Secular trends of allergic asthma in Danish adults. The Copenhagen Allergy Study.
Numerous studies have reported increases in asthma prevalence among children world-wide. Less is known about similar trends in adults. We aimed to investigate whether the prevalence of allergic asthma symptoms had increased in an adult general population. Two cross-sectional surveys using identical methods were carried out in 1989 and 1998. A one-page questionnaire on respiratory symptoms was mailed to random samples of 15-41-year-olds living in Copenhagen. The response rates were 86.6% (3624/4185) and 78.8% (2402/3048) in 1989 and 1998, respectively. The questionnaire was validated with specific immunoglobilin E (IgE) positivity as the reference in a random sample of responders in connection with both surveys. We found a significantly increased prevalence of subjects who reported shortness of breath on exposure to pollens (6.6% 0 s. 10.3%, odds ratio 1.61, 95% CI 1.34-1.95), furry animals (5.4% vs. 7.6%, odds ratio 1.45, 95% CI 1.17-1.79), and house dust (7.8% vs. 10.2%, odds ratio 1.35, 95% CI 1.12-1.61). The validation of these symptoms showed that the positive predictive values were reasonably stable over time, which may support that a true increase in allergic asthma has occurred. In conclusion, the prevalence of allergic asthma symptoms increased significantly in this adult general population over a 9-year period.
Linneberg
A
A
Centre for Preventive Medicine, Department of Internal Medicine M, Glostrup Hospital, Denmark. alli@glostruphosp.dk
Nielsen
N H
NH
Madsen
F
F
Frølund
L
L
Dirksen
A
A
Jørgensen
T
T
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D000818:Animals; D000829:Animals, Domestic / Q000276:immunology; D001249:Asthma / Q000453:epidemiology* / Q000276:immunology; D002415:Cats; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D004285:Dogs; D004391:Dust; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011058:Pollen / Q000276:immunology; D011237:Predictive Value of Tests; D015995:Prevalence; D012221:Rhinitis, Allergic, Perennial / Q000453:epidemiology; D006255:Rhinitis, Allergic, Seasonal / Q000453:epidemiology
D000485:Allergens; D004391:Dust; D007073:Immunoglobulin E