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RESPIRATORY MEDICINE(1999) 93, 7984309
Increasing prevalence of asthma but not of chronic bronchitis in Finland? Report from the FinEsS-Helsinki study
I? PALLASAHO*, B. LUNDBACK ?-!I, S. L. LAW&*, E. J~NSSON~, J. KOTANIEMI~, A. R. A. SOVIJWRVI~ AND L. A. LAITINEN*
*Department of Medicine, Division of Xespirato y Medicine, Helsinki University Central Hospital, Helsinki, Finland %!espiratoy Epidemiology Unit, Department of Occupational Medicine, National Institute for Working Life, StockholmlSolna and Umea” and %he OLIN Study Group, Central Hospital of Norrbotten, Lulea-Boden, Sweden §Department of Pulmona y Medicine, Liinsi-Pohja Hospital, Kemi, Finland 7Laboratoy Department, Division of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, Helsinki, Finland
To assessthe prevalence of asthma, chronic bronchitis and respiratory symptoms, and to calculate risk factors for them, we performed a postal survey in Helsinki, the capital of Finland. During the spring of 1996, questionnaires were mailed to a random sample of 8000 individuals aged 20-69. The total response rate was 76%, with 6062 complete answers. The prevalence of having ever had asthma was 7*2%, physician-diagnosed asthma was 6.6% and physician- diagnosed chronic bronchitis was 3.1%. Asthma was significantly more common among women than men, but no gender differences existed in prevalence of chronic bronchitis. The most common respiratory symptom was sputum production when coughing, reported by 27%. During the previous 12 months, wheezing had occurred in 20% and attacks of shortness of breath in 13% of subjects. Generally, the prevalence of different respiratory symptoms were significantly higher among smokers. The most important risk factor for asthma was a family history of asthma (Odds ratio:OR 3.3). Multivariate analysis revealed that being a member of the socioeconomic group, manual workers, was associated with a significantly increased risk for chronic productive cough (OR 1.7), and for wheezing during the previous 12 months (OR 1.7). Manual workers of both genders had the highest prevalence of asthma, chronic productive cough and wheezing during the previous 12 months. The prevalence of asthma in Helsinki was higher than previously found in Finland, and was at a similar level to that of other Nordic countries. In contrast, prevalence of chronic bronchitis was lower than previously shown in Finland.
RESPIR. MED. (1999) 93, 7984309 0 1999 HARCOURT PUBLISHERS LTD
Introduction asthma in the ECRHS report varied from 2.0% in Tartu, Estonia, to 11.9% in Melbourne, Australia. The prevalence Incidence and prevalence of asthma have increased, of wheezing was lowest in Bombay, India, (4.1%) and particularly among children, adolescents and young adults, highest in Melbourne (28.8%) (5). all over the world (l-3). The European Community Epidemiological studies have shown a lower prevalence Respiratory Health Survey (ECRHS), has revealed wide of asthma in Finland than in other Nordic countries, or in geographical variation in prevalence of asthma and use of England, the U.S.A., Canada or Australia (613). The asthma medication worldwide (4). The prevalence of latest reports, however, have revealed a tendency towards increasing prevalence of asthma in Finland (1,14), where Received 4 January 1999 and accepted in revised form annual incidence of persistent asthma has risen 90% from 25 June 1999. 1986 to 1993 among young women aged 15 to 29 (1). Correspondence should be addressed to Paula Pallasaho, MD, In Finland, as well as in other Nordic countries, Department of Medicine, Division of Respiratory Medicine, prevalence and incidence of chronic bronchitis and chronic Helsinki University Central Hospital, Haartmaninkatu 4, 00290 obstructive pulmonary disease (COPD) have been studied Helsinki, Finland. E-mail: [email protected] less than those of asthma. Variation in criteria for COPD
0954-6111/99/110798+12 $12.00/O 0 1999 HARCOURT PUBLISHERS LTD ASTHMA mD CHRONIC BRONCHITIS PREVALENCE 799 makes comparisons between different studies difficult. The methods, including the selection of the study sample, According to the Obstructive Lung Disease in Northern were the same as used in other centres of the FinEsS study, Sweden studies (OLIN), prevalence of physician-diagnosed a comparative survey carried out in Finland, Estonia and chronic bronchitis was 4%, and that of self-reported Sweden, aiming to assessprevalence and risk factors for chronic productive cough 10% (15). In Finland, preva- airway disorders and type-l-allergy. The present study was lences of chronic bronchitis and bronchitic symptoms have approved by the Ethics Committee of the Department of earlier been reported to be even higher (16). Medicine of Helsinki University Central Hospital. National campaigns for diagnosis and treatment of asthma and COPD have recently been started in many countries. We aimed to assess the current prevalence of QUESTIONNAIRE asthma, chronic bronchitis, respiratory symptoms and use of asthma medication in Helsinki, the capital of Finland. A The FinEsS questionnaire was based on the Swedish OLIN further aim was to examine the effects of smoking, family study questionnaire (15), developed mainly from the British history of airway diseases and socioeconomic status on Medical Research Council (18) and Tucson questionnaires prevalences of these conditions. (19). The OLIN questionnaire has been used in several Nordic studies (15, 20-22). In addition, the FinEsS questionnaire included two questions from the IUATLD questionnaire (23-25), questions also used in the ECRHS Material and Methods (5). The questionnaire included items about family history, asthma, chronic bronchitis, allergic rhinitis and various STUDY AREA respiratory symptoms such as cough, sputum production, wheeze, chest tightness and attacks of shortness of breath. Helsinki is located on the southern coast of Finland, on the Questions were also included about the use of asthma Baltic Sea, with 539 363 inhabitants in 1997, which medication, smoking habits and socioeconomic group comprised 10.5% of the whole population of Finland. (Appendix 1). The urbanized area includes more than one million people. The climate of Helsinki is cool; the average temperature over the past 30 yr has been 5°C. The coldest month is DEFINITIONS January (- 6°C) and the warmest is July (17°C) (17). The quality of the air is good, with levels of SO2 and NO2 In the present study, asthma was defined in two separate decreasing during recent decades. ways. The subjects condition was classified as having ever had asthma when they answered ‘yes’ to the question: ‘Have you now or have you had asthma?‘. Physician- STUDY POPULATION diagnosed asthma was based on the question ‘Have you been diagnosed as having asthma by a doctor?‘. Postal questionnaires were sent to 8000 individuals aged Those who answered ‘yes’ to the question: ‘Have you 20-69 living in the city of Helsinki, during the spring of now, or have you had, chronic bronchitis or emphysema?’ 1996. The study sample was obtained from the Population were classified as having ever had chronic bronchitis. Register Centre, randomized by lo-yr age-cohorts and by Physician-diagnosed chronic bronchitis was based on the gender. Four subjects were dead and 119 subjects had question ‘Have you been diagnosed as having chronic moved out of Helsinki. Reminders were sent twice, with the bronchitis or emphysema by a doctor?‘. final response rate of 75.8% comprising answers from 6062 Those who reported sputum production when coughing subjects. Table 1 shows the distribution by age, sex and on most days, during at least 3 months in 2 successiveyears, smoking habits. were interpreted to have chronic productive cough. Those
TABLE 1. Study population by age, sex and smoking habits
20-44 years 45-69 years Total
Women Men Women Men Women Men All
Study sample (n) 2433 2219 1794 1554 4227 3773 8000 Participants (n) 1963 1431 1499 1169 3462 2600 6062 ("/I 81 65 84 75 82 69 76 Non-smokers (%) 53 45 57 35 55 40 49 Ex-smokers (%) 12 12 17 30 14 20 17 Smokers (%) 35 43 26 35 31 39 34 800 P. PALLASAHO ETAL.
who had stopped smoking at least 12 months prior to the associated with chronic productive cough for all ages, with study were classified as ex-smokers. 32% of the elderly male smokers reporting this symptom (Figs. 2 and 3). ANALYSES The chi-square test was used for bi-variate comparisons, ASTHMA AND CHRONIC BRONCHITIS and one way ANOVA (analysis of variance) for testing for The prevalence of having ever had asthma was 7.2% and trends. The simultaneous effects of different independent physician-diagnosed asthma was 6.6%. Both were signifi- variables on asthma and respiratory symptoms were cantly more common in women than men, and more calculated by multiple logistic regression analysis. The prevalent in the elderly (Fig. 3). Common symptoms in independent variables in the analyses were age, sex, family subjects with physician-diagnosed asthma were attacks of history of asthma or obstructive airway diseases (chronic shortness of breath during the previous 12 months (76%), bronchitis or emphysema), smoking habits and socio- wheezing during the previous 12 months (72%) chest economic group. Socioeconomic group was based on tightness upon awakening (63%), sputum production when profession, classified according to the Nordic classification coughing (53%), breathlessness when walking on the level system for occupations (23). (44%) and long-standing cough (43%). Of all asthmatics, 65% reported using asthma medication, with 80% of those asthmatics who, during the previous 12 months, had had Results attacks of shortness of breath using asthma medicines. Six percent of the whole population sample reported use of PARTICIPATION AND SMOKING HABITS asthma medication (women 7.0% and men 4.6%, The participation rate was 82% in women and 69% in men, P Attacks of shortness of breath in 0.012 Wheezing in previous 12 months 0.195 0.034 Tightness in chest when waking up 0.016 Longstanding cough Sputum production when coughing 0.002 0.105 fi Chronic productive cough < 0.001 0.228 50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0% 20-29 years 30-39 years 40- 49 years SO-59 years 60-69 years FIG. 2. Prevalence of sputum pr tion in men and women by smoking habits and age. - -: male non-smoker; - + -: male ex-smoker; -u-: male smoker; : female non-smoker; +: female ex-smoker; +-: female smoker. 25% 20% 15% 10% 5% 0% I I 1 I 20-29 years 30-39 years 40-49 years 50-59 years 60-69 years FIG. 3. Prevalence of chronic producti ugh in men and women by smoking habits and age. -: male non-smoker; -+- : male ex-smoker; -m-: male smoker; : female non-smoker; +: female ex-smoker; +: ale smoker. 0.0% 1.0% 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% 8.0% 9.0% 10.0 Difference (P-value) by Age Sex Smoking Ever asthma 6.9% Physician-diagnosed asthma < 0.001 0.007 0.116 16.1% ,,. i,I,, 8.0% Use of asthma medicines Ever chronic bronchitis or emphysema < 0.001 0.560 Physician-diagnosed chronic bronchitis 4 0.001 0.207 FIG. 4. Prevalence of having ever had asthma, Physician-diagnosed asthma, ever chronic bronchitis and physician-diagnosed chronic bronchitis, and use of asthma medication by age and sex. Difference (P-value) by age, sex and smoking. !Y: male (2044 yr); q : female (2044 yr); 0: male (45-69 yr); 0: female (45-69 yr). $ TABLE 2. Prevalence of physician-diagnosed asthma, chronic productive cough and wheezing in men (m) and women (w) by socioeconomic group. Difference (P-value) by age, sex and smoking habits Physician-diagnosed asthma Chronic productive cough Wheezing last 12 months Difference by Difference by Difference by Occupation Sex 2044 45-69 age sex smoking 2044 45-69 age sex smoking 2044 45569 age sex smoking v-s v-s yrs yrs w yrs Self-employed m 2.1 % 4.1 % 0.21 0.42 0.21 8.3 % 15.1 % 0.04 0.60 0.81 16.7 % 12.3 % 0.36 1.00 0.03 W 2.3 % 8.5 % 4.7 % 14.9 % 16.3 % 10.6 % Manual workers m 5.7 % 7.4 % 0.18 0.04 0.49 13.8 % 24.2 % Housewives W 6.7 % 3.8 % 0.45 0.52 0.01 4.8 % 15.4 % 0.03 0.42 ‘0.07 14.3 % 17.3 % 0.79 0.25 (P = 0.046) in the younger people among intermediate level The prevalence rate of having ever had asthma of 7.2% employees and professionals (Table 2). for the whole sample and 6.1% among young men (20-29) was considerably higher than in previous studies from Finland: prevalence of asthma was reported to be 1.8% MULTIVARIATE RELATIONSHIPS among conscripts in 1989, and prevalence rates from 2.7% to 4.1% were shown in an adult population in 1980 (14,30). Odds ratios (OR) between different independent variables The OLIN study from northern Sweden revealed a 1986 which might have influenced incidence of physician- prevalence rate of 6% for ‘ever had asthma’ (15). Swedish diagnosed asthma, and the symptoms wheezing during the data suggest somewhat higher prevalence of asthma in previous 12 months and chronic productive cough, were Sweden today (31). Our results suggests that prevalence of calculated by multiple logistic regression analysis (Table 3). asthma had increased in Finland to approximately the same Significant risk factors for asthma were a family history of level as in Sweden. Prevalence of having ever had asthma asthma (OR 3.3) and being female (OR 1.3). Manual was slightly higher than of physician-diagnosed asthma in workers (OR 1.9) and students/conscripts (OR 1.6), as well both men and women, suggesting that some people may as ex-smokers (OR 1.3), showed strong trends toward have had asthma, or asthma symptoms, earlier in life, but increased risk. do not currently have asthma. Asthma was significantly Significant risk factors for chronic productive cough were more prevalent among women, and women using asthma current smoking of five or more cigarettes per day (5-14 medication more often were also trends in the ECRHS and cigarettes, OR 1.8, and > 14 cigarettes, OR 4. l), being aged in OLIN studies (13,32). The high prevalence rate of 45-69 (OR 1.6): being a manual worker (OR 1.7), family respiratory symptoms among asthmatics was surprising, history of chronic bronchitis or emphysema (OR 1.7) and and raised the question of whether treatment of asthmatics ex-smoking (OR 1.5), whereas no gender differences could is adequate, despite the preference for inhaled corticoster- be shown. The risk-factor pattern for wheezing during the oids in Finland. previous 12 months was similar to that of productive cough A family history of asthma was the most important risk in regard to smoking habits, while the influence of heredity factor for asthma, in concordance with other studies and socioeconomic group showed similarities in their (32,33). According to multivariate analyses, being a manual influence on asthma. Age and gender had no influence on worker was a notable risk factor for several conditions, wheezing. which could partly be explained by occupational exposure Dividing smokers into three categories: those who provoking asthma. The annual incidence of occupational smoked less than five cigarettes per day, those who smoked asthma increased from 1986-1993, in Finland rising by 5-14 and more than 14 cigarettes per day, did not have any 70%, according to a recent report (1). Approximately one- significant impact on results compared to analysis where the third of the Finnish work force in 1992 was exposed to current smokers were analysed in one group. respiratory pollutants at work and 13% to occupational allergens (34). A recent Swedish study supports an association between occupational exposure to non-specific Discussion air pollution and development of bronchial asthma (35). As for prevalence rates for chronic productive cough and In analytical epidemiological studies, questionnaire answers chronic bronchitis, these were considerably lower in men about asthma, mainly physician-diagnosed asthma, gene- than in previous Finnish studies. Prevalence of chronic rally have a high specificity and a high reliability (27;28). bronchitis was 27% in men and 5.5% in women in 1965, The FinEsS questionnaire is based on validated question- and somewhat lower in men in the early 80s (36). The naires, with questions about self-reported asthma (ever had change can in part be explained by the changes in smoking asthma) and physician-diagnosed asthma included. The habits (16). Of the whole sample 3.7% reported physician- response rate in our study was similar to the median diagnosed chronic bronchitis, the same level as in the OLIN response rate of the ECRHS. As in the ECRHS, the studies (4%) and in earlier other Nordic studies (7-9,15). participation rate was higher for women and for the elderly However, the low prevalence of physician-diagnosed (5). chronic bronchitis (19%) among those reporting chronic A high prevalence of respiratory symptoms was found in productive cough suggests a considerable rate of undiag- the whole sample. Compared to OLIN study results from nosed chronic bronchitis. The prevalence of chronic northern Sweden, the prevalence of cough and sputum productive cough was found to be still higher in the present production were higher in Helsinki (15). Sputum produc- study than in recent Swedish studies (15; 33). tion when coughing was more common in women, and Chronic productive cough was chosen for risk factor chronic productive cough was more common in women analysis instead of chronic bronchitis, as the latter yielded a aged 20-44 than in men. This may be explained by the fact considerable underestimate of the condition. Current that smoking has become more common in women and less smoking was the major risk factor for chronic productive common in men during recent decades; 79% of women cough, as expected, followed by a family history of chronic were non-smokers in Alanko’s study (1966) versus 55% in bronchitis and being a manual worker. In women aged 60 our study, while 56% of men were smokers in 1966 versus to 69 years 61% of those reporting chronic productive 39% in our study (6). Women may also be more sensitive to cough were non-smokers, which might be explained in the effects of smoking than men (29). part by occupational exposures, including exposure to .v 7 F $ TABLE 3. Risk factors (OR) for chronic productive cough, wheezing during the previous 12 months and physician-diagnosed asthma calculated by multiple logistic regression 8 analysis 1.$! Independent variables Dependent variables Chronic productive cough Wheezing Asthma Variables Categories OR 95% Cl OR 95% Cl OR 95% Cl Sex Male 1 1 1 Female 1.13 0.95-1.34 1.01 0.88-1.16 1.27 1.02-1.59 Age 2044 yr 1 1 1 45-69 yr 1.57 1.32-1.86 0.96 0.83-1.10 1.20 0.96-1.49 Family history of asthma No 1 1 Yes 2.08 1.78-2.43 3.32 2.674.13 Family hisotry of obstructive airway disease No 1 Yes 1.72 1 e442.06 Smoking habits Non-smokers 1 1 1 Ex-smokers 1.50 1.18-1.90 1.53 1.25-l-87 1.25 0.941~66 Smokers, < 5 cigarettes/day 1.01 0.69-1.47 1.51 1.16-1.96 0.86 0.55-1.34 Smokers, 5-14/day 1.79 1.40-2.30 2.53 2.08&3.07 1.22 0.90-1.66 Smokers. > 14/day 4.08 3.29-5.07 4.33 3.59-5.23 0.71 0.49-l .o 1 Socio-economic group Self-employed 1 1 1 Manual workers 1.69 1.042073 1.69 1.11-2.57 1.91 0.9553.84 Assistant non-manual 1.01 06l1.67 1.37 ‘0.89-2.11 1.46 0~71-3~00 > Intermediate and Professionals 1.14 0.70-1.86 1.40 0.91-2.14 1.54 0.76-3.11 Housewives o-95 0.45-2.00 1.14 0.62-2.09 1.20 0.46-3.15 Students and Conscripts 1.09 06-1.95 ” 1.85 1.10-3.43 1.63 O-75-3.56 Profession unknown 1.48 0.76-2.89 1.94 1.09-3.38 2.40 0.99-5.86 ASTHMAANDCHRONICBRONCHITISPREVALENCE 807 environmental tobacco smoke, together with the low findings and socio-economic factors. Stand J Respir Dis proportion of smokers in that age group. In addition, 1967; 48: 330-342. mucociliary clearance decreases with increasing age (37). 8. Kiviloog J, Irnell L, Eklund G. The prevalence of Being a manual worker was a significant risk factor for bronchial asthma and chronic bronchitis in smokers chronic productive cough and wheezing, and to some extent and non-smokers in a representative Swedish popula- a risk factor for asthma as well, indicating that there could tion. Stand J Respir Dis 1974; 55: 262-276. be occupational factors provoking respiratory symptoms 9. Gulsvik A. Prevalence and manifestations of obstruc- and diseases in their occupational environment. tive lung disease in the city of Oslo. Stand J Respir Dis , In conclusion, there seemed to be a considerable 1979; 60: 286-296. prevalence of respiratory symptoms among the population 10. Stjernberg N, Eklund A, Nystrom L, Rosenhall L, of Helsinki. The prevalence of asthma had increased Emmelin A, Stromqvist LH. Prevalence of bronchial compared to that in previous studies and was similar to asthma in a community in northern Sweden: relation to prevalence in other Nordic countries. Asthmatics also had environmental and occupational exposure to sulfur many respiratory symptoms, suggesting that their asthma dioxide. Eur J Respir Dis 1985; 67: 4149. medication might be inadequate. The prevalence of chronic 11. Vesterinen E, Kaprio J, Koskenvuo M. Prospective productive cough and chronic bronchitis were lower than study of asthma in relation to smoking habits among shown previously, but there seemed to be a noticeable rate 14,729 adults. Thorax 1988; 43: 534-549. of undiagnosed chronic bronchitis. Manual workers were at 12. Fleming DM, Crombie DL. Prevalence of asthma and significant risk of, having chronic productive cough, hay fever in England and Wales. Br Med J 1987; 294: wheezing and, to some extent, asthma. Such a frequency 279-283. of respiratory symptoms and undiagnosed chronic bron- 13. Sears MR. Epidemiology in asthma. In: Barnes PJ, chitis suggests clinical follow-up studies. Rodger IW, Thomson NC, ed. Asthma Basic mechan- isms and clinical management. Academic Press. 2. Acknowledgements Edition. 1992. 14. Haahtela T, Lindholm H, Bjiirksten F, Koskenvuo K, This study was supported by a government subsidy. Laitinen LA. Prevalence of asthma in Finnish young Associate Professor Matti Kataja is acknowledged for men. Br MedJ 1990;301:266-268. assistance with statistics. 15. Lundback B, Nystrijm L: Rosenhall L, Stjernberg N. Obstructive lung disease in northern Sweden: respira- tory symptoms assessed in a postal survey. Eur Respir J 1991; 4: 257-266. 16. Huhti E. Prevalence of respiratory symptoms, chronic References bronchitis and pulmonary emphysema in a Finnish 1. Reijula K; Haahtela T, Klaukka T, Rantanen J. rural population. Acta Tuberc Pneumonol Stand 1965; Incidence of occupational asthma and persistent (Suppl. 61): l-111. asthma in young adults has increased in Finland. Chest 17. Climatological Statistics in Finland 1961-1990. The 1996; 110: 58861. Finnish Meteorological Institute. 2. Yunginger J, Reed C, O’Connell E, Melton LJ, 18. Medical Research Council’s Committee on the aetiol- O’Fallon W, Silverstein M A. Community-based study ogy of chronic bronchitis. Standardised questionnaires of the epidemiology of asthma. Am Rev Respir Dis on respiratory symptoms. Br Med J 1960; ii: 1665. 1992; 146: 8888894. 19. Lebowitz MD. The trends in airway obstructive disease 3. Aberg N, Hesselmar B, Aberg B, Eriksson B. Increase morbidity in the Tuscan Epidemiological Study. Am of asthma, allegic rhinitis and eczema in Swedish school Rev Respir Dis 1989; 140: s35-~41. children between 1979 and 1991. Clin Exp Allergy 1995; 20. Lundback B, Stjernberg N, Nystrijm L, Lundback K, 25:815-819. Lindstrom M, Rosenhall L. An interview study to 4. Janson C, Chinn S, Jarvis D, Burney P. Physician- estimate prevalence of asthma and chronic bronchitis- diagnosed asthma and drug utilization in the European the Obstructive Lung Disease in Northern Sweden Community Respiratory Health Survey. Eur Respir J Study. Eur J Epidemiol 1993; 9: 123-133. 1997; 10: 1795-1802. 21. Lundback B, Stjernberg N, Nystrijm L et al. Epide- 5. European Community Respiratory Health Survey. miology of respiratory symptoms, lung function and Variations in the prevalence of respiratory symptoms, their important determinants. Tuber Lung Dis 1994; 75: self-reported asthma attacks, and use of asthma 116-126. medication in the European Community Respiratory 22 Lundback B, Stjernberg N, Rosenhall L, Lindstriim M, Health Survey (ECRHS). Eur Respir J 1996; 9: Jiinsson E, Andersson S. Methacholine reactivity and 687-695. asthma. Report from the Northern Sweden Obstructive 6. Alanko K. Prevalence of asthma in a Finnish rural Lung Disease Project. Allergy 1993; 48: 117-124. population. Stand J Respir Dis 1970; (Suppl. 76) l-64. 23. Burney PGJ, Chinn S. Developing a new questionnaire 7. Julin A, Wilhelmsen L. Bronchial asthma and chronic for measuring the prevalence and distribution of bronchitis in a random sample. Prevalence, clinical asthma. Chest 1987; 91: ~799~83. 808 P. PALL.~~.~H~ETAL. 24. Burney PGJ, Chinn S, Britton JR, Tattersfield AE, b. allergic eye-/nose catarrh (hay-fever) Papagosta AO. What symptoms predict the bronchial C. chronic bronchitis or emphysema response to histamine? Evaluation of a community Have you now or have you had any of the following survey of the Bronchial Symptoms Questionnaire 2. diseases: (1984) of the IUATLD. Int J Epidemiol 1989; 18: asthma 165-173. allergic eye-/nose catarrh (hay-fever) 25. Burney PGJ, Laitinen LA, Perdrizet S et al. Validity and repeatability of the IUATLD (1984) Bronchial chronic bronchitis or emphysema any other lung or airways diseases-if ‘yes’, which? Symptoms Questionnaire: an international compari- son. Eur Respir 1989; 2: 940-945. Have you been diagnosed by a doctor as having 26. National board of occupational safety and health. The asthma? Nordic classification of occupations. Solna, Sweden, 1983. 4. Have you been diagnosed as having chronic bronchitis 21. Samet JM. A historidal and epidemiologic perspective or emphysema by a doctor? on respiratory symptoms questionnaires. Am J Epide- 5. Do you currently use asthma medicines permanently or miol 1978; 108: 435446. as needed? 28. Toren K, Brisman J, Jarvholm B. Asthma and asthma- like symptoms in adults assessed by questionnaires. 6. Have you now or have, you had asthma symptoms Chest 1993; 104: 60&608. during- the last 10 yr (intermittent breathlessne&) or 29. Prescott E, Bjerg AM, Andersen PK, Lange P, Vestbo attacks of breathlessness? The symptoms may exist J. Gender difference in smoking effects on lung function simultaneously with or without cough or wheezing. If and risk of hospitalization for COPD: results from a ‘yes’: Danish longitudinal study. Eur Respir J 1997; 10: a. Have you had these symptoms during the last year (the 822-827. last 12 months)? 30. Heinonen OP, Horsmanheimo M, Vohlonen I, Terho I. Have you had longstanding cough during the last year? EO. Prevalence of allergic symptoms in rural and urban populations. Eur J Refpir Dis 1987; 71 (Suppl: 152): 8. Do you usually have phlegm when coughing, or do you 64-69. have phlegm which is difficult to bring up? If ‘yes’: 31. Lundback BO. Epidemiology. of rhinitis and asthma. a. Do you bring up phlegm on most days during periods Clin Exper Allergy 1998; 28: ~3-310. of at least successive three months? 32. Ronmark E, Lundback B, Jonsson E, Jonsson A-C, b. Have you had such periods during at least two Lindstriim M, Sandstrom T. Incidence of asthma in successive years? adults- report from the Obstructive Lung Disease in Northern Sweden Study. Allergy 1997; 52: 1071-1078. 9. Have you had wheezing, whistling, or a noisy sound in 33. Bjiirnsson E, Plaschke P, Norrman E, et al. Symptoms your chest when breathing? related to asthma and chronic bronchitis in three areas 10. Have you had wheezing or whistling in your chest at of Sweden. Eur Respir J 1994; 7: 21462153. any time in the last 12 months? If ‘no’ go to question 11; 34. Rantanen J, Lehtinen S. Work environment and if ‘yes’: occupational health in Finland. Reviews nr 119. Helsin- a. Have you been at all breathless when the wheezing ki, Finland: Finnish Institute of Occupational Health, noise was present? 1992. Have you had this wheezing or whistling when you did 35. Flodin U, Ziegler J, Jonsson P, Axelson 0. Bronchial not have a cold? asthma and air pollution at workplaces. Stand J of Work, environment and Health 1996; 22: 451456. 11. Have you awakened with a feeling of tightness in your 36. Terho EO, Husman K, Vohlonen I, Heinonen OP. chest at any time in the last 12 months? Atopy, smoking and chronic bronchitis. J Epidemiol 12. Do you have to walk slower than other people of your Community Health 1987; 41: 300-305. age on the level because of breathlessness? 37. Wanner A. Clinical aspects of mucociliary transport. Am Rev Respir Dis 1977; 116: 73-125. 13. Do you usually have breathlessness, wheeze, or severe cough: on effort Applendix 1 T;: in cold weather C. on effort in cold weather during winter QUESTIONNAIRE d. in dusty places e. from cigarette- or tobacco smoke Answers crossing either ‘yes’ or ‘no/do not know’ or writing f. from car exhaust fumes on the appropriate line. g. from strong smelling scents (perfumes, spices, printing ink, cleaner, strong smelling flowers) 1. Have any of your parents, brothers or sisters had: h. from pollens a. asthma i. from animal with fur (cat, dog, horse, cow) ASTHMAAKDCHRONICBROKCHITISPREVALENCE 809 14. Do you smoke? (Smokers also include those who smoke b. Have you been a smoker, but have you stopped a few cigarettes or pipe fills a week, and those who have smoking more than one year ago? stopped smoking during the last 12 months) If ‘yes’ a. How many cigarettes do you smoke per day? Less than 5 In addition, questions about occupation, skiing habits 5-14 and exposure to tobacco smoke during childhood, were also 15 or more asked in Finland. The Finnish questionnaire can be If ‘no’: obtained from the corresponding author on request.