Prevalence of asthma and allergy in adults shows still an increasing trend in Finland during the past 15 years

Introduction: Asthma and allergic diseases are a major public health problem, and their prevalence has been increasing in Finland from 1960s. Aims: To study the prevalence of asthma, hay fever or other allergic rhinitis, allergic eye symptoms, and atopic (itching) eczema, and their 15 year trends, among the Finnish adult population. Methods: Study population consists of the participants of the National FINRISK Study in 1997, 2002, 2007 and 2012. In each survey, the sample included 10000 (in 2012 8000) randomly selected 25 - 64 year old men and women. Participation rate varied between 65 and 72%. Data were collected using standardized self-administered questionnaires based on the European Respiratory Health Survey (ERHS). Results: The prevalence of physician diagnosed asthma increased from 6.1% to 9.5% in men (p <0.001) and from 7.8% to 10.8% in women (p <0.001) from 1997 to 2012. In 1997, allergic rhinitis, allergic eye symptoms and atopic dermatitis in the past 12 months prior the survey were reported by 25.8%, 18% and 16.7% of men, and 32.5%, 25.9% and 17.6% of women. In 2012 the prevalences were 28.1%, 21.2% and 14.7% in men and 36.1%, 28.3% and 17.8% in women, respectively. The prevalence of asthma and allergic symptoms increased in the age group 25 to 45 years, but remained at the same level in the older age group. Conclusions: Asthma and allergic symptoms are common in Finland, and their prevalence has been increasing in the past 15 years among the younger people. All symptoms are more prevalent in women than in men. The increase may be explained by the cohort effect, ie. the younger generations have higher prevalence of asthma and allergy compared to the older ones.