Leif Rosenhall

Symptoms related to asthma and chronic bronchitis in three areas of Sweden

Does the prevalence of respiratory symptoms differ between regions? As a part of the European Community Respiratory Health Survey, we present data from an international questionnaire on asthma symptoms occurring during a 12 month period, smoking and symptoms of chronic bronchitis. The questionnaire was mailed to 10,800 persons aged 20-44 yrs living in three regions of Sweden (Västerbotten, Uppsala and Göteborg) with different environmental characteristics. The total response rate was 86%. Wheezing was reported by 20.5%, and the combination of wheezing without a cold and wheezing with breathlessness by 7.4%. The use of asthma medication was reported by 5.3%. Long-term cough and/or morning cough together with problems with phlegm was reported by 12.8%; the prevalence being highest in the most polluted area (Göteborg). When using multivariate analysis, no significant difference in asthma-related symptoms was found between the centres. Women reported cough more frequently, but otherwise gender did not influence symptom prevalence. Our results indicate that bronchitis symptoms occur more frequently in Göteborg, the most polluted of the Swedish centres, but that the prevalence rates of asthma-related symptoms do not differ between these three regions.

Prevalence of positive skin prick tests, allergic asthma, and rhinoconjunctivitis in teenagers in northern Sweden

The prevalence of positive skin prick tests (SPT) for common allergens and symptoms of allergic rhinoconjunctivitis or asthma was investigated in Umeå in northern Sweden in 1987. Skin prick tests with 10 allergens common in Sweden and a questionnaire were used to examine 1112 teenagers. All subjects with a positive skin prick test or symptoms were interviewed, and they were further investigated by a serum specific IgE test, a ventilatory lung function test, and a physical examination. At least one skin prick test was positive in 43% of the subjects. Ninety‐three percent had at least one positive skin prick test to one of the three most common allergens: cat, timothy grass, and birch. The prevalence of current allergic rhinoconjunctivitis was 17%, current allergic asthma 2.8%, and current asthma (both allergic and nonallergic) 6.8%. Multiple logistic regression analysis showed that the most important risk factors for current asthma were sex (being a girl) and atopy. Heredity of asthma or rhinoconjunctivitis and being born in the winter (October‐March) also increased the risk. In atopic subjects, having a mother who smoked and heredity of asthma increased the risk. For allergic rhinoconjunctivitis, heredity increased the risk of getting rhinoconjunctivitis.

AN INTERVIEW STUDY TO ESTIMATE PREVALENCE OF ASTHMA AND CHRONIC BRONCHITIS The Obstructive Lung Disease in Northern Sweden Study

A questionnaire of respiratory symptoms and diseases completed by 6610 adults in 3 age cohorts (35–36 y; 50–51 y and 65–66 y) in northern Sweden was followed-up by interview and lung function testing of 1243 subjects with asthmatic or bronchitic symptoms and 263 subjects assessed from the postal questionnaire as being healthy. We report the results of this follow-up study.According to the criteria used, 292 subjects (5.1% of the original study sample) were diagnosed as having asthma. Out of the 1243 subjects 334 (5.9% of the original study population) were diagnosed as having chronic bronchitis.However, examination of the 263 subjects who were healthy according to the postal questionnaire showed that elderly smokers, in particular, under-reported bronchitic symptoms; taking this into account, the prevalence of chronic bronchitis is estimated to be of the order of 9%. Diagnostic difficulties were noted in 70 subjects (corresponding to 1.2% of the original study sample) in whom asthma or chronic bronchitis were strongly suspected. Further investigation of these subjects was considered necessary. In this cross-sectional study, FEV1 <80% of predicted values was found in 36% of subjects diagnosed as having asthma and in 31% of those with chronic bronchitis. Among subjects with attacks of breathlessness and wheezing, diagnostic criteria often used for asthma in questionnaire studies, 70% were diagnosed as having asthma. Of those with chronic productive cough, 62% were diagnosed as having chronic bronchitis. We consider that trained nurses provide reliable data that may be used in epidemiological surveys of obstructive lung diseases.

Skin prick tests and specific IgE in adults from three different areas of Sweden

The aims of this part of the European Respiratory Health Survey were to estimate the prevalence of atopic sensitization to inhalant allergens among adults in three different areas of Sweden and to investigate the association between sensitization and certain risk factors. Randomly selected subjects aged 20–46 years from Göteborg, Uppsala, and Västerbotten were investigated with the skin prick test (SPT), analyses for specific IgE antibodies in serum (specific IgE) and total serum immunoglobulin E (total IgE), and a questionnaire. SPT was performed in 1572 subjects and analyses of specific IgE in 1470. One or more positive SPT were found in 35.6% and one or more positive specific IgE in 31.7% ‐ approximately the same values in all three areas. Birch, grass, cat, and dog were the most frequent sensitizing agents and occurred at similar prevalences, i.e., around 15%, in all areas. The SPT to mite was positive in 14.1% in Göteborg, 7.4% in Uppsala, and 7.9% in Västerbotten. A positive SPT to pellitory of the wall (Parietaria), not described previously in Sweden, was found in 3.4% in Göteborg. Living in Göteborg was independently associated with a higher risk of a positive SPT to mite and Parietaria. Heredity, male sex, and low age were independently associated with atopy. Birth in the Scandinavian countries was independently associated with sensitization to cat, whereas birth in other countries was associated with sensitization to mite. The overall prevalence of atopy was similar in the three Swedish areas, but the sensitizing allergens varied. There is an indication that sensitization is increasing in the population, as low age was associated with sensitization. Sensitization to cat, but not to mite, appears to be particularly important in persons born in the Scandinavian countries.

High dose inhaled budesonide in the treatment of severe steroid-dependent asthmatics: a two-year study

Thirty‐eight patients with chronic asthma requiring continuous oral corticosteroid treatment took part in a 2‐year study. Budesonide, a new inhalation steroid with high topical activity and low systemic effects, was given in stepwise increasing doses from 200 μg daily up to 800–1600 μg daily and prednisolone doses were decreased gradually on an individual basis. After 2 years, 18 patients had been able to cease oral prednisolone treatment, 11 had decreased the dose by 50%, three by 50% and two patients had increased their dose. At the end of the study the majority of patients (26) were using 800 ng budesonide daily and seven, 1200 μg or more daily. There were two dropouts, one due to local side effects and one to a severe pulmonary eosinophilia. Ten patients had local side effects in the form of hoarseness and/or sore throat, and 13 patients had steroid withdrawal symptoms such as arthralgia and myalgia. The asthma conditon in all patients was improved, as indicated by the reduced need for hospital admissions. The results indicate that high doses of budesonide should be tried before starting maintenance therapy with oral steroids.

Epidemiology of respiratory symptoms, lung function and important determinants : Report from the Obstructive Lung Disease in Northern Sweden project

SETTING Cross-sectional epidemiological study based on a representative sample of the general population in northern Sweden. OBJECTIVES To assess the prevalence of respiratory symptoms, the role of respiratory symptoms as indicators of impairment of lung function, and to define risk factors for respiratory symptoms and lung function impairment. DESIGN The 1340 subjects of 6610 who reported respiratory symptoms suggestive of asthma or chronic bronchitis in a postal questionnaire study were invited to a structured interview and lung function tests. A control group of 315 subjects was also invited. Risk factors were assessed from the postal questionnaire. RESULTS 400 subjects in the symptomatic group had attacks of breathlessness and wheezing, while none in the control group had them, corresponding to 7% of the original study population. Chronic productive cough was present in 537 subjects, of whom 13 were from the control group, suggesting that 12% of the original study population had this symptom. Persistent wheeze was the symptom that predicted the greatest proportion of cases of impaired lung function. Attacks of breathlessness, wheezing, long-standing cough and sputum production were all related to age, smoking and a family history of asthma. Both chronic productive cough and impaired lung function correlated strongly with smoking and age, and their prevalences differed in different socio-economic groups. CONCLUSION Impaired lung function can be predicted from respiratory symptoms. Data collected in postal questionnaires suffice for the identification of risk factors. Combinations of symptoms gave greater odds ratios than individual symptoms.

Methacholine reactivity and asthma. Report from the Northern Sweden Obstructive Lung Disease Project.

Methacholine tests were used in an epidemiologic study of the prevalence of asthma and chronic bronchitis in northern Sweden. Of 6610 subjects in three age groups from eight representative geographic areas in the northernmost province of Sweden, 5698 (86%) completed a postal questionnaire on respiratory symptoms, and 1506 underwent a structured interview and a lung function test. A total of 292 (5%) were diagnosed as having asthma. A subsample of 284 subjects (of 320 invited) classified at the interview as having asthma (n= 98) or as having respiratory symptoms that might be due to asthma but not fulfilling the interview criteria for the diagnosis of asthma (n= 186) underwent a methacholine test. Subjects who, before the interview study, already had a well‐defined asthma diagnosis were not invited to the methacholine testing. Of those 98 subjects classified as having asthma, 61 % reacted to methacholine doses ≤ 4 mg/ml and 79% to doses ≤ 8 mg/ml, while the corresponding figures in the symptomatic but nonasthma group were 20% and 34%, respectively. The results show that a carefully performed structured interview accurately diagnoses asthma in epidemiologic studies. The methacholine tests provide important diagnostic information primarily in subjects in whom the medical history is equivocal.

Epidemiology of respiratory symptoms, lung function and important determinants

SETTING Cross-sectional epidemiological study based on a representative sample of the general population in northern Sweden. OBJECTIVES To assess the prevalence of respiratory symptoms, the role of respiratory symptoms as indicators of impairment of lung function, and to define risk factors for respiratory symptoms and lung function impairment. DESIGN The 1340 subjects of 6610 who reported respiratory symptoms suggestive of asthma or chronic bronchitis in a postal questionnaire study were invited to a structured interview and lung function tests. A control group of 315 subjects was also invited. Risk factors were assessed from the postal questionnaire. RESULTS 400 subjects in the symptomatic group had attacks of breathlessness and wheezing, while none in the control group had them, corresponding to 7% of the original study population. Chronic productive cough was present in 537 subjects, of whom 13 were from the control group, suggesting that 12% of the original study population had this symptom. Persistent wheeze was the symptom that predicted the greatest proportion of cases of impaired lung function. Attacks of breathlessness, wheezing, long-standing cough and sputum production were all related to age, smoking and a family history of asthma. Both chronic productive cough and impaired lung function correlated strongly with smoking and age, and their prevalences differed in different socio-economic groups. CONCLUSION Impaired lung function can be predicted from respiratory symptoms. Data collected in postal questionnaires suffice for the identification of risk factors. Combinations of symptoms gave greater odds ratios than individual symptoms.