10 years). Gender-specific analysis revealed that smoking was a stronger risk factor in women than in men, while higher age was a significant risk factor in men only. In conclusion, decline in FEV1 was associated with age, smoking, and chronic productive cough, but the risk factor pattern was gender-dependent. Among incident cases of COPD the decline was steeper and close to a quarter had a rapid decline.

Respiratory symptoms and lung function in foundry workers exposed to low molecular weight isocyanates

BACKGROUND

This study investigated the prevalence of ocular and respiratory symptoms and lung function in foundry workers exposed to isocyanic acid (ICA) and methyl isocyanate (MIC).

METHODS

Foundry workers (n = 64) using the Hot Box binder technique and referents (n = 134) completed two questionnaires and a spirometry before and after a day shift. Findings were analyzed relating to exposure measurements of ICA, MIC, and formaldehyde.

RESULTS

Exposed workers reported more frequently ocular irritation and coughing. Pre-shift lung function was lower than predicted in both groups of workers, and was not associated with exposure duration. Decrease in lung function over shift was more pronounced in exposed workers, but this was not associated with quantitative measures of the exposures.

CONCLUSIONS

An increased prevalence of ocular and respiratory symptoms, as well as a small decrease in lung function over shift, was observed among exposed workers. No associations with exposure to monoisocyanates and formaldehyde were seen, thus suggesting that other irritants in the foundry environment might be the cause. The effects seemed to be small and not clinically relevant on an individual level. Further studies using a follow-up design may be warranted.

Long-term health outcomes in pediatric inflammatory bowel disease: a population-based study

BACKGROUND

The long-term sequelae of inflammatory bowel disease (IBD) may differ between children and adults. We evaluated the health status of patients with pediatric onset of IBD and controls in early adulthood.

METHODS

A questionnaire on the current health status and disease history was mailed to patients with childhood onset IBD diagnosed during 1987-2003 in 2 university hospitals in Finland. Matched controls were randomly selected from the Population Register Centre.

RESULTS

A total of 368 (67%) of the 550 patients and 646 (37%) controls responded (median age 20 years). Ulcerative colitis (UC) was the most common primary diagnosis (58%) reclassified as Crohn's disease (CD) in 8.5%. Of the patients, 80% had been on glucocorticoids at some point (median duration of the disease 8.3 years). One-third of CD patients had undergone intestinal resection. In UC, total colectomy was common (24%). The frequency of joint diseases (5.4% versus 0.2%) and biliary duct diseases (2.7% versus 0.3%) was higher in patients than in controls (P < 0.001). Overall quality of life was decreased in the patients (mean score 5.7 versus 6.0 in controls, P < 0.001). Further, some impediment on adult height and weight was observed among male patients.

CONCLUSIONS

IBD in children may have a more aggressive disease course than in adults, since most pediatric patients need glucocorticoids, and abdominal surgery is frequent. At 8 years from diagnosis, most patients have active disease and quality of life is slightly lower than in the rest of the population.

No further increase of incidence of asthma: incidence, remission and relapse of adult asthma in Sweden

BACKGROUND

Knowledge about time trends of disease patterns in society is essential for planning and prioritizing health care resources. Longitudinal population-based studies on asthma are scarce but provide an opportunity to assess incidence, remission and relapse of asthma, and their determinants, which were the objectives of the present study.

METHODS

A postal questionnaire was sent on two occasions, 1996 and 2006, to a randomly selected sample of subjects aged 20-69 years in 1996. The response rates were 72% and 83%, respectively, and in total 4479 subjects participated in both surveys. The questionnaire included questions on asthma, respiratory symptoms and possible determinants. Logistic regression was used to assess determinants.

RESULTS

Cumulative incidence of asthma was 2.4% (men 1.9%; women 2.8%, p=0.06). Family histories of asthma (OR 2.31, CI 95% 1.42-3.76), rhinitis (OR 2.25, CI 95% 1.43-3.53) and being an ex-smoker (OR 2.17, CI 95% 1.27-3.71) were determinants for incident asthma. The 10-year remission of asthma was 14.6% and inversely associated with rhinitis. Relapse was found in 38% of eligible subjects.

CONCLUSIONS

The current study with high participation rates concludes that the incidence of asthma among adults has been stable in Sweden for the past two decades. Remission was associated with mild disease at study start. Relapse in adults has rarely been reported previously and provide new insight in the course of asthma. Low remission and high relapse further support the view of asthma as a chronic disease; possibly representing fluctuations of the disease over time.

Asthma mortality among Swedish children and young adults, a 10-year study

BACKGROUND

Previous reports indicate that morbidity and mortality from asthma have increased during the past decades. Here, the mortality rate associated with asthma and possible risk factors in children and young adults in Sweden during the period 1994-2003 were evaluated.

METHODS

The medical profession was asked to report suspected cases of death from asthma in individuals 1-34 years of age. All death certificates containing relevant ICD codes were reviewed. Medical records and autopsy reports were assessed and telephone interviews with next-of-kin performed.

RESULTS

During the 10-year period 37 deaths due to asthma were identified. The median age at the time of death was 27 years and 6 of the deceased were younger than 15. The overall incidence of death from asthma decreased from 1.54 deaths per million in 1994 to 0.53 per million in 2003. Common risk factors were under-treatment (23/37), poor adherence to prescribed treatment (17/37) and adverse psychosocial situation (19/37). An alarming finding was that 11 of the 37 deaths were probably caused by food allergy and for 8 subjects death was associated with exposure to pet dander. The death certificates were found to contain inaccuracies with 30% of those for whom asthma was reported as the underlying cause having died from other causes.

CONCLUSION

Asthma mortality in children and young adults in Sweden decreased between 1994 and 2003. Food allergy and inadequate treatment were the major risk factors for such a death. Recognition and special care of patients with asthma who have shown signs of non-compliance, denial or severe food allergy must be encouraged.

Dispensed volumes of anti-asthmatic drugs related to the prevalence of asthma and COPD in Sweden

PURPOSE

To explore the possibility of using dispensed volumes asthma/COPD drugs as a proxy for the combined prevalence of asthma plus COPD.

METHODS

The proportions of the Swedish population with inhalation drugs for asthma/COPD 2004 were obtained using three different databases. A pharmacy record database gave the volumes of dispensed drugs (defined daily doses, DDDs of R03A + R03B drugs) for each patient, 20 years and older. The X-plain database of Apoteket AB gave drug sales data for Sweden and Swedish population data were obtained from Swedish statistics.

RESULTS

The sales volumes of asthma/COPD drugs were much higher for older than for younger people. The volumes increased from 18 DDD/TID for the 20-29 year group up to 124 DDD/TID for patients 70-79 years, or about seven times. The average volumes per patient in the different age groups corresponded to one DDD/day in only three of the age groups (50-79 years). In the youngest group the average drug volume per patient corresponded to one DDD every second day, which may indicate undermedication. The percentages of the Swedish population with asthma/COPD drugs increased from 4.0% for 20-29 years old to 14.5% for 80+ years old, or 3.6 times. When head-to-head comparisons could be made between reported prevalence data of asthma and COPD and our data the two sets of data were in a reasonable agreement.

CONCLUSION

The prevalence of drug treatment, i.e. the proportion of the population with dispensed asthma/COPD drugs, could function as a proxy for the disease prevalence of asthma plus COPD.

Parental smoking behaviour and effects of tobacco smoke on children's health in Finland and Russia

BACKGROUND

There is little information on potential differences in smoking behaviour of parents between Finland and Russia and on the effects of environmental tobacco smoke (ETS) exposure on allergic and respiratory diseases among Finnish and Russian children. The aim of the study was to compare the smoking behaviour of parents and school children and to assess the relations of tobacco smoke exposure during pregnancy and childhood with occurrence of allergic diseases and respiratory infections among school children.

METHODS

We conducted a population-based cross-sectional study in the neighbour towns across the border of Imatra in Finland and Svetogorsk in Russia. The study population consisted of 512 Finnish and 581 Russian school children aged 7-16 years (response rate 79%).

RESULTS

Children's tobacco smoke exposure differed markedly between Finland and Russia. The risk of asthma was particularly related to high maternal smoking exposure during pregnancy (adjusted OR 3.51, 95% CI 1.00-12.3), infancy (3.34, 1.23-9.07) and currently (3.27, 1.26-8.48), and the risk of common cold was related to high combined parental smoking during infancy (1.83, 1.06-3.17) in Finnish children. Among Russian children allergic conjunctivitis was related to maternal smoking during infancy (4.53, 1.49-13.8) and currently (2.82, 1.07-7.44).

CONCLUSIONS

Smoking behaviour of parents and ETS exposure during childhood differed markedly between Finland and Russia. Asthma was particularly increased in relation to high exposure to maternal smoking in Finland. The results suggest that more efforts should be directed to reducing tobacco smoke exposure of children in both Finland and Russia. (250 words).

Allergy in marathon runners and effect of Lactobacillus GG supplementation on allergic inflammatory markers

OBJECTIVE

We studied the prevalence of asthma and allergy in non-elite marathon runners and investigated the effects of probiotic supplementation on allergic inflammatory markers.

METHODS

Asthma and allergies were surveyed by questionnaire, and blood eosinophils, serum eosinophil cationic protein (ECP), total IgE, and Phadiatop were measured in 141 Finnish marathon runners who took part in the Helsinki City Marathon. They were also randomized to receive either Lactobacillus GG (LGG) or placebo during the 3 months of the pollen season prior to the marathon.

RESULTS

Lifetime prevalence of physician-diagnosed asthma was 4.3% (six out of 139 athletes), of allergic rhinitis 17.3% (24/139), of food allergy 5.0% (7/139), and of atopic eczema 4.3% (6/139). Prevalence of atopy was 31% (35/112), and 21% (24/112) of the athletes were sensitized to birch pollen. Asthma or allergy medication was used by 20% (28/139) of the athletes. During pollen season, serum ECP increased significantly in all athletes, and total IgE and Phadiatop in atopics. The marathon induced a significant eosinopenia but had no effect on serum ECP or total IgE. No differences in changes were seen between groups receiving LGG or placebo.

CONCLUSION

Non-elite marathon runners have asthma and allergies similar to Finnish general population. LGG supplementation did not prevent the increase of allergic markers during the pollen season, or the eosinopenia induced by the marathon.

Chronic productive cough in school children: prevalence and associations with asthma and environmental tobacco smoke exposure

Background

The relationships between chronic productive cough (CPC), environmental tobacco smoke (ETS) exposure, and asthma are not clearly established in children. Therefore, we wished to determine the prevalence of CPC and examine the relationships between CPC, ETS exposure, and asthma in young teenagers.

Methods

We performed a cross sectional survey of 2397 Seattle middle school students, 11–15 years old, using written and video respiratory-symptom questionnaires. We defined CPC as – daily cough productive of phlegm for at least 3 months out of the year; current asthma as – yes to "Have you had wheezing or whistling in your chest in the past 12 months?" and yes in the past year to any of the four video wheezing/asthma video scenarios; and ETS exposure as exposed to tobacco smoke at least several hours each day. We used multilogistic regression to examine relationships between CPC, asthma, and ETS exposure and included in the model the potentially confounding variables race, gender, and allergic rhinitis.

Results

The prevalence of CPC was 7.2%. Forty-seven percent (82/173) of children with CPC met criteria for current asthma, while only 10% (214/2224) of those without CPC had current asthma. Current asthma had the strongest associated with CPC, odds ratio (OR) 6.4 [95% CI 4.5–9.0], and ETS was independently associated with both CPC, OR 2.7 [1.8–4.1] and asthma, OR 2.7 [1.5–4.7].

Conclusion

In a population of young teenagers, CPC was strongly associated with report of current asthma symptoms and also with ETS exposure. This suggests that asthma and ETS exposure may contribute to CPC in children. However, this study was not designed to determine whether asthma was the actual cause of CPC in this population of children.

Different labelling of obstructive airway diseases in Estonia, Finland, and Sweden

Large differences in prevalence of asthma have been reported between westernised countries and the former Eastern European countries, and still no consensus about the reasons for the differences exists. The aim of this study was to assess diagnostic labelling of obstructive airway diseases, comparing subjects with respiratory symptoms and the diagnoses obtained in Estonia, Finland, and Sweden. A postal questionnaire was sent to population-based random samples, and 44,483 (76%) answers were obtained from the 58,661 invited in 1996. Among men, current smoking was most common in Estonia, 60%, followed by Finland, 39%, and Sweden, 28%. In all three countries, 30% of women were current smokers. Most respiratory symptoms including wheezing were most common in Estonia, also among non-smokers. The prevalence of asthma was 2.0% and chronic bronchitis 10.7% in Estonia, while the opposite was found in Sweden with an asthma prevalence of 7.8% and a chronic bronchitis prevalence of 3.1%. The pattern in Finland was similar to that of Sweden. The same differences between the three countries were found also among young subjects. The total proportion of diagnosed obstructive lung diseases in subjects with respiratory symptoms was similar, but the diagnosis of asthma was considerably more common in Finland and Sweden. Chronic bronchitis was favoured in Estonia, also among young adults irrespectively of what symptoms were present. In a multivariate model with correction for confounders, the risk (OR) for having a diagnosis of asthma was 5.65 (95% CI: 4.86-6.56) when living in Sweden, and 3.51 (95% CI: 3.00-4.12) in Finland, whereas risk for chronic bronchitis was 0.28 (0.25-0.31) and 0.22 (0.19-0.25), respectively, compared to Estonia. The study indicates differences in diagnostic practices of obstructive lung diseases between the three countries.

Prevalence of Bronchial Hyperresponsiveness and Asthma in the Adult Population in Thailand

OBJECTIVES

We conducted a nationwide cross-sectional survey of respiratory health in adults aged 20 to 44 years during 2001 to 2002 to determine the prevalence of bronchial hyperresponsiveness (BHR) and asthma in the adult Thai population.

DESIGN

Subjects were selected by a multistage stratified random sampling. The stratification was done on geographic area, age group, and sex. Subjects were interviewed with questionnaires and underwent spirometric testing. Methacholine challenge tests were performed on all subjects without contraindication to determine BHR defined as the provocative concentration of methacholine producing a 20% fall in FEV(1) < or = 8 mg/mL. Definite asthma was defined as BHR present with any asthma symptom within the past 12 months or demonstrated reversible airflow obstruction. Current diagnosed asthma was defined as previous physician-diagnosed asthma and any asthma symptom within the past 12 months or currently receiving asthma medication.

RESULTS

The study population was from 20 provinces of five geographic regions of Thailand and included 1,882 women and 1,572 men. The prevalence of BHR was 3.31% (95% confidence interval [CI], 2.68 to 3.94). However, if subjects with positive reversibility test results were included, the prevalence increased to 3.98% (95% CI, 3.30 to 4.67). The prevalence of definite asthma was 2.91% (95% CI, 2.32 to 3.50), whereas the prevalence of current diagnosed asthma by the questionnaire interview was 2.15% (95% CI, 1.66 to 2.63). The kappa index of the agreement between both definitions of asthma was 0.40, indicating poor to fair agreement.

CONCLUSION

The prevalence of BHR and asthma in the adult Thai population is relatively low as compared with western countries.

Prevalence of asthma, allergic rhinoconjunctivitis and allergic sensitization in Mongolia

BACKGROUND

Studies in countries, such as Mongolia, which are in transition from farming to industrial society permit evaluation of the impact of environmental change on atopic diseases.

METHODS

In the screening study, questionnaire data were obtained from 9453 subjects aged 10-60 years. In the clinical study, a subsample of 869 subjects (participation rate 50.0%) was examined. A questionnaire-based interview, clinical examination, skin prick tests, spirometry and bronchodilation test or methacholine challenge test were used to define the clinical diagnoses. The prevalences of atopic diseases were evaluated at the population level using two-phase data and sampling weights.

RESULTS

The prevalences of asthma, allergic rhinoconjunctivitis and allergic sensitization with 95% confidence intervals were 1.1% (0.3-2.0%), 9.3% (4.0-14.6%) and 13.6% (7.4-19.9%) in Mongolian villages, 2.4% (1.4-3.5%), 12.9% (8.2-17.7%) and 25.3% (17.1-33.6%) in rural towns and 2.1% (1.3-3.0%), 18.4% (13.3-23.4%) and 31.0% (24.5-37.5%) in Ulaanbaatar city, respectively. The prevalence of allergic rhinoconjunctivitis (P = 0.02) and allergic sensitization (P = 0.003) increased significantly with increasing urbanization.

CONCLUSIONS

The prevalences of atopic diseases were low in rural Mongolia and increased with increasing urbanization suggesting that rural living environment protects against atopy.