Allergic multimorbidity is associated with self-reported anaphylaxis in adults-A cross-sectional questionnaire study.

Background: Anaphylaxis has increased over the last two decades in Europe, reaching an estimated prevalence of 0.3% and an incidence of 1.5-7.9 per 100,000 person-years. Allergic multimorbidity is associated with asthma severity, yet its role in anaphylaxis is not fully understood. Our aim was to study association between allergic multimorbidity and anaphylaxis in adults. Methods: We used population-based data from the Finnish Allergy Barometer Study (n = 2070, age range: 5-75). Food allergy (FA), atopic dermatitis (AD), allergic rhinitis (AR) and allergic conjunctivitis (AC), were defined from a self-completed questionnaire. A logistic regression adjusted on potential confounders (sex, age, smoking status) was applied to estimate the anaphylaxis risk associated with allergic multimorbidity. Results: 1319 adults with at least one allergic disease (FA, AD, AR, AC) with/without asthma (AS) were included. Of these, 164 had self-reported anaphylaxis [mean (SD, min-max) 54 (14, 22-75) years, 17% men]. AS, FA, AR, AC, or AD were reported by 86.0%, 62.2%, 82.3%, 43.3%, and 53.7% of subjects with anaphylaxis and respectively by 67.8%, 29.5%, 86.2%, 29.4%, and 34.4% of subjects without anaphylaxis. Compared with subjects exhibiting only one allergic disease, the risk of anaphylaxis increased with the number of allergic diseases; adjusted odds ratios (OR) [CI95%] for two, three, four and five coinciding allergic diseases were 1.80 [0.79-4.12], 3.35 [1.47-7.66], 7.50 [3.25-17.32], and 13.5 [5.12-33.09], respectively. The highest risk of anaphylaxis (6.47 [4.33-9.92]) was associated with FA + AS or their various variations with AR/AC/AD embodied, when compared with AR, AC, and AS separately or their combinations. Conclusions: Anaphylaxis was positively associated with the number of allergic diseases a subject exhibited and with subgroups including FA and/or AS. The results can be applied when estimating the risk of anaphylaxis for individual patients.

The combined effect of exposures to vapours, gases, dusts, fumes and tobacco smoke on current asthma.

Smoking, exposure to environmental tobacco smoke (ETS) and occupational exposure to vapours, gases, dusts or fumes (VGDF) increase asthma symptoms. The impact of combined exposure is less well established. We aimed to evaluate the risk of combined exposure to smoking, ETS and VGDF on the prevalence of current asthma and asthma-related symptoms with a postal survey among a random population of 16,000 adults, aged 20-69 years (response rate 51.5%). The 836 responders with physician-diagnosed asthma were included in the analysis. Of them, 81.9% had current asthma defined as physician-diagnosed asthma with current asthma medication use or reported symptoms. There was a consistently increasing trend in the prevalence of current asthma by increased exposure. The highest prevalence of multiple symptoms was in smokers with VGDF exposure (92.1%) compared to the unexposed (73.9%, p = 0.001). In logistic regression analysis, combined exposure to several exposures increased the risk in all analysed symptoms (p = 0.002-0.007). In conclusion, smoking and exposure to ETS or VGDF increased the prevalence of current asthma and multiple symptoms. The combined exposure carried the highest risk. Preventive strategies are called for to mitigate exposure to tobacco smoke and VGDF.

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.

Does lung function predict the risk of disability pension? An 11-year register-based follow-up study.

BACKGROUND: Spirometry is widely used in medical surveillance in occupational health and as a diagnostic test for obstructive and restrictive lung disease. We evaluated the effect of spirometry parameters on the risk of all-cause disability pension in a follow-up study of an occupationally active general population-based cohort. METHODS: We measured the pulmonary function of 3386 currently working participants of the Health 2000 Survey in the clinical phase at baseline using spirometry. We obtained the retirement events of the cohort from the nationwide register for 2000-2011. Cox proportional hazards models were used to determine disability pensions. RESULTS: At baseline, we identified 111 (3.3%) participants with obstructive spirometry, 95 (2.8%) with restrictive spirometry, and 3180 controls without restriction or obstruction. The age, sex, educational level, body-mass index, co-morbidities (1 or ≥ 2), and the smoking-adjusted hazard ratio of disability pension was 1.07 (95% confidence interval, CI 0.64-1.78) for those with obstructive spirometry, and 1.44 (95% CI 0.89-2.32) for those with restrictive spirometry. As continuous variables, and divided into quartiles, the risk of the lowest quartile of forced ventilation capacity (FVC)% of predicted was 1.49 (95%CI 1.10-2.01) and forced expiratory volume in one second (FEV1)% of predicted 1.66 (95%CI: 1.23-2.24) in comparison to the highest quartile in the adjusted models. CONCLUSIONS: Obstructive or restrictive spirometry did not predict disability pension when dichotomized classified variables (normal compared to abnormal) were used. As continuous variables and when divided into quartiles, lower lung volumes showed an increase in the risk of disability pension. Physicians should take this into account when they use spirometry as a prognostic factor of work disability.

The increase of asthma prevalence has levelled off and symptoms decreased in adults during 20 years from 1996 to 2016 in Helsinki, Finland.

BACKGROUND: Mortality and hospitalization due to asthma have decreased in many European countries, but asthma symptoms still cause a lot of morbidity and costs. OBJECTIVES: We evaluated prevalence trends of asthma, asthma symptoms and allergic rhinoconjunctivitis in adults aged 20-69 years during a 20-year period from 1996 to 2016 in the city of Helsinki, the capital of Finland. METHODS: Three cross-sectional postal surveys were conducted in random population samples 10 years apart. In 1996, 2006 and 2016, a total of 6062 (response rate 75.9%), 2449 (61.9%) and 4026 subjects (50.3%) took part, respectively. RESULTS: In all responders, the prevalence of physician-diagnosed asthma was 6.6% in 1996, 10% in 2006 and 10.9% in 2016. The prevalence increased from 1996 to 2006, but stabilized from 2006 to 2016, both in men and women and in smokers and non-smokers. The prevalence of current asthma (8.5% in 2006 and 8.8% in 2016) and of asthma with rhinoconjunctivitis (7.6% in 2006 and 7.5% in 2016) remained also at the same level. Allergic rhinoconjunctivitis decreased significantly from 2006 (42.7%) to 2016 (39.0%, p = 0.004). Those with physician diagnosed asthma reported significantly less symptoms in 2016 compared to 2006 and 1996, although there was no change in smoking habits or medication use. Young asthmatics (20-29 years) without rhinoconjunctivitis reported least symptoms. CONCLUSION: Previously observed increase of physician-diagnosed asthma prevalence in adults seems to be levelling off in Helsinki, and patients have fewer symptoms than 20 years ago. In addition, allergic rhinoconjunctivitis is less frequent than 10 years earlier. (247 words).

Smoking, environmental tobacco smoke and occupational irritants increase the risk of chronic rhinitis.

BACKGROUND: Allergic and non-allergic rhinitis cause a lot of symptoms in everyday life. To decrease the burden more information of the preventable risk factors is needed. We assessed prevalence and risk factors for chronic nasal symptoms, exploring the effects of smoking, environmental tobacco smoke, exposure to occupational irritants, and their combinations. METHODS: In 2016, a postal survey was conducted among a random population sample of 8000 adults in Helsinki, Finland with a 50.5% response rate. RESULTS: Smoking was associated with a significant increase in occurrence of chronic rhinitis (longstanding nasal congestion or runny nose), but not with self-reported or physician diagnosed allergic rhinitis. The highest prevalence estimates of nasal symptoms, 55.1% for chronic rhinitis, 49.1% for nasal congestion, and 40.7% for runny nose, were found among smokers with occupational exposure to gases, fumes or dusts.Besides active smoking, also exposure to environmental tobacco smoke combined with occupational exposure increased the risk of nasal symptoms. CONCLUSIONS: Smoking, environmental tobacco smoke, and occupational irritants are significant risk factors for nasal symptoms with an additive pattern. The findings suggest that these factors should be systematically inquired in patients with nasal symptoms for appropriate preventive measures. (192 words).

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.

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.

Combined effect of smoking and occupational exposure to dusts, gases or fumes on the incidence of COPD.

To assess risk factors related to the development of chronic obstructive pulmonary disease (COPD) including smoking and occupational exposure (OE) to dusts, gases or fumes, we performed a longitudinal 11-year follow-up postal survey. The original study population was a random population sample of 8000 inhabitants of Helsinki aged 20 to 69 years in 1996. Participants of the first postal questionnaire were invited to this follow-up survey in 2007 with 4302 (78%) answers obtained. Cumulative incidence of COPD in 11 years was 3.43% corresponding to an incidence rate of 3.17/1000/year after exclusion of those with self-reported physician-diagnosed COPD and ever COPD in 1996. Smoking and age, but not gender, were associated with incident COPD. Reported family history of COPD increased the cumulative incidence to 8.55% vs 3.04% among those without a family history (p < 0.001). In multivariate analysis, significant independent risk factors for incident COPD were: current smoking in 1996 (OR 4.40 [95% CI 2.89-6.71]), age over 50 (OR 3.42 [95% CI 2.22-5.26]), family history of COPD (OR 2.08 [1.27-3.43]), ever asthma (OR 2.28 [1.35-3.86]), and self-reported OE (OR 2.14 [1.50-3.05]). Occupational exposure to dusts, gases or fumes, assessed both based on self-reported exposure and a job exposure matrix using reported professions, was an independent risk factor for incident COPD. Smoking and OE together yielded an additive effect on incidence of COPD.

Dose-dependent association of smoking and bronchial hyperresponsiveness.

Our aim was to study the association of smoking habits and environmental tobacco smoke (ETS) exposure with bronchial hyperresponsiveness (BHR). A random sample of 292 adults was examined using a structured interview, spirometry, skin prick tests, exhaled nitric oxide fraction (FeNO) and bronchial histamine challenge. A large majority of subjects with BHR were smokers or ex-smokers. Starting to smoke before 20 years of age was significantly associated with BHR, as was current smoking, quantity of smoking and ETS exposure. The severity of BHR increased significantly with increasing pack-years of exposure (p<0.001). Current smokers with decreased lung function were at a particularly high risk of BHR. Impaired forced expiratory volume in 1 s and mean maximal expiratory flow were independent determinants for more severe BHR, regardless of age. In multivariate analysis, smoking remained an independent determinant for BHR after adjustment for impaired lung function and other covariates: ≥15 pack-years yielded an odds ratio of 3.00 (95% CI 1.33-6.76) for BHR. The association between BHR and FeNO was dependent on smoking habits. The results indicate that smoking is a significant risk factor for BHR, with a dose-dependent pattern, and that the severity of BHR increases with pack-years. The findings strongly suggest assessment of smoking habits in subjects with BHR.

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.

Lung function predicts mortality: 10-year follow-up after lung cancer screening among asbestos-exposed workers.

PURPOSE: To assess the predictive value of lung function impairment on mortality among asbestos-exposed workers. METHODS: A total of 590 workers originally screened for occupational lung disease including spirometry and pulmonary diffusing capacity measurements were followed up for mortality data (ICD-10 classification). The mean follow-up time was 10.5 years. Associations of different lung function parameters with mortality from all causes and from cardiovascular (I00-I99) and non-malignant respiratory diseases (J00-J99) were analysed. Factor analysis was used to create obstructive and restrictive factors. RESULTS: A total of 191 deaths were found altogether. Most measured lung function variables were associated with increased mortality when studied separately. Both decreased forced expiratory flow in one second (hazard ratio/measurement unit = 0.977, 95 % CI 0.969-0.988, p < 0.001) and impaired diffusing capacity (0.973, 0.965-0.981, p < 0.001) were independently associated with mortality from all causes, as well as from cardiovascular and non-malignant respiratory diseases. Both obstructive factor alone and the sum of obstructive and restrictive factors were associated with all studied mortality categories. The restrictive factor alone was associated with all-cause and respiratory mortality. CONCLUSIONS: Deteriorated lung function predicts deaths. The reasons for impaired lung function should be medically explored to enable restoring measures aiming thus to prevent premature deaths.

Positive exercise test and obstructive spirometry in young male conscripts associated with persistent asthma 20 years later.

BACKGROUND: Asthma often begins in childhood or early adulthood and is a common disease among conscripts. The identification of long-term predictive factors for persistent asthma may lead to improved treatment opportunities and better disease control. OBJECTIVE: Our aim was to study the prognostic factors of the severity of asthma among 40-year-old male conscripts whose asthma began in youth. METHODS: We studied 119 conscripts who were referred to the Central Military Hospital during 1987-1990 due to asthma and who attended a follow-up visit approximately 20 years later. Asthma severity was evaluated during military service according to the medical records, and 20 years later during a follow-up visit using Global Initiative for Asthma guidelines. We used the results of lung function and allergy tests at baseline as predictors of current persistent asthma. RESULTS: Compared with baseline, asthma was less severe at follow-up: 11.8% of subjects were in remission, 42.0% had intermittent asthma, 10.9% had mild persistent asthma, and 35.3% had moderate/severe persistent asthma (p < .001). In multivariate models, a positive exercise test at baseline yielded an odds ratio (OR) of 3.2 (95% CI 1.0-9.8, p = .046), a decreased FEV1/FVC % predicted an OR of 4.0 (95% CI 1.7-9.3, p = .002), and a decreased FEF50% % predicted an OR of 2.8 (95% CI 1.3-6.4, p = .012) for current persistent asthma. CONCLUSIONS: About half of the men had persistent asthma at the 20-year follow-up. Positive exercise tests and obstructive spirometry results were related to the persistence of asthma and may be useful long-term prognostic factors for asthma severity.

[Peak expiratory flow monitoring--the basis for diagnosing occupational asthma--guidelines by the Finnish Expert Group on Occupational Lung Diseases]. / Ammattikeuhkosairauksien asiantuntijaryhmän (AKAR) suositus. PEF-työpaikkaseuranta--ammattiastma-diagnostiikan perusta.

Occupational exposures can cause adult-onset asthma. Early diagnosis and early avoidance of further exposure to causative agent improves the prognosis of occupational asthma. Occupational and primary care health services have an important role in the identification of new cases of occupational asthma. For the diagnosis of occupational asthma, serial peak expiratory flow (PEF) measurements should be performed in an early stage. Although it requires an effort from the patient, high quality recordings offer the best approach to assess the relationship between workplace exposure and respiratory symptoms. Good guidance and performance of serial PEF measurements in primary care is recommended and is worth the effort.

[Specific challenge tests in occupational asthma--guidelines by the Finnish Expert Group on Occupational Lung Diseases]. / Ammattikeuhkosairauksien asiantuntijaryhmän (AKAR) suositus. Hengitysteiden spesifiset altistuskokeet ammattiastman osoittamisessa.

In a specific inhalation challenge (SIC) test the patient inhales an occupational agent in controlled environment and the subsequent asthmatic reaction is monitored. SIC is considered as the reference standard when confirming the diagnosis of sensitizer-induced occupational asthma. However, SIC is not always needed for the diagnosis; in many cases the causal relationship between an occupational agent and asthma can be shown also with serial peak flow measurements and specific immunologic testing. SIC is invaluable in identifying new occupational airway sensitizers. This is essential for preventing occupational asthma in the future.

Reduced work ability in middle-aged men with asthma from youth--a 20-year follow-up.

We studied, whether asthma diagnosed in childhood or early adulthood affects work ability 20 years later. We used Finnish Defence Force registers, 1986-1990, to select: (1) conscripts with asthma to represent a mild/moderate asthma group (n=485), (2) asthmatics who were exempted from military service to represent a relatively severe asthma group (n=393) and (3) a control group (n 1500) without asthma. A questionnaire consisting of validated questions on asthma and work ability was sent out in 2009. A total of 54% of the men in the first study group, 44% of those in the second study group and 44% of the controls answered. The mean age of the participants was 41 (range 37-51). Self-assessed current work ability compared with lifetime best had decreased in 28.9% of the first asthma group, in 31.1% of the second asthma group, and in 19.7% of the controls (p = 0.0007). Current smoking (OR 2.5), only basic education (OR 2.6), being a manual worker (OR 2.7) and current severe asthma (OR 3.8) associated most strongly with decreased work ability among the asthmatics. Both mild and more severe asthma at the age of around 20 seems to be associated with reduced work ability in 40-year-old males.

Equally elevated concentrations of exhaled nitric oxide in nonatopic and low-sensitized atopic asthmatics.

BACKGROUND: Some studies show concentrations of exhaled nitric oxide (FENO) in nonatopic asthma and in healthy subjects to be similar, but include asthmatics on inhaled steroids, which is likely to interfere with the results. AIM: Comparison of FENO between nonatopic asthmatics, low-sensitized and high-sensitized atopic asthmatics, and healthy controls. METHODS: We studied 85 non-smoking, steroid-naive young men with recently diagnosed symptomatic asthma and 10 healthy controls. FENO was measured according to European Respiratory Society Guidelines. In skin prick tests of 13 common aeroallergens, subjects with a total sum of prick wheals 3-10mm were regarded as low-sensitized and those with >10mm, as high-sensitized. Flow-volume spirometry, standardized histamine challenge, and an exercise test were also carried out. RESULTS: Prick tests revealed 14 subjects to be nonatopic and 71 atopic. In high-sensitized subjects with atopic asthma, the FENO median (25-75 quartiles) was significantly higher, 34.9 (21.3-53.8) parts per billion (ppb), than in subjects with nonatopic asthma, 15.2 (9.7-24.7)ppb (p<0.001), both being significantly higher than in healthy controls, 6.6 (5.2-8.5)ppb (p<0.001). FENO levels were similar in nonatopic and in low-sensitized atopic asthmatics, with no difference between them in bronchial responsiveness to histamine and exercise. CONCLUSION: Among steroid-naive young male asthmatics, FENO was equally elevated in nonatopic asthma and in low-sensitized atopic asthma but lower than in those with high-sensitized atopic asthma. These differences in FENO between asthma groups parallel the differences in airway function disturbance in terms of responsiveness to histamine or exercise.

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.

Respiratory symptoms and asthma in relation to cold climate, inhaled allergens, and irritants: a comparison between northern and southern Finland.

We have compared data from northern and southern Finland in a large epidemiological survey on respiratory conditions. The aim was to compare the prevalence of respiratory symptoms, asthma, and chronic bronchitis in northern and southern Finland. The study was a part of comparative studies in Finland, Estonia, and Sweden, the FinEsS studies. Data from a postal survey on subjects aged 20-69 was analyzed. Participation rate was 84% of 7937 invited in Lapland in the north, and 77% of 7877 in Helsinki in the south. Physician-diagnosed asthma was reported by 5.6% in Helsinki, and by 5.5% in Lapland. Symptoms common in asthma were also equally prevalent in the two areas. Hay fever was significantly more common in Helsinki, 36% vs. 26% (p < 0.001). The prevalence for physician-diagnosed chronic bronchitis was not significantly higher in Helsinki (3.4%) than in Lapland (2.9%). Those working outdoors reported more bronchitic symptoms than people working indoors (p < 0.05). Respiratory symptoms provoked by pollen or animal dander were more common in Helsinki, while symptoms provoked by inhaled irritants or cold weather conditions were more prevalent in Lapland. Current smoking was equally prevalent: 37% in Lapland and 38% in Helsinki. Risk factor analysis showed an elevated risk for chronic productive cough for living in Helsinki (OR 1.32), however, increasing age and current smoking were the strongest risk factors. In conclusion, prevalence of asthma and asthma-related symptoms was similar in southern and northern Finland, but chronic bronchitis and bronchitic symptoms were more common in Helsinki, and the highest prevalence was found among current smokers working outdoors. Respiratory symptoms in cold weather were more prevalent in the north, while hay fever and respiratory symptoms provoked by allergens were more common in the south. The results support the view that environmental factors have a substantial effect on respiratory symptoms, but less effect on the prevalence of asthma.