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 (FENO) 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 FENO, 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 FENO.

Parallel gradients in FENO and in the prevalences of asthma and atopy in adult general populations of Sweden, Finland and Estonia - A Nordic EpiLung study.

The prevalence of asthma is higher in Sweden and Finland than in neighbouring eastern countries including Estonia. Corresponding difference in bronchial eosinophilic inflammation could be studied by FENO measurements. We aimed to compare FENO in adult general populations of Sweden, Finland, and Estonia, to test the plausibility of the west-east disparity hypothesis of allergic diseases. We conducted clinical interviews (N = 2658) with participants randomly selected from the general populations in Sweden (Stockholm and Örebro), Finland (Helsinki), and Estonia (Narva and Saaremaa), and performed FENO (n = 1498) and skin prick tests (SPT) in 1997-2003. The median (interquartile range) of FENO (ppb) was 15.5 (9.3) in Sweden, 15.4 (13.6) in Finland and 12.5 (9.6) in Estonia. We found the lowest median FENO values in the Estonian centres Saaremaa 13.1 (9.5) and Narva 11.8 (8.6). In the pooled population, asthma was associated with FENO ≥25 ppb, odds ratio (OR) 3.91 (95% confidence intervals: 2.29-6.32) after adjusting for SPT result, smoking, gender and study centre. A positive SPT test increased the likelihood of asthma OR 3.19 (2.02-5.11). Compared to Saaremaa, the likelihood of having asthma was higher in Helsinki OR 2.40 (1.04-6.02), Narva OR 2.45 (1.05-6.19), Örebro OR 3.38 (1.59-8.09), and Stockholm OR 5.54 (2.18-14.79). There was a higher prevalence of asthma and allergic airway inflammation in adult general populations of Sweden and Finland compared to those of Estonia. Atopy and elevated FENO level were independently associated with an increased risk of asthma. In conclusion, the findings support the earlier west-east disparity hypothesis of allergic diseases.

High prevalence of rhinitis symptoms without allergic sensitization in Estonia and Finland.

OBJECTIVES: Allergic rhinitis and atopy are more common in urban than rural environments. Non-allergic rhinitis has not been studied to a great extent. We aimed to assess the relationship of rhinitis symptoms with different profiles of allergic sensitization, comparing this in rural and urban environments. METHODS: The study population consisted of population-based cohorts of adults aged 26-60 from Helsinki, Finland, and rural Saaremaa and urban Tallinn, Estonia. We compared the results of a structured interview and skin prick tests and assessed the risk factors for rhinitis. RESULTS: The prevalence of rhinitis symptoms with atopy was 32.7% in Helsinki, 20.8% in Tallinn, and 12.5% in Saaremaa (p<0.001). Rhinitis symptoms without atopy were found in 26.4%, 29.8%, and 29.3% (p=n.s.), respectively. In Helsinki, 87.3% of participants with atopy identified symptoms as allergic, compared to 57.0% in Tallinn and 47.5% in Saaremaa. Childhood in the countryside (OR 0.63), family history of allergic rhinitis (OR 1.89), and polysensitization (OR 15.99) were significantly associated with rhinitis symptoms with atopy in a multivariate logistic regression model. The most common sensitizers were pollens and animals in Helsinki and mites in Estonia. Exposure to environmental tobacco smoke (OR 1.50) and family history of allergic rhinitis (OR 1.70) were associated with rhinitis symptoms without atopy. CONCLUSION: Rhinitis symptoms without allergic sensitization were common in both Finland and Estonia and were associated with environmental tobacco smoke. Family history of allergic rhinitis predisposed to rhinitis symptoms irrespective of atopy status.

Allergic sensitization to common airborne allergens among adults in Estonia.

BACKGROUND: Allergies and asthma exhibit a growing health problem in the world. Sparse data are available about the prevalence of allergic sensitization in Estonia and Eastern Europe as well. We studied the prevalence of allergic sensitization, the associations between respiratory symptoms and allergic sensitization, and the influence of age, gender, area of residence, number of siblings and other demographic attributes on allergic sensitization in the population aged 17-69 years. METHODS: We conducted a cross-sectional study with 1,346 randomly selected participants distributed in 3 geographically and culturally distinct areas of Estonia. Sensitization to 15 aeroallergens was assessed by skin prick tests. The study also included a structured interview. RESULTS: The total prevalence of allergic sensitization was 33.0%. When estimated in patients aged 20-44 years, the prevalence was 38.5%. The most common sensitizer was cockroach followed by storage mites, while sensitization to cat, dog or pollen (common sensitizers in Scandinavian countries) was low. Allergic sensitization was significantly more common in urban and suburban compared with rural areas. Storage mites were the most common sensitizers in rural areas. Living in urban or suburban areas before the age of 5 significantly increased the risk for positive skin prick tests to several allergens. CONCLUSIONS: A higher prevalence of allergic sensitization than previously believed was found. Cockroach and storage mite allergens are suggested to be included in the routine investigation panel in Estonia.

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.

Low prevalence of asthma in westernizing countries-myth or reality? Prevalence of asthma in Estonia--a report from the "FinEsS" study.

AIM: The aim of this study was to examine the prevalence of asthma among adults in Estonia by using different diagnostic methods and criteria for the disease. METHODS: In 1995-1996, a postal questionnaire was randomly distributed in three areas of Estonia to a representative sample of 22,579 subjects aged 15-64 years. The participation rate was 78%. A clinical follow-up study including structured interview, skin prick test, lung function, and methacholine test, was performed from 1997 to 2000 among randomly selected responders to the postal questionnaire. Of 2676 subjects, 53% participated. RESULTS: The prevalence of physician-diagnosed asthma for the postal questionnaire (PQ) was 2.7%, and in the same subjects for the structured interview (SI) 3.8%. Respiratory symptoms, except recurrent wheeze, were more common in the SI than PQ. Combinations of symptoms, except wheezing with breathlessness apart from cold, were more prevalent in the PQ responders. The prevalence of asthma defined by different symptom combinations varied from 5.4% to 8.2%. Among responders, 71-87% demonstrated bronchial hyperreactivity defined as methacholine reactivity=8 mg/mL. The symptom combinations used as surrogate variables for asthma were strongly associated with a positive skin test. CONCLUSION: The low prevalence of physician-diagnosed asthma probably reflects a considerable underdiagnosis of asthma in Estonia. Disease criteria for asthma based on symptom combinations together with hyperreactivity yielded a prevalence of 5%-8%, which is similar to the prevalence of asthma among adults in neighboring Western countries.

Correct use of three powder inhalers: comparison between Diskus, Turbuhaler, and Easyhaler.

A Phase IV, 4-week, open, randomized multicenter parallel group trial compared correct use and acceptability of Diskus, Turbuhaler, and Easyhaler powder inhalers among 326 inhaler naive asthmatics/symptomatics. The subjects were asked to read the instruction leaflet before taking one dose at the first visit. The correct use was evaluated when the subject took the dose. After that, the subjects were instructed in correct use. The use of the devices was also videotaped at every visit, and independent referees judged correct use. Acceptability was evaluated by a questionnaire. At the first visit, the proportions of subjects who used the devices correctly were as follows: Easyhaler, 45%; Diskus, 43%; and Turbuhaler, 51%. The corresponding figures at the last visit were 84%, 89%, and 81%. The differences at any visit were not statistically significant. Acceptability was greater for Easyhaler and Diskus for three of eight items throughout the study, all pertaining to receiving the powder from the device and control of the inhalation of the powder. Patient education in the use of devices is important, because only half of the subjects used the devices correctly, and still after 4 weeks 10-20% could not use the devices satisfactorily, regardless of which device.

Postal survey on asthma, chronic bronchitis and respiratory symptoms among adult Estonians and non-Estonians (FinEsS-study).

BACKGROUND: According to the data of the population census held in Estonia in 1989, the resident population consisted of 61.5% Estonians and 38.5% non-Estonians, the majority of them being Russians--30.3%. The aim of this study was to investigate the prevalence of asthma, chronic bronchitis and respiratory symptoms among the adults in these ethnic groups. METHODS: The study was a postal survey, similar in design to parallel studies currently in progress in Finland, Estonia and Sweden (FinEsS). RESULTS: The prevalence of physician-diagnosed asthma was 2.0%, being similar in men and women and in both Estonians and non-Estonians. The prevalence of physician-diagnosed chronic bronchitis was 10.5%. Compared with the non-Estonian population, the prevalence was much lower among Estonians (7.9% vs. 13.5%, p<0.001). Such a difference in prevalence was observed in all age groups. The high prevalence of chronic bronchitis in non-Estonians could be related to more extensive smoking habits, smoking indoors and probably ETS exposure. The defined OR between non-Estonians vs. Estonians after correcting for the influence of smoking habits, area of domicile, age, gender, and socioeconomic group was 1.30. A similar pattern of differences between Estonians and non-Estonians was observed in respiratory symptoms. CONCLUSION: This study revealed that the prevalence of physician-diagnosed asthma in Estonians and non-Estonians was the same. Physician-diagnosed chronic bronchitis was more frequent in non-Estonians than in Estonians. A significant difference was determined in the prevalence of respiratory symptoms, especially among those common to chronic bronchitis. The differences remained significant after correction for possible confounders.